src/data/Contact.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.provider.ContactsContract.CommonDataKinds.Phone;
+import android.provider.ContactsContract.Data;
+import android.telephony.PhoneNumberUtils;
+import android.util.Log;
+
+import java.util.HashMap;
+
+/**     
+  * 
+  * @Package:        net.micode.notes.data
+  * @ClassName:      Contact
+  * @Description:    通过传入的电话号码获取对应的姓名
+ */
+public class Contact {
+    //哈希图型变量sContactCache，用于存储联系人姓名和电话号码的映射关系
+    private static HashMap<String, String> sContactCache;
+    private static final String TAG = "Contact";
+
+    /**
+     * 查找联系人的sql语句:
+     * 执行过程：从phone_lookup中查询符合最小匹配值的raw_contact_id，在data表里找到raw_contact_id，选择电话号码类型，并与传入的电话号码进行精确匹配
+     */
+    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER +  ",?) AND "  + Data.MIMETYPE
+            +  "='"  + Phone.CONTENT_ITEM_TYPE + "'" + " AND " + Data.RAW_CONTACT_ID + " IN " + "(SELECT raw_contact_id "
+            + " FROM phone_lookup" + " WHERE min_match = '+')";
+
+    /**
+     * @method  getContact
+     * @description       通过传入的电话号码获取对应的姓名
+     * @param context     上下文
+     * @param phoneNumber 传入的电话号码
+     * @return string     姓名
+     */ 
+    public static String getContact(Context context, String phoneNumber) {
+        //初始化 sContactCache
+        if (sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+
+        //通过电话号码查找sContactCache，如果命中，直接返回对应的姓名
+        if (sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+
+        //selection:将CALLER_ID_SELECTION中的“+”替换成实际电话号码的最小匹配字符串
+        String selection = CALLER_ID_SELECTION.replace("+", PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+
+        /**查询数据库，返回光标
+         * 数据库表：Data.CONTENT_URI
+         * 查找的列：Phone.DISPLAY_NAME 只显示名称
+         * 查找的sql语句：selection
+         * 替换掉占位符“？”：phoneNumber
+         * 排序方式：不排序
+         */
+        Cursor cursor = context.getContentResolver().query(Data.CONTENT_URI, new String[]{Phone.DISPLAY_NAME},
+                selection, new String[]{phoneNumber}, null);
+
+        //如果光标不为空且移到第一行，即已在数据库中查询到
+        if (cursor != null && cursor.moveToFirst()) {
+            //获取联系人姓名 并将电话号码和联系人姓名的映射关系存到sContactCache中 返回姓名
+            try {
+                String name = cursor.getString(0);
+                sContactCache.put(phoneNumber, name);
+                return name;
+            }
+            //异常处理
+            catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                cursor.close();
+            }
+        }
+        //如果未在数据库中查询到，则记录错误日志
+        else {
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}

src/data/Notes.java

@@ -0,0 +1,305 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.net.Uri;
+
+/**     
+  * 
+  * @Package:        net.micode.notes.data
+  * @ClassName:      Notes
+  * @Description:    集中定义一些常量
+ */
+public class Notes {
+    //定义此应用ContentProvider的唯一标识
+    public static final String AUTHORITY = "net.micode.notes.provider";
+    public static final String TAG = "Notes";
+
+    /**
+     *{@link Notes#TYPE_NOTE } 普通便签
+     *{@link Notes#TYPE_FOLDER }文件夹
+     *{@link Notes#TYPE_SYSTEM } 系统
+     */
+    public static final int TYPE_NOTE     = 0;
+    public static final int TYPE_FOLDER   = 1;
+    public static final int TYPE_SYSTEM   = 2;
+
+    /**
+     * Following IDs are system folders' identifiers
+     * {@link Notes#ID_ROOT_FOLDER } is default folder 默认文件夹
+     * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder 不属于文件夹的便签
+     * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records 存储通话记录
+     * {@link Notes#ID_TRASH_FOLER} 垃圾文件夹
+     */
+    public static final int ID_ROOT_FOLDER = 0;
+    public static final int ID_TEMPARAY_FOLDER = -1;
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+    public static final int ID_TRASH_FOLER = -3;
+
+    //定义Intent Extra 的常量，用于在不同组件之间安全地传递数据
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";
+
+    public static final int TYPE_WIDGET_INVALIDE      = -1;
+    public static final int TYPE_WIDGET_2X            = 0;
+    public static final int TYPE_WIDGET_4X            = 1;
+
+    // 将不同数据类型对应到其MIMEitem类型字符串
+    public static class DataConstants {
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
+    }
+
+    /**
+     * Uri to query all notes and folders
+     */
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+
+    /**
+     * Uri to query data
+     */
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+
+    //Note表数据库列名常量接口
+    public interface NoteColumns {
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * The parent's id for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String PARENT_ID = "parent_id";
+
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+
+        /**
+         * Alert date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ALERTED_DATE = "alert_date";
+
+        /**
+         * Folder's name or text content of note
+         * 如果是文件夹，存储文件夹名字
+         * 如果是便签，存储便签摘要
+         * <P> Type: TEXT </P>
+         */
+        public static final String SNIPPET = "snippet";
+
+        /**
+         * Note's widget id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String WIDGET_ID = "widget_id";
+
+        /**
+         * Note's widget type
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String WIDGET_TYPE = "widget_type";
+
+        /**
+         * Note's background color's id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String BG_COLOR_ID = "bg_color_id";
+
+        /**
+         * For text note, it doesn't has attachment, for multi-media
+         * note, it has at least one attachment
+         * <P> Type: INTEGER </P>
+         */
+        public static final String HAS_ATTACHMENT = "has_attachment";
+
+        /**
+         * Folder's count of notes
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String NOTES_COUNT = "notes_count";
+
+        /**
+         * The file type: folder or note
+         * <P> Type: INTEGER </P>
+         */
+        public static final String TYPE = "type";
+
+        /**
+         * The last sync id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String SYNC_ID = "sync_id";
+
+        /**
+         * Sign to indicate local modified or not
+         * <P> Type: INTEGER </P>
+         */
+        public static final String LOCAL_MODIFIED = "local_modified";
+
+        /**
+         * Original parent id before moving into temporary folder
+         * <P> Type : INTEGER </P>
+         */
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";
+
+        /**
+         * The gtask id
+         * <P> Type : TEXT </P>
+         */
+        public static final String GTASK_ID = "gtask_id";
+
+        /**
+         * The version code
+         * <P> Type : INTEGER (long) </P>
+         */
+        public static final String VERSION = "version";
+    }
+
+    //Data表数据库列名常量接口
+    public interface DataColumns {
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * The MIME type of the item represented by this row.
+         * <P> Type: Text </P>
+         */
+        public static final String MIME_TYPE = "mime_type";
+
+        /**
+         * The reference id to note that this data belongs to
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String NOTE_ID = "note_id";
+
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+        /**
+         * Data's content
+         * <P> Type: TEXT </P>
+         */
+        public static final String CONTENT = "content";
+
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
+        public static final String DATA1 = "data1";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
+        public static final String DATA2 = "data2";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA3 = "data3";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA4 = "data4";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA5 = "data5";
+    }
+
+    //DataColumns接口的实现方式1：文本便签的数据模型
+    public static final class TextNote implements DataColumns {
+        /**
+         * Mode to indicate the text in check list mode or not
+         * <P> Type: Integer 1:check list mode 0: normal mode </P>
+         * data1表示是否是清单模式
+         */
+        public static final String MODE = DATA1;
+
+        public static final int MODE_CHECK_LIST = 1;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";
+
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
+    }
+
+    //DataColumns接口的实现方式2：通话便签的数据模型
+    public static final class CallNote implements DataColumns {
+        /**
+         * Call date for this record
+         * <P> Type: INTEGER (long) </P>
+         * data1表示通话时间戳
+         */
+        public static final String CALL_DATE = DATA1;
+
+        /**
+         * Phone number for this record
+         * <P> Type: TEXT </P>
+         * data3表示电话号码
+         */
+        public static final String PHONE_NUMBER = DATA3;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";
+
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
+    }
+}

src/data/NotesDatabaseHelper.java

@@ -0,0 +1,447 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.util.Log;
+
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+
+/**     
+  * 
+  * @Package:        net.micode.notes.data
+  * @ClassName:      NotesDatabaseHelper
+  * @Description:    创建和升级数据库
+ */
+public class NotesDatabaseHelper extends SQLiteOpenHelper {
+    private static final String DB_NAME = "note.db";
+
+    private static final int DB_VERSION = 4;
+
+    public interface TABLE {
+        public static final String NOTE = "note";
+
+        public static final String DATA = "data";
+    }
+
+    private static final String TAG = "NotesDatabaseHelper";
+
+    private static NotesDatabaseHelper mInstance;
+
+    /**创建note表的sql语句
+     * note表：存储便签与文件夹的信息
+     */
+    private static final String CREATE_NOTE_TABLE_SQL =
+        "CREATE TABLE " + TABLE.NOTE + "(" +
+            NoteColumns.ID + " INTEGER PRIMARY KEY," +
+            NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +
+            NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +
+            NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
+            NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
+        ")";
+
+    /**创建data表的sql语句
+     * data表：保存具体的数据条目
+     */
+    private static final String CREATE_DATA_TABLE_SQL =
+        "CREATE TABLE " + TABLE.DATA + "(" +
+            DataColumns.ID + " INTEGER PRIMARY KEY," +
+            DataColumns.MIME_TYPE + " TEXT NOT NULL," +
+            DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA1 + " INTEGER," +
+            DataColumns.DATA2 + " INTEGER," +
+            DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
+        ")";
+
+    //为data表的note_id列创建索引的sql语句：
+    private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
+        "CREATE INDEX IF NOT EXISTS note_id_index ON " +
+        TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
+
+    /**
+     * Increase folder's note count when move note to the folder
+     * 创建触发器increase_folder_count_on_update：
+     * 触发时机：事件后
+     * 触发事件：当note表内PARENT_ID更新
+     * 触发器动作：更新note表中对应父文件夹的计数
+     */
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+        "CREATE TRIGGER increase_folder_count_on_update "+
+        " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+        "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+        " END";
+
+    /**
+     * Decrease folder's note count when move note from folder
+     * 创建触发器decrease_folder_count_on_update：
+     * 触发时机：事件后
+     * 触发事件：当note表内PARENT_ID更新
+     * 触发器动作：更新note表中对应原父文件夹的计数
+     */
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+        "CREATE TRIGGER decrease_folder_count_on_update " +
+        " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+        "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+        "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
+        " END";
+
+    /**
+     * Increase folder's note count when insert new note to the folder
+     * 创建触发器increase_folder_count_on_insert：
+     * 触发时机：事件后
+     * 触发事件：当note表内插入新一行
+     * 触发器动作：更新note表中对应父文件夹的计数
+     */
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
+        "CREATE TRIGGER increase_folder_count_on_insert " +
+        " AFTER INSERT ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+        "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+        " END";
+
+    /**
+     * Decrease folder's note count when delete note from the folder
+     * 创建触发器decrease_folder_count_on_delete：
+     * 触发时机：事件后
+     * 触发事件：当note表内删除记录
+     * 触发器动作：更新note表中对应原父文件夹的计数
+     */
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER decrease_folder_count_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+        "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+        "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
+        " END";
+
+    /**
+     * Update note's content when insert data with type {@link DataConstants#NOTE}
+     * 创建触发器update_note_content_on_insert：
+     * 触发时机：事件后
+     * 触发事件：data表中新插入了某一行（该表数据类型是文字便签类）
+     * 触发动作：更新对应的note表中的摘要为新便签的内容
+     */
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
+        "CREATE TRIGGER update_note_content_on_insert " +
+        " AFTER INSERT ON " + TABLE.DATA +
+        " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+        "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    /**
+     * Update note's content when data with {@link DataConstants#NOTE} type has changed
+     * 创建触发器update_note_content_on_update：
+     * 触发时机：事件后
+     * 触发事件：当data表内更新记录（该表数据类型是文字便签类）
+     * 触发器动作：更新note表中对应便签的摘要内容为新内容
+     */
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
+        "CREATE TRIGGER update_note_content_on_update " +
+        " AFTER UPDATE ON " + TABLE.DATA +
+        " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+        "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    /**
+     * Update note's content when data with {@link DataConstants#NOTE} type has deleted
+     * 创建触发器update_note_content_on_delete：
+     * 触发时机：事件后
+     * 触发事件：当data表内删除记录
+     * 触发器动作：更新note表中对应便签的摘要内容为空
+     */
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER update_note_content_on_delete " +
+        " AFTER delete ON " + TABLE.DATA +
+        " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=''" +
+        "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    /**
+     * Delete datas belong to note which has been deleted
+     * 创建触发器delete_data_on_delete：
+     * 触发时机：事件后
+     * 触发事件：当note表内删除记录
+     * 触发器动作：删除data表中对应便签的所有数据
+     */
+    private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER delete_data_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN" +
+        "  DELETE FROM " + TABLE.DATA +
+        "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    /**
+     * Delete notes belong to folder which has been deleted
+     * 创建触发器folder_delete_notes_on_delete：
+     * 触发时机：事件后
+     * 触发事件：当note表内删除文件夹记录
+     * 触发器动作：删除note表中对应父文件夹的所有便签
+     */
+    private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
+        "CREATE TRIGGER folder_delete_notes_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN" +
+        "  DELETE FROM " + TABLE.NOTE +
+        "   WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    /**
+     * Move notes belong to folder which has been moved to trash folder
+     * 创建触发器folder_move_notes_on_trash：
+     * 触发时机：事件后
+     * 触发事件：当note表内PARENT_ID更新为垃圾文件夹id
+     * 触发器动作：更新note表中对应原父文件夹的所有便签的父id为垃圾文件夹id
+     */
+    private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
+        "CREATE TRIGGER folder_move_notes_on_trash " +
+        " AFTER UPDATE ON " + TABLE.NOTE +
+        " WHEN new." + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+        "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+
+    /**
+     * @method  NotesDatabaseHelper
+     * @description 调用父类构造函数
+     * @param   context  上下文
+     * 上下文：   context
+     * 数据库名字：DB_NAME
+     * 游标工厂： 默认
+     * 数据库版本号：DB_VERSION
+     */
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+
+
+     //创建note表
+    public void createNoteTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
+        Log.d(TAG, "note table has been created");
+    }
+
+    //创建note表触发器
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        //将已有的触发器删掉
+        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
+        db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
+        db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert");
+        db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
+
+        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
+        db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
+        db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER);
+        db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER);
+        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER);
+        db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER);
+        db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
+    }
+
+    //创建系统文件夹
+    private void createSystemFolder(SQLiteDatabase db) {
+        //ContentValues是一个键值对集合，用于存储一行数据。名是string，值为基本类型。
+        ContentValues values = new ContentValues();
+        /**
+         * call record foler for call notes
+         * 创建通话记录文件夹
+         */
+        values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        /**
+         * root folder which is default folder
+         * 创建默认文件夹
+         */
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        /**
+         * temporary folder which is used for moving note
+         * 创建临时文件夹（存储不属于其他文件夹的便签）
+         */
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        /**
+         * create trash folder
+         * 创建垃圾文件夹
+         */
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+    //创建data表
+    public void createDataTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_DATA_TABLE_SQL);
+        reCreateDataTableTriggers(db);
+        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
+        Log.d(TAG, "data table has been created");
+    }
+
+    //创建data表触发器
+    private void reCreateDataTableTriggers(SQLiteDatabase db) {
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete");
+
+        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER);
+        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER);
+        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER);
+    }
+
+    //创建NotesDatabaseHelper的单例
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    //重写onCreate方法：创建数据库
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    /**
+     * @method  onUpgrade
+     * @description 数据库升级
+     * @param db 数据库
+     * @param oldVersion 旧版本
+     * @param newVersion 新版本
+     */
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
+
+        if (oldVersion == 1) {
+            upgradeToV2(db);
+            skipV2 = true; // this upgrade including the upgrade from v2 to v3 v1->v2升级已包含v2->v3升级
+            oldVersion++;
+        }
+
+        if (oldVersion == 2 && !skipV2) {
+            upgradeToV3(db);
+            reCreateTriggers = true;
+            oldVersion++;
+        }
+
+        if (oldVersion == 3) {
+            upgradeToV4(db);
+            oldVersion++;
+        }
+
+        if (reCreateTriggers) {
+            reCreateNoteTableTriggers(db);
+            reCreateDataTableTriggers(db);
+        }
+
+        if (oldVersion != newVersion) {
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+    //更新到版本2：重建note表和data表
+    private void upgradeToV2(SQLiteDatabase db) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    //更新到版本3：引入Gtask功能，添加垃圾站功能
+    private void upgradeToV3(SQLiteDatabase db) {
+        // drop unused triggers
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_delete");
+        db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_update");
+        // add a column for gtask id
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // add a trash system folder
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+    //更新到版本4：增加版本字段
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}

src/data/NotesProvider.java

@@ -0,0 +1,380 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+
+import android.app.SearchManager;
+import android.content.ContentProvider;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.NotesDatabaseHelper.TABLE;
+
+/**     
+  * 
+  * @Package:        net.micode.notes.data
+  * @ClassName:      NotesProvider
+  * @Description:    便签提供类 
+ */
+public class NotesProvider extends ContentProvider {
+    //uri匹配器
+    private static final UriMatcher mMatcher;
+
+    private NotesDatabaseHelper mHelper;
+
+    private static final String TAG = "NotesProvider";
+
+    //定义便签、数据相关的uri常量
+    private static final int URI_NOTE            = 1;
+    private static final int URI_NOTE_ITEM       = 2;
+    private static final int URI_DATA            = 3;
+    private static final int URI_DATA_ITEM       = 4;
+
+    //定义搜索相关的uri常量
+    private static final int URI_SEARCH          = 5;
+    private static final int URI_SEARCH_SUGGEST  = 6;
+
+
+     //初始化并配置 UriMatcher 实例。将 URI 模式映射到整数值。
+    static {
+        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);//# 表示数字占位符，匹配特定 ID
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);//# 表示数字占位符，匹配特定 ID
+        mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
+         //两个搜索建议的URI模式：一个是基本的搜索建议请求，另一个是带有查询字符串的搜索建议请求
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);//*表示任意字符
+    }
+
+    /**
+     * x'0A' represents the '\n' character in sqlite. For title and content in the search result,
+     * we will trim '\n' and white space in order to show more information.
+     * 定义了一个用于搜索的字符串。
+     */
+    private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
+        + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","
+            //将摘要中的换行符替换为空字符串后，去除两端空字符，作为搜索结果的主文本
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+            //与主文本内容一致
+        + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+            //资源里的图片作为指定搜索结果的图标
+        + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+            //显示用户的数据 作为 点击搜索结果时要执行的动作
+        + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
+            //文本数据类型 作为 指定内容的 MIME 类型
+
+    //定义了一个用于根据内容摘要进行搜索的SQL查询语句。
+    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+        + " FROM " + TABLE.NOTE
+        + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
+            //"?"是占位符，在查找时，将传入搜索的内容
+        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+            //不搜索垃圾文件夹中便签
+        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+            //只搜索普通便签
+
+    //创建NotesDatabaseHelper实例
+    @Override
+    public boolean onCreate() {
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+    /**
+     * @method  query
+     * @description 查询数据的方法，根据传入的URI和其他参数，从数据库中检索相应的数据.
+     * @param [uri, projection, selection, selectionArgs, sortOrder]
+     * @return android.database.Cursor
+     */
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+            String sortOrder) {
+        Cursor c = null;
+        SQLiteDatabase db = mHelper.getReadableDatabase();
+        String id = null;
+        switch (mMatcher.match(uri)) { //根据返回的匹配码执行相应操作
+            case URI_NOTE:
+                //查Note表中的内容
+                c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);//获取便签id
+                //构建查询条件，确保只查询指定ID
+                c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_DATA:
+                //查询数据表中的数据
+                c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_SEARCH:
+            case URI_SEARCH_SUGGEST:
+                if (sortOrder != null || projection != null) {
+                    //搜索查询不允许指定排序顺序或投影
+                    throw new IllegalArgumentException(
+                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                }
+
+                String searchString = null;
+                //从URI中提取搜索字符串
+                if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
+                    if (uri.getPathSegments().size() > 1) {
+                        searchString = uri.getPathSegments().get(1);
+                    }
+                } else {
+                    searchString = uri.getQueryParameter("pattern");
+                }
+
+                if (TextUtils.isEmpty(searchString)) {
+                    return null;
+                }
+
+                try {
+                    searchString = String.format("%%%s%%", searchString);//用于模糊匹配的SQL通配符
+                    //执行预定义的 SQL 查询语句，传入搜索字符串作为参数
+                    c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
+                            new String[] { searchString });
+                } catch (IllegalStateException ex) {
+                    Log.e(TAG, "got exception: " + ex.toString());
+                }
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        //设置通知URI，以便在数据更改时通知观察者（不懂）
+        if (c != null) {
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+
+    /**
+     * @method  insert
+     * @description 插入数据的方法，根据传入的URI和ContentValues，将数据插入到数据库中。
+     * @param [uri, values]
+     * @return android.net.Uri 新插入数据的URI
+     */
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        long dataId = 0, noteId = 0, insertedId = 0;
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                insertedId = noteId = db.insert(TABLE.NOTE, null, values);//插入新的记录
+                break;
+            case URI_DATA:
+                //确保数据关联的ID有效
+                if (values.containsKey(DataColumns.NOTE_ID)) {
+                    noteId = values.getAsLong(DataColumns.NOTE_ID);
+                } else {
+                    Log.d(TAG, "Wrong data format without note id:" + values.toString());
+                }
+                insertedId = dataId = db.insert(TABLE.DATA, null, values);//插入新的数据记录
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        // Notify the note uri 通知相关的URI，表示数据已更改
+        if (noteId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+        // Notify the data uri 通知相关的数据URI，表示数据已更改
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+        return ContentUris.withAppendedId(uri, insertedId); //返回新插入的URI
+    }
+
+    /**
+     * @method  delete
+     * @description 删除
+     * @param [uri, selection, selectionArgs]
+     * @return int
+     */
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        boolean deleteData = false;
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";//确保不删除系统文件夹
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);//删除相关便签，返回删除的记录数
+                break;
+            case URI_NOTE_ITEM:
+                //获取要删除的id
+                id = uri.getPathSegments().get(1);
+                /**
+                 * ID that smaller than 0 is system folder which is not allowed to
+                 * trash
+                 */
+                long noteId = Long.valueOf(id);
+                if (noteId <= 0) {
+                    break;
+                }
+                count = db.delete(TABLE.NOTE,
+                        NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                break;
+            case URI_DATA:
+                count = db.delete(TABLE.DATA, selection, selectionArgs);
+                deleteData = true;
+                break;
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                count = db.delete(TABLE.DATA,
+                        DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                deleteData = true;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (count > 0) {
+            //如果删除了data记录，通知相关的note URI
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            //通知传入的URI，表示数据已更改
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    /**
+     * @method  update
+     * @description 更新数据库中的记录
+     * @param [uri, values, selection, selectionArgs]
+     * @return int 影响的行数
+     */
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        boolean updateData = false;
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                increaseNoteVersion(-1, selection, selectionArgs);//更新便签版本号
+                count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                break;
+            case URI_DATA:
+                count = db.update(TABLE.DATA, values, selection, selectionArgs);
+                updateData = true;
+                break;
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                updateData = true;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+
+        if (count > 0) {
+            if (updateData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);//通知便签URI数据已更改
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    /**
+     * @method  parseSelection
+     * @description //辅助方法，用于解析查询条件字符串，确保在已有条件的基础上正确添加新的条件。
+     * @param selection
+     * @return String
+     */
+    private String parseSelection(String selection) {
+        //如果selection不为空，则在前面加上" AND ("，并在后面加上")"，否则返回空字符串
+        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+    }
+
+    /**
+     * @method  increaseNoteVersion
+     * @description  增加便签的版本号，用于标识便签的更新状态。
+     * @param
+     * @return
+     */
+    private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+        StringBuilder sql = new StringBuilder(120);//初始化一个容量为120的StringBuilder对象，用于构建SQL语句
+        //构建更新便签版本号的SQL语句
+        sql.append("UPDATE ");
+        sql.append(TABLE.NOTE);
+        sql.append(" SET ");
+        sql.append(NoteColumns.VERSION);
+        sql.append("=" + NoteColumns.VERSION + "+1 ");
+
+        //如果指定了id或selection，则添加WHERE子句
+        if (id > 0 || !TextUtils.isEmpty(selection)) {
+            sql.append(" WHERE ");
+        }
+        //如果指定了id，则添加ID条件
+        if (id > 0) {
+            sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+        }
+
+        if (!TextUtils.isEmpty(selection)) {
+            String selectString = id > 0 ? parseSelection(selection) : selection;
+            for (String args : selectionArgs) {
+                selectString = selectString.replaceFirst("\\?", args);//将每个占位符 '?' 替换为实际的参数值
+            }
+            sql.append(selectString);
+        }
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());//执行构建好的SQL语句
+    }
+
+    //未实现：获取URI对应的MIME类型
+    @Override
+    public String getType(Uri uri) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

src/gtask/data/MetaData.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+
+/**
+  * @Package:        net.micode.notes.gtask.data
+  * @ClassName:      MetaData
+  * @Description:    存储和管理Google Task同步相关的元数据，维护本地便签与Google Task任务的关联关系
+ */
+public class MetaData extends Task {
+    private final static String TAG = MetaData.class.getSimpleName();
+
+    private String mRelatedGid = null;
+
+    public void setMeta(String gid, JSONObject metaInfo) {
+        try {
+            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
+        } catch (JSONException e) {
+            Log.e(TAG, "failed to put related gid");
+        }
+        setNotes(metaInfo.toString());
+        setName(GTaskStringUtils.META_NOTE_NAME);
+    }
+
+    public String getRelatedGid() {
+        return mRelatedGid;
+    }
+
+    @Override
+    public boolean isWorthSaving() {
+        return getNotes() != null;
+    }//只要便签非空，就认为值得保存
+
+    @Override
+    public void setContentByRemoteJSON(JSONObject js) {
+        super.setContentByRemoteJSON(js);
+        if (getNotes() != null) {
+            try {
+                JSONObject metaInfo = new JSONObject(getNotes().trim());
+                mRelatedGid = metaInfo.getString(GTaskStringUtils.META_HEAD_GTASK_ID);
+            } catch (JSONException e) {
+                Log.w(TAG, "failed to get related gid");
+                mRelatedGid = null;
+            }
+        }
+    }
+
+    @Override
+    public void setContentByLocalJSON(JSONObject js) {
+        // this function should not be called
+        //功能是被禁止调用的，因为元数据不从本地 JSON 设置内容
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+    }
+
+    @Override
+    public JSONObject getLocalJSONFromContent() {
+        //功能是被禁止调用的，因为元数据不生成本地 JSON 内容
+        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
+    }
+
+    @Override
+    public int getSyncAction(Cursor c) {
+        //功能是被禁止调用的，因为元数据不参与同步操作
+        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
+    }
+
+}

src/gtask/data/Node.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+
+
+import org.json.JSONObject;
+
+/**
+  *
+  * @Package:        net.micode.notes.gtask.data
+  * @ClassName:      Node
+  * @Description:    抽象类，表示同步节点的基本属性和行为。
+ */
+public abstract class Node {
+    //同步操作类型常量定义
+    public static final int SYNC_ACTION_NONE = 0;
+
+    public static final int SYNC_ACTION_ADD_REMOTE = 1;
+
+    public static final int SYNC_ACTION_ADD_LOCAL = 2;
+
+    public static final int SYNC_ACTION_DEL_REMOTE = 3;
+
+    public static final int SYNC_ACTION_DEL_LOCAL = 4;
+
+    public static final int SYNC_ACTION_UPDATE_REMOTE = 5;
+
+    public static final int SYNC_ACTION_UPDATE_LOCAL = 6;
+
+    public static final int SYNC_ACTION_UPDATE_CONFLICT = 7;
+
+    public static final int SYNC_ACTION_ERROR = 8;
+
+    // 节点的全局唯一标识符
+    private String mGid;
+
+    private String mName;
+
+    private long mLastModified;
+
+    private boolean mDeleted;
+
+    // 构造函数，初始化节点的基本属性
+    public Node() {
+        mGid = null;
+        mName = "";
+        mLastModified = 0;
+        mDeleted = false;
+    }
+
+    /**
+     * 定义了一些方法:创建节点的远程和本地同步操作的 JSON 表示
+     * 从远程和本地 JSON 设置节点内容
+     * 从数据库游标获取同步操作类型
+     * 以及节点属性的 get和 set 方法
+     */
+
+
+    public abstract JSONObject getCreateAction(int actionId);//
+
+    public abstract JSONObject getUpdateAction(int actionId);
+
+    public abstract void setContentByRemoteJSON(JSONObject js);
+
+    public abstract void setContentByLocalJSON(JSONObject js);
+
+    public abstract JSONObject getLocalJSONFromContent();
+
+    public abstract int getSyncAction(Cursor c);
+
+    public void setGid(String gid) {
+        this.mGid = gid;
+    }
+
+    public void setName(String name) {
+        this.mName = name;
+    }
+
+    public void setLastModified(long lastModified) {
+        this.mLastModified = lastModified;
+    }
+
+    public void setDeleted(boolean deleted) {
+        this.mDeleted = deleted;
+    }
+
+    public String getGid() {
+        return this.mGid;
+    }
+
+    public String getName() {
+        return this.mName;
+    }
+
+    public long getLastModified() {
+        return this.mLastModified;
+    }
+
+    public boolean getDeleted() {
+        return this.mDeleted;
+    }
+
+}

src/gtask/data/SqlData.java

@@ -0,0 +1,226 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.NotesDatabaseHelper.TABLE;
+import net.micode.notes.gtask.exception.ActionFailureException;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**     
+  * 
+  * @Package:        net.micode.notes.gtask.data
+  * @ClassName:      SqlData
+  * @Description:     为Google Task同步功能提供数据层支持，将便签数据抽象为可序列化的对象
+ */
+public class SqlData {
+    private static final String TAG = SqlData.class.getSimpleName();
+
+    private static final int INVALID_ID = -99999;
+
+    //包含便签数据表的核心字段，用于查询和加载数据
+    public static final String[] PROJECTION_DATA = new String[] {
+            DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1,
+            DataColumns.DATA3
+    };
+
+    // 查询结果列索引常量，提高代码可读性和维护性
+    public static final int DATA_ID_COLUMN = 0;
+
+    public static final int DATA_MIME_TYPE_COLUMN = 1;
+
+    public static final int DATA_CONTENT_COLUMN = 2;
+
+    public static final int DATA_CONTENT_DATA_1_COLUMN = 3;
+
+    public static final int DATA_CONTENT_DATA_3_COLUMN = 4;
+
+    private ContentResolver mContentResolver;
+
+    private boolean mIsCreate;// 标记是否为新建数据
+
+    private long mDataId;
+
+    private String mDataMimeType;
+
+    private String mDataContent;
+
+    private long mDataContentData1;
+
+    private String mDataContentData3;
+
+    private ContentValues mDiffDataValues;// 存储数据变化的ContentValues
+
+    //构造函数：新建便签
+    public SqlData(Context context) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;
+        mDataId = INVALID_ID;
+        mDataMimeType = DataConstants.NOTE;
+        mDataContent = "";// 初始内容为空
+        mDataContentData1 = 0;
+        mDataContentData3 = "";
+        mDiffDataValues = new ContentValues();
+    }
+
+    //构造函数：从数据库游标加载现有数据
+    public SqlData(Context context, Cursor c) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(c);
+        mDiffDataValues = new ContentValues();
+    }
+
+    //从数据库游标加载数据到对象字段
+    private void loadFromCursor(Cursor c) {
+        mDataId = c.getLong(DATA_ID_COLUMN);
+        mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN);
+        mDataContent = c.getString(DATA_CONTENT_COLUMN);
+        mDataContentData1 = c.getLong(DATA_CONTENT_DATA_1_COLUMN);
+        mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN);
+    }
+
+    //将JSON格式的数据解析并设置到对象字段
+    public void setContent(JSONObject js) throws JSONException {
+        // 处理数据ID
+        long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID;//如果有ID字段则取值，否则设为无效ID
+        if (mIsCreate || mDataId != dataId) {
+            mDiffDataValues.put(DataColumns.ID, dataId);
+        }//如果是新建数据或ID发生变化，记录变化
+        mDataId = dataId;
+
+        //处理MIME类型
+        String dataMimeType = js.has(DataColumns.MIME_TYPE) ? js.getString(DataColumns.MIME_TYPE)
+                : DataConstants.NOTE;
+        if (mIsCreate || !mDataMimeType.equals(dataMimeType)) {
+            mDiffDataValues.put(DataColumns.MIME_TYPE, dataMimeType);
+        }
+        mDataMimeType = dataMimeType;
+
+        //处理数据内容
+        String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : "";
+        if (mIsCreate || !mDataContent.equals(dataContent)) {
+            mDiffDataValues.put(DataColumns.CONTENT, dataContent);
+        }
+        mDataContent = dataContent;
+
+        //处理扩展数据1
+        long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0;
+        if (mIsCreate || mDataContentData1 != dataContentData1) {
+            mDiffDataValues.put(DataColumns.DATA1, dataContentData1);
+        }
+        mDataContentData1 = dataContentData1;
+
+        // 处理扩展数据3
+        String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : "";
+        if (mIsCreate || !mDataContentData3.equals(dataContentData3)) {
+            mDiffDataValues.put(DataColumns.DATA3, dataContentData3);
+        }
+        mDataContentData3 = dataContentData3;
+    }
+
+    //将对象字段序列化为JSON格式，用于网络传输或数据交换
+    public JSONObject getContent() throws JSONException {
+        if (mIsCreate) {
+            Log.e(TAG, "it seems that we haven't created this in database yet");
+            return null;
+        }
+        JSONObject js = new JSONObject();
+        js.put(DataColumns.ID, mDataId);
+        js.put(DataColumns.MIME_TYPE, mDataMimeType);
+        js.put(DataColumns.CONTENT, mDataContent);
+        js.put(DataColumns.DATA1, mDataContentData1);
+        js.put(DataColumns.DATA3, mDataContentData3);
+        return js;
+    }
+
+    /**
+     * @method  commit
+     * @description 提交数据到数据库
+     * 执行流程：
+     *     1. 新数据：执行INSERT操作，插入后从URI中提取新数据的ID
+     *     2. 现有数据：执行UPDATE操作，支持版本验证
+     *     3. 清除变更记录，更新对象状态
+     * @param noteId 关联的便签ID
+     * @param validateVersion 是否验证版本号
+     * @param version 期望的版本号
+     */
+    public void commit(long noteId, boolean validateVersion, long version) {
+        // 新数据：执行INSERT操作
+        if (mIsCreate) {
+            // 如果ID是无效值，从变更记录中移除ID字段
+            if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) {
+                mDiffDataValues.remove(DataColumns.ID);
+            }
+
+            // 设置关联的便签ID
+            mDiffDataValues.put(DataColumns.NOTE_ID, noteId);
+
+            // 执行插入操作
+            Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues);
+
+            try {
+                mDataId = Long.valueOf(uri.getPathSegments().get(1));//从返回的URI中提取新数据的ID
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString());
+                throw new ActionFailureException("create note failed");
+            }
+        }
+        //现有数据：执行UPDATE操作
+        else {
+            if (mDiffDataValues.size() > 0) {
+                int result = 0;
+                if (!validateVersion) {
+                    // 不验证版本：直接更新
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null);
+                } else {
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues,
+                            " ? in (SELECT " + NoteColumns.ID + " FROM " + TABLE.NOTE
+                                    + " WHERE " + NoteColumns.VERSION + "=?)", new String[] {
+                                    String.valueOf(noteId), String.valueOf(version)
+                            });
+                }
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
+                }
+            }
+        }
+
+        // 清除变更记录，更新对象状态
+        mDiffDataValues.clear();
+        mIsCreate = false;
+    }
+
+    public long getId() {
+        return mDataId;
+    }
+}

src/gtask/data/SqlNote.java

@@ -0,0 +1,585 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+import net.micode.notes.tool.ResourceParser;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+
+
+/**
+  *
+  * @Package:        net.micode.notes.gtask.data
+  * @ClassName:      SqlNote
+  * @Description:    管理便签的所有属性、数据和关联关系
+ */
+public class SqlNote {
+    private static final String TAG = SqlNote.class.getSimpleName();  // 日志标签
+
+    private static final int INVALID_ID = -99999;  // 无效ID常量，表示便签尚未保存到数据库
+
+    //便签表的所有字段，用于查询和加载便签
+    public static final String[] PROJECTION_NOTE = new String[] {
+            NoteColumns.ID,                 // 便签ID
+            NoteColumns.ALERTED_DATE,       // 提醒日期
+            NoteColumns.BG_COLOR_ID,        // 背景颜色ID
+            NoteColumns.CREATED_DATE,       // 创建日期
+            NoteColumns.HAS_ATTACHMENT,     // 是否有附件
+            NoteColumns.MODIFIED_DATE,      // 修改日期
+            NoteColumns.NOTES_COUNT,        // 子便签数量
+            NoteColumns.PARENT_ID,          // 父文件夹ID
+            NoteColumns.SNIPPET,            // 片段内容
+            NoteColumns.TYPE,               // 便签类型
+            NoteColumns.WIDGET_ID,          // 小部件ID
+            NoteColumns.WIDGET_TYPE,        // 小部件类型
+            NoteColumns.SYNC_ID,            // 同步ID
+            NoteColumns.LOCAL_MODIFIED,     // 本地修改标记
+            NoteColumns.ORIGIN_PARENT_ID,   // 原始父文件夹ID
+            NoteColumns.GTASK_ID,           // Google Task ID
+            NoteColumns.VERSION             // 版本号
+    };
+
+    // 查询结果列索引常量
+    public static final int ID_COLUMN = 0;
+    public static final int ALERTED_DATE_COLUMN = 1;
+    public static final int BG_COLOR_ID_COLUMN = 2;
+    public static final int CREATED_DATE_COLUMN = 3;
+    public static final int HAS_ATTACHMENT_COLUMN = 4;
+    public static final int MODIFIED_DATE_COLUMN = 5;
+    public static final int NOTES_COUNT_COLUMN = 6;
+    public static final int PARENT_ID_COLUMN = 7;
+    public static final int SNIPPET_COLUMN = 8;
+    public static final int TYPE_COLUMN = 9;
+    public static final int WIDGET_ID_COLUMN = 10;
+    public static final int WIDGET_TYPE_COLUMN = 11;
+    public static final int SYNC_ID_COLUMN = 12;
+    public static final int LOCAL_MODIFIED_COLUMN = 13;
+    public static final int ORIGIN_PARENT_ID_COLUMN = 14;
+    public static final int GTASK_ID_COLUMN = 15;
+    public static final int VERSION_COLUMN = 16;
+
+    private Context mContext;                // Android上下文
+    private ContentResolver mContentResolver; // ContentResolver，用于数据库操作
+    private boolean mIsCreate;               // 标记是否为新建便签
+    private long mId;
+    private long mAlertDate;
+    private int mBgColorId;
+    private long mCreatedDate;
+    private int mHasAttachment;              // 是否有附件（0无，1有）
+    private long mModifiedDate;
+    private long mParentId;                  // 父文件夹ID
+    private String mSnippet;                 // 摘要
+    private int mType;                       // 便签类型（NOTE/FOLDER/SYSTEM）
+    private int mWidgetId;
+    private int mWidgetType;
+    private long mOriginParent;              // 原始父文件夹ID（用于恢复操作）
+    private long mVersion;                   // 版本号
+
+    private ContentValues mDiffNoteValues;   // 存储便签变化的ContentValues
+    private ArrayList<SqlData> mDataList;    // 关联的数据列表（仅TYPE_NOTE类型）
+
+    //构造函数：创建新便签
+    public SqlNote(Context context) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;
+        mId = INVALID_ID;                              // 新便签ID无效
+        mAlertDate = 0;                                // 默认无提醒
+        mBgColorId = ResourceParser.getDefaultBgId(context);
+        mCreatedDate = System.currentTimeMillis();
+        mHasAttachment = 0;
+        mModifiedDate = System.currentTimeMillis();
+        mParentId = 0;                                 // 默认父文件夹为根目录
+        mSnippet = "";                                 // 默认摘要内容为空
+        mType = Notes.TYPE_NOTE;                       // 默认为普通便签
+        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
+        mOriginParent = 0;
+        mVersion = 0;
+        mDiffNoteValues = new ContentValues();
+        mDataList = new ArrayList<SqlData>();
+    }
+
+    //构造函数：从数据库游标加载现有便签
+    public SqlNote(Context context, Cursor c) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(c);
+        mDataList = new ArrayList<SqlData>(); // 初始化数据列表
+        if (mType == Notes.TYPE_NOTE)         // 如果是普通便签，加载数据内容
+            loadDataContent();
+        mDiffNoteValues = new ContentValues(); // 初始化变化值容器
+    }
+
+    //构造函数：根据便签ID加载现有便签
+    public SqlNote(Context context, long id) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(id);                   // 根据ID加载便签
+        mDataList = new ArrayList<SqlData>();
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues();
+    }
+
+
+    //根据便签ID从数据库加载便签
+    private void loadFromCursor(long id) {
+        Cursor c = null;
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
+                    new String[] {
+                            String.valueOf(id)
+                    }, null);
+            if (c != null) {
+                c.moveToNext();
+                loadFromCursor(c);
+            } else {
+                Log.w(TAG, "loadFromCursor: cursor = null");
+            }
+        } finally {
+            if (c != null)
+                c.close();  // 关闭游标
+        }
+    }
+
+    //从数据库游标加载便签属性
+    private void loadFromCursor(Cursor c) {
+        mId = c.getLong(ID_COLUMN);
+        mAlertDate = c.getLong(ALERTED_DATE_COLUMN);
+        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN);
+        mCreatedDate = c.getLong(CREATED_DATE_COLUMN);
+        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN);
+        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN);
+        mParentId = c.getLong(PARENT_ID_COLUMN);
+        mSnippet = c.getString(SNIPPET_COLUMN);
+        mType = c.getInt(TYPE_COLUMN);
+        mWidgetId = c.getInt(WIDGET_ID_COLUMN);
+        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN);
+        mVersion = c.getLong(VERSION_COLUMN);
+    }
+
+    /**
+     * 加载便签关联的数据内容
+     * 执行流程：
+     * 1. 根据便签ID查询数据表
+     * 2. 遍历查询结果，创建SqlData对象
+     * 3. 将SqlData对象添加到数据列表
+     */
+    private void loadDataContent() {
+        Cursor c = null;
+        mDataList.clear();  // 清空现有数据列表
+        try {
+            c = mContentResolver.query(Notes.CONTENT_DATA_URI, SqlData.PROJECTION_DATA,
+                    "(note_id=?)", new String[] {
+                            String.valueOf(mId)
+                    }, null);
+            if (c != null) {
+                if (c.getCount() == 0) {
+                    Log.w(TAG, "it seems that the note has not data");
+                    return;
+                }
+                while (c.moveToNext()) {
+                    SqlData data = new SqlData(mContext, c);
+                    mDataList.add(data);
+                }
+            } else {
+                Log.w(TAG, "loadDataContent: cursor = null");
+            }
+        } finally {
+            if (c != null)
+                c.close();
+        }
+    }
+
+    /**
+     * @method  setContent
+     * @description 功能：将JSON格式的便签数据解析并设置到对象字段
+     *              执行流程：
+     *               1. 提取便签元数据部分
+     *               2. 根据便签类型分别处理
+     *               3. 记录哪些字段发生了变化，用于后续的增量更新
+     * @param js 包含便签信息的JSON对象
+     * @return
+     */
+    public boolean setContent(JSONObject js) {
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+
+            // 系统文件夹：不能设置
+            if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                Log.w(TAG, "cannot set system folder");
+            }
+            // 文件夹：只能更新片段和类型
+            else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                // 处理片段内容
+                String snippet = note.has(NoteColumns.SNIPPET) ? note
+                        .getString(NoteColumns.SNIPPET) : "";
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+
+                // 处理类型
+                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE;
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+            }
+            // 普通便签：处理所有字段
+            else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_NOTE) {
+                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+                // 处理便签ID
+                long id = note.has(NoteColumns.ID) ? note.getLong(NoteColumns.ID) : INVALID_ID;
+                if (mIsCreate || mId != id) {
+                    mDiffNoteValues.put(NoteColumns.ID, id);
+                }
+                mId = id;
+
+                // 处理提醒日期
+                long alertDate = note.has(NoteColumns.ALERTED_DATE) ? note
+                        .getLong(NoteColumns.ALERTED_DATE) : 0;
+                if (mIsCreate || mAlertDate != alertDate) {
+                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate);
+                }
+                mAlertDate = alertDate;
+
+                // 处理背景颜色ID
+                int bgColorId = note.has(NoteColumns.BG_COLOR_ID) ? note
+                        .getInt(NoteColumns.BG_COLOR_ID) : ResourceParser.getDefaultBgId(mContext);
+                if (mIsCreate || mBgColorId != bgColorId) {
+                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId);
+                }
+                mBgColorId = bgColorId;
+
+                // 处理创建日期
+                long createDate = note.has(NoteColumns.CREATED_DATE) ? note
+                        .getLong(NoteColumns.CREATED_DATE) : System.currentTimeMillis();
+                if (mIsCreate || mCreatedDate != createDate) {
+                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate);
+                }
+                mCreatedDate = createDate;
+
+                // 处理附件标记
+                int hasAttachment = note.has(NoteColumns.HAS_ATTACHMENT) ? note
+                        .getInt(NoteColumns.HAS_ATTACHMENT) : 0;
+                if (mIsCreate || mHasAttachment != hasAttachment) {
+                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment);
+                }
+                mHasAttachment = hasAttachment;
+
+                // 处理修改日期
+                long modifiedDate = note.has(NoteColumns.MODIFIED_DATE) ? note
+                        .getLong(NoteColumns.MODIFIED_DATE) : System.currentTimeMillis();
+                if (mIsCreate || mModifiedDate != modifiedDate) {
+                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate);
+                }
+                mModifiedDate = modifiedDate;
+
+                // 处理父文件夹ID
+                long parentId = note.has(NoteColumns.PARENT_ID) ? note
+                        .getLong(NoteColumns.PARENT_ID) : 0;
+                if (mIsCreate || mParentId != parentId) {
+                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId);
+                }
+                mParentId = parentId;
+
+                // 处理片段内容
+                String snippet = note.has(NoteColumns.SNIPPET) ? note
+                        .getString(NoteColumns.SNIPPET) : "";
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+
+                // 处理类型
+                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE;
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+
+                // 处理小部件ID
+                int widgetId = note.has(NoteColumns.WIDGET_ID) ? note.getInt(NoteColumns.WIDGET_ID)
+                        : AppWidgetManager.INVALID_APPWIDGET_ID;
+                if (mIsCreate || mWidgetId != widgetId) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId);
+                }
+                mWidgetId = widgetId;
+
+                // 处理小部件类型
+                int widgetType = note.has(NoteColumns.WIDGET_TYPE) ? note
+                        .getInt(NoteColumns.WIDGET_TYPE) : Notes.TYPE_WIDGET_INVALIDE;
+                if (mIsCreate || mWidgetType != widgetType) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType);
+                }
+                mWidgetType = widgetType;
+
+                // 处理原始父文件夹ID
+                long originParent = note.has(NoteColumns.ORIGIN_PARENT_ID) ? note
+                        .getLong(NoteColumns.ORIGIN_PARENT_ID) : 0;
+                if (mIsCreate || mOriginParent != originParent) {
+                    mDiffNoteValues.put(NoteColumns.ORIGIN_PARENT_ID, originParent);
+                }
+                mOriginParent = originParent;
+
+                // 处理数据内容
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    SqlData sqlData = null;
+
+                    // 查找现有的数据对象
+                    if (data.has(DataColumns.ID)) {
+                        long dataId = data.getLong(DataColumns.ID);
+                        for (SqlData temp : mDataList) {
+                            if (dataId == temp.getId()) {
+                                sqlData = temp;
+                                break;
+                            }
+                        }
+                    }
+
+                    // 如果没找到，创建新的数据对象
+                    if (sqlData == null) {
+                        sqlData = new SqlData(mContext);
+                        mDataList.add(sqlData);
+                    }
+
+                    // 设置数据内容
+                    sqlData.setContent(data);
+                }
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return false;
+        }
+        return true;
+    }
+
+
+    /**
+     * @method  getContent
+     * @description 将便签对象序列化为JSON格式，用于网络传输或数据交换
+     * @param
+     * @return JSONObject 包含便签内容的JSON对象
+     */
+    public JSONObject getContent() {
+        try {
+            JSONObject js = new JSONObject();
+
+            if (mIsCreate) {
+                Log.e(TAG, "it seems that we haven't created this in database yet");
+                return null;
+            }
+
+            JSONObject note = new JSONObject();
+
+            // 普通便签：包含完整字段和数据
+            if (mType == Notes.TYPE_NOTE) {
+                note.put(NoteColumns.ID, mId);
+                note.put(NoteColumns.ALERTED_DATE, mAlertDate);
+                note.put(NoteColumns.BG_COLOR_ID, mBgColorId);
+                note.put(NoteColumns.CREATED_DATE, mCreatedDate);
+                note.put(NoteColumns.HAS_ATTACHMENT, mHasAttachment);
+                note.put(NoteColumns.MODIFIED_DATE, mModifiedDate);
+                note.put(NoteColumns.PARENT_ID, mParentId);
+                note.put(NoteColumns.SNIPPET, mSnippet);
+                note.put(NoteColumns.TYPE, mType);
+                note.put(NoteColumns.WIDGET_ID, mWidgetId);
+                note.put(NoteColumns.WIDGET_TYPE, mWidgetType);
+                note.put(NoteColumns.ORIGIN_PARENT_ID, mOriginParent);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+
+                // 添加数据内容
+                JSONArray dataArray = new JSONArray();
+                for (SqlData sqlData : mDataList) {
+                    JSONObject data = sqlData.getContent();
+                    if (data != null) {
+                        dataArray.put(data);
+                    }
+                }
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
+            }
+            // 文件夹和系统文件夹：仅包含ID、类型和片段
+            else if (mType == Notes.TYPE_FOLDER || mType == Notes.TYPE_SYSTEM) {
+                note.put(NoteColumns.ID, mId);
+                note.put(NoteColumns.TYPE, mType);
+                note.put(NoteColumns.SNIPPET, mSnippet);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+            }
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+
+    public void setParentId(long id) {
+        mParentId = id;
+        mDiffNoteValues.put(NoteColumns.PARENT_ID, id);
+    }
+
+    //设置Google Task ID
+    public void setGtaskId(String gid) {
+        mDiffNoteValues.put(NoteColumns.GTASK_ID, gid);
+    }
+
+    //设置同步ID
+    public void setSyncId(long syncId) {
+        mDiffNoteValues.put(NoteColumns.SYNC_ID, syncId);
+    }
+
+    //重置本地修改标记。在同步完成后调用，表示便签已经与远程同步
+    public void resetLocalModified() {
+        mDiffNoteValues.put(NoteColumns.LOCAL_MODIFIED, 0);
+    }
+
+
+    public long getId() {
+        return mId;
+    }
+
+
+    public long getParentId() {
+        return mParentId;
+    }
+
+
+    public String getSnippet() {
+        return mSnippet;
+    }
+
+    //判断是否为普通便签类型
+    public boolean isNoteType() {
+        return mType == Notes.TYPE_NOTE;
+    }
+
+
+    /**
+     * @method  commit
+     * @description 提交便签到数据库
+     * @param validateVersion 是否验证版本号
+     * @return
+     */
+    public void commit(boolean validateVersion) {
+        // 新便签：执行INSERT操作
+        if (mIsCreate) {
+            // 如果ID是无效值，从变更记录中移除ID字段，让数据库自动生成
+            if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
+                mDiffNoteValues.remove(NoteColumns.ID);
+            }
+
+            // 执行插入操作
+            Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues);
+            try {
+                // 从返回的URI中提取新便签的ID
+                // URI格式：content://authority/note/{note_id}
+                mId = Long.valueOf(uri.getPathSegments().get(1));
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString());
+                throw new ActionFailureException("create note failed");
+            }
+
+            if (mId == 0) {
+                throw new IllegalStateException("Create thread id failed");
+            }
+
+            // 如果是普通便签，提交关联的所有数据
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, false, -1);
+                }
+            }
+        }
+        // 现有便签：执行UPDATE操作
+        else {
+            // 检查便签ID有效性
+            if (mId <= 0 && mId != Notes.ID_ROOT_FOLDER && mId != Notes.ID_CALL_RECORD_FOLDER) {
+                Log.e(TAG, "No such note");
+                throw new IllegalStateException("Try to update note with invalid id");
+            }
+
+            // 如果有变更，执行更新操作
+            if (mDiffNoteValues.size() > 0) {
+                mVersion ++;  // 版本号自增
+                int result = 0;
+
+                if (!validateVersion) {
+                    // 不验证版本：直接更新
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                            + NoteColumns.ID + "=?)", new String[] {
+                            String.valueOf(mId)
+                    });
+                } else {
+                    // 验证版本：使用乐观锁机制
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                                    + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
+                            new String[] {
+                                    String.valueOf(mId), String.valueOf(mVersion)
+                            });
+                }
+
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
+                }
+            }
+
+            // 如果是普通便签，提交关联的所有数据
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, validateVersion, mVersion);
+                }
+            }
+        }
+
+        // 刷新本地信息：重新从数据库加载，确保数据一致性
+        loadFromCursor(mId);
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+
+        // 清除变更记录，更新对象状态
+        mDiffNoteValues.clear();
+        mIsCreate = false;
+    }
+}

src/gtask/data/Task.java

@@ -0,0 +1,417 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+  *
+  * @Package:        net.micode.notes.gtask.data
+  * @ClassName:      Task
+  * @Description:    表示任务节点，包含任务的具体属性和行为
+ */
+public class Task extends Node {
+    private static final String TAG = Task.class.getSimpleName();
+
+    private boolean mCompleted;//任务是否完成
+
+    private String mNotes;//任务
+
+    private JSONObject mMetaInfo; //任务的元数据信息
+
+    private Task mPriorSibling;//任务的前一个兄弟任务
+
+    private TaskList mParent; //任务所属的任务列表
+
+    public Task() {
+        super();
+        mCompleted = false;
+        mNotes = null;
+        mPriorSibling = null;
+        mParent = null;
+        mMetaInfo = null;
+    }
+
+    /**
+     * @method  getCreateAction
+     * @description 生成任务创建操作的 JSON 对象表示
+     * @param actionId
+     * @return JSONObject
+     */
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            //添加任务创建操作的类型标识
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+            // action_id
+            //添加操作的唯一标识符
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // index
+            //添加任务在其父任务列表中的索引位置
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mParent.getChildTaskIndex(this));
+
+            // entity_delta
+            //初始化entity,表示任务的具体属性,添加名称、创建者标识、类型和便签
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_TASK);
+            if (getNotes() != null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+            }
+
+            //添加任务的完成状态
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+            // parent_id
+            //添加任务所属的父任务列表的标识符
+            js.put(GTaskStringUtils.GTASK_JSON_PARENT_ID, mParent.getGid());
+
+            // dest_parent_type
+            //添加任务所属的父任务列表的类型标识
+            js.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+
+            // list_id
+            //添加任务所属的任务列表的标识符
+            js.put(GTaskStringUtils.GTASK_JSON_LIST_ID, mParent.getGid());
+
+            // prior_sibling_id
+            //添加任务的前一个兄弟任务的标识符（如果有的话）
+            if (mPriorSibling != null) {
+                js.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, mPriorSibling.getGid());
+            }
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate task-create jsonobject");
+        }
+
+        return js;
+    }
+
+    /**
+     * @method  getUpdateAction
+     * @description 生成任务更新操作的 JSON 对象表示
+     * @param actionId
+     * @return JSONObject
+     */
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // id
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            if (getNotes() != null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+            }
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate task-update jsonobject");
+        }
+
+        return js;
+    }
+
+    /**
+     * @method  setContentByRemoteJSON
+     * @description 从远程 JSON 对象设置任务的内容
+     * @param js 包含任务内容的 JSON 对象
+     * @return
+     */
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js != null) {
+            try {
+                // id
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+                // last_modified
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+                // name
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+                // notes
+                if (js.has(GTaskStringUtils.GTASK_JSON_NOTES)) {
+                    setNotes(js.getString(GTaskStringUtils.GTASK_JSON_NOTES));
+                }
+
+                // deleted
+                if (js.has(GTaskStringUtils.GTASK_JSON_DELETED)) {
+                    setDeleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_DELETED));
+                }
+
+                // completed
+                if (js.has(GTaskStringUtils.GTASK_JSON_COMPLETED)) {
+                    setCompleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_COMPLETED));
+                }
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("fail to get task content from jsonobject");
+            }
+        }
+    }
+
+    /**
+     * @method  setContentByLocalJSON
+     * @description 从本地 JSON 对象设置任务的内容
+     * @param js 包含任务内容的 JSON 对象
+     * @return
+     */
+    public void setContentByLocalJSON(JSONObject js) {
+        //如果传入的 JSON 对象为空或缺少必要的字段，则记录警告日志
+        if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)
+                || !js.has(GTaskStringUtils.META_HEAD_DATA)) {
+            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
+        }
+
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+            //如果类型不匹配，则记录错误日志并返回
+            if (note.getInt(NoteColumns.TYPE) != Notes.TYPE_NOTE) {
+                Log.e(TAG, "invalid type");
+                return;
+            }
+
+            for (int i = 0; i < dataArray.length(); i++) {
+                JSONObject data = dataArray.getJSONObject(i);
+                //找到文本便签的数据，并设置任务的名称
+                if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                    setName(data.getString(DataColumns.CONTENT));
+                    break;
+                }
+            }
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * @method  getLocalJSONFromContent
+     * @description 将任务的内容转换为本地 JSON 对象表示
+     * @return JSONObject 表示任务内容的本地 JSON 对象
+     */
+    public JSONObject getLocalJSONFromContent() {
+        String name = getName();
+        try {
+            //如果元数据信息为空，表示是从远程创建的新任务
+            if (mMetaInfo == null) {
+                // new task created from web
+                if (name == null) {
+                    Log.w(TAG, "the note seems to be an empty one");
+                    return null;
+                }
+
+                JSONObject js = new JSONObject();
+                JSONObject note = new JSONObject();
+                JSONArray dataArray = new JSONArray();
+                JSONObject data = new JSONObject();
+                //构建表示任务内容的本地 JSON 对象
+                data.put(DataColumns.CONTENT, name);
+                dataArray.put(data);
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+                return js;
+            } else {
+                // synced task
+                JSONObject note = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+                JSONArray dataArray = mMetaInfo.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                        data.put(DataColumns.CONTENT, getName());
+                        break;
+                    }
+                }
+
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                return mMetaInfo;
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    /**
+     * @method  setMetaInfo
+     * @description 设置任务的元数据信息
+     * @param metaData 包含任务元数据信息的 MetaData 对象
+     * @return
+     */
+    public void setMetaInfo(MetaData metaData) {
+        if (metaData != null && metaData.getNotes() != null) {
+            try {
+                mMetaInfo = new JSONObject(metaData.getNotes());//将 MetaData 对象的便签信息解析为 JSON 对象并存储
+            } catch (JSONException e) {
+                Log.w(TAG, e.toString());
+                mMetaInfo = null;
+            }
+        }
+    }
+
+    /**
+     * @method  getSyncAction
+     * @description 确定任务与本地数据的同步操作类型
+     * @param c：表示本地任务数据的数据库游标
+     * @return int：表示同步操作类型的整数值
+     */
+    public int getSyncAction(Cursor c) {
+        try {
+            JSONObject noteInfo = null;
+            if (mMetaInfo != null && mMetaInfo.has(GTaskStringUtils.META_HEAD_NOTE)) {
+                noteInfo = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            }
+
+            if (noteInfo == null) {
+                Log.w(TAG, "it seems that note meta has been deleted");
+                return SYNC_ACTION_UPDATE_REMOTE;
+            }
+
+            if (!noteInfo.has(NoteColumns.ID)) {
+                Log.w(TAG, "remote note id seems to be deleted");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+            // validate the note id now
+            //如果本地数据的 ID 与远程数据的 ID 不匹配
+            if (c.getLong(SqlNote.ID_COLUMN) != noteInfo.getLong(NoteColumns.ID)) {
+                Log.w(TAG, "note id doesn't match");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+            //如果本地数据的修改标志为 0，即没有本地更新
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // there is no local update
+                //如果本地数据的同步 ID 与任务的最后修改时间戳匹配
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // no update both side
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // apply remote to local 远程更新
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // validate gtask id
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "gtask id doesn't match");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // local modification only 仅本地更新
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    //本地-远程更新 更新冲突
+                    return SYNC_ACTION_UPDATE_CONFLICT;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+        return SYNC_ACTION_ERROR;
+    }
+
+    //任务有元数据信息，或名称非空，或便签非空，则认为值得保存
+    public boolean isWorthSaving() {
+        return mMetaInfo != null || (getName() != null && getName().trim().length() > 0)
+                || (getNotes() != null && getNotes().trim().length() > 0);
+    }
+
+    public void setCompleted(boolean completed) {
+        this.mCompleted = completed;
+    }
+
+    public void setNotes(String notes) {
+        this.mNotes = notes;
+    }
+
+    public void setPriorSibling(Task priorSibling) {
+        this.mPriorSibling = priorSibling;
+    }
+
+    public void setParent(TaskList parent) {
+        this.mParent = parent;
+    }
+
+    public boolean getCompleted() {
+        return this.mCompleted;
+    }
+
+    public String getNotes() {
+        return this.mNotes;
+    }
+
+    public Task getPriorSibling() {
+        return this.mPriorSibling;
+    }
+
+    public TaskList getParent() {
+        return this.mParent;
+    }
+
+}

src/gtask/data/TaskList.java

@@ -0,0 +1,364 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+
+/**     
+  * 
+  * @Package:        net.micode.notes.gtask.data
+  * @ClassName:      TaskList
+  * @Description:     表示一个任务列表（或任务组），继承自Node类。
+  *                  1. 管理任务列表中的子任务（Task对象）
+  *                  2. 处理任务列表与Google Task API的JSON数据转换
+  *                  3. 处理任务列表与本地数据库的同步逻辑
+  *                  4. 管理任务列表在远程服务中的创建、更新和删除操作 
+ */
+public class TaskList extends Node {
+    private static final String TAG = TaskList.class.getSimpleName();
+
+    private int mIndex;
+
+    private ArrayList<Task> mChildren;
+
+    public TaskList() {
+        super();
+        mChildren = new ArrayList<Task>();
+        mIndex = 1;
+    }
+
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // index
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mIndex);
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate tasklist-create jsonobject");
+        }
+
+        return js;
+    }
+
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // id
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate tasklist-update jsonobject");
+        }
+
+        return js;
+    }
+
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js != null) {
+            try {
+                // id
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+                // last_modified
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+                // name
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("fail to get tasklist content from jsonobject");
+            }
+        }
+    }
+
+    public void setContentByLocalJSON(JSONObject js) {
+        if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)) {
+            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
+        }
+
+        try {
+            JSONObject folder = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+
+            //如果是文件夹类型，则设置名称为“文件夹：名称”
+            if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                String name = folder.getString(NoteColumns.SNIPPET);
+                setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + name);
+            }
+
+            //否则如果是系统文件夹类型，则根据ID设置名称
+            else if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                if (folder.getLong(NoteColumns.ID) == Notes.ID_ROOT_FOLDER)//如果是根文件夹
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT);//设置名称为“文件夹：默认文件夹”
+                else if (folder.getLong(NoteColumns.ID) == Notes.ID_CALL_RECORD_FOLDER)//如果是通话记录文件夹
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX
+                            + GTaskStringUtils.FOLDER_CALL_NOTE);//设置名称为“文件夹：通话记录”
+                else
+                    Log.e(TAG, "invalid system folder");
+            } else {
+                Log.e(TAG, "error type");
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+    public JSONObject getLocalJSONFromContent() {
+        try {
+            JSONObject js = new JSONObject();
+            JSONObject folder = new JSONObject();
+
+            String folderName = getName();
+            if (getName().startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX))
+                folderName = folderName.substring(GTaskStringUtils.MIUI_FOLDER_PREFFIX.length(),
+                        folderName.length());
+            folder.put(NoteColumns.SNIPPET, folderName);
+            if (folderName.equals(GTaskStringUtils.FOLDER_DEFAULT)
+                    || folderName.equals(GTaskStringUtils.FOLDER_CALL_NOTE))
+                folder.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+            else
+                folder.put(NoteColumns.TYPE, Notes.TYPE_FOLDER);
+
+            js.put(GTaskStringUtils.META_HEAD_NOTE, folder);
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public int getSyncAction(Cursor c) {
+        try {
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // there is no local update
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // no update both side
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // apply remote to local
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // validate gtask id
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "gtask id doesn't match");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // local modification only
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    // for folder conflicts, just apply local modification
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+        return SYNC_ACTION_ERROR;
+    }
+
+    public int getChildTaskCount() {
+        return mChildren.size();
+    }
+
+    public boolean addChildTask(Task task) {
+        boolean ret = false;
+        //如果任务不为空且不在子任务列表中，添加子任务
+        if (task != null && !mChildren.contains(task)) {
+            ret = mChildren.add(task);
+            if (ret) {
+                // need to set prior sibling and parent 设置兄弟节点和父节点
+                task.setPriorSibling(mChildren.isEmpty() ? null : mChildren
+                        .get(mChildren.size() - 1));//如果前一个任务为空，则设置前一个任务为null，否则设置为子任务列表中的最后一个任务
+                task.setParent(this);
+            }
+        }
+        return ret;
+    }
+
+    // 在指定位置添加子任务
+    public boolean addChildTask(Task task, int index) {
+        if (index < 0 || index > mChildren.size()) {
+            Log.e(TAG, "add child task: invalid index");
+            return false;
+        }
+
+        int pos = mChildren.indexOf(task);//获取任务在子任务列表中的位置
+        if (task != null && pos == -1) {
+            mChildren.add(index, task);
+
+            // update the task list
+            //更新任务列表
+            Task preTask = null;
+            Task afterTask = null;
+            if (index != 0)
+                preTask = mChildren.get(index - 1);
+            if (index != mChildren.size() - 1)
+                afterTask = mChildren.get(index + 1);
+            task.setPriorSibling(preTask);
+            if (afterTask != null)
+                afterTask.setPriorSibling(task);
+        }
+
+        return true;
+    }
+
+    public boolean removeChildTask(Task task) {
+        boolean ret = false;
+        int index = mChildren.indexOf(task);
+        if (index != -1) {
+            ret = mChildren.remove(task);
+
+            if (ret) {
+                // reset prior sibling and parent
+                task.setPriorSibling(null);
+                task.setParent(null);
+
+                // update the task list
+                if (index != mChildren.size()) {
+                    //如果被移除任务不是最后一个任务，则将其后一个任务的前一个任务设置为被移除任务的前一个任务
+                    mChildren.get(index).setPriorSibling(
+                            index == 0 ? null : mChildren.get(index - 1));
+                }
+            }
+        }
+        return ret;
+    }
+
+    // 移动子任务到指定位置
+    public boolean moveChildTask(Task task, int index) {
+
+        if (index < 0 || index >= mChildren.size()) {
+            Log.e(TAG, "move child task: invalid index");
+            return false;
+        }
+
+        int pos = mChildren.indexOf(task);
+        if (pos == -1) {
+            Log.e(TAG, "move child task: the task should in the list");
+            return false;
+        }
+
+        if (pos == index)
+            return true;
+        return (removeChildTask(task) && addChildTask(task, index));//先移除任务，再添加到指定位置
+    }
+
+
+    public Task findChildTaskByGid(String gid) {
+        for (int i = 0; i < mChildren.size(); i++) {
+            Task t = mChildren.get(i);
+            if (t.getGid().equals(gid)) {
+                return t;
+            }
+        }
+        return null;
+    }
+
+    // 根据任务获取子任务索引
+    public int getChildTaskIndex(Task task) {
+        return mChildren.indexOf(task);
+    }
+
+    // 根据索引获取子任务
+    public Task getChildTaskByIndex(int index) {
+        if (index < 0 || index >= mChildren.size()) {
+            Log.e(TAG, "getTaskByIndex: invalid index");
+            return null;
+        }
+        return mChildren.get(index);
+    }
+
+    // 根据 GID 获取子任务
+    public Task getChilTaskByGid(String gid) {
+        for (Task task : mChildren) {
+            if (task.getGid().equals(gid))
+                return task;
+        }
+        return null;
+    }
+
+    public ArrayList<Task> getChildTaskList() {
+        return this.mChildren;
+    }
+
+    public void setIndex(int index) {
+        this.mIndex = index;
+    }
+
+    public int getIndex() {
+        return this.mIndex;
+    }
+}

src/gtask/exception/ActionFailureException.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.exception;
+
+// 自定义异常类：表示操作失败的异常
+public class ActionFailureException extends RuntimeException {
+    private static final long serialVersionUID = 4425249765923293627L;//序列化版本号
+
+    // 构造方法
+    public ActionFailureException() {
+        super();
+    }
+
+    // 构造方法，带有错误信息
+    public ActionFailureException(String paramString) {
+        super(paramString);
+    }
+
+    // 构造方法，带有错误信息和原因
+    public ActionFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable);
+    }
+}

src/gtask/exception/NetworkFailureException.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.exception;
+
+// 自定义异常类：表示网络故障的异常
+public class NetworkFailureException extends Exception {
+    private static final long serialVersionUID = 2107610287180234136L;//序列化版本号
+
+    // 构造方法
+    public NetworkFailureException() {
+        super();
+    }
+
+    // 构造方法，带有错误信息
+    public NetworkFailureException(String paramString) {
+        super(paramString);
+    }
+
+    // 构造方法，带有错误信息和原因
+    public NetworkFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable);
+    }
+}

src/gtask/remote/GTaskASyncTask.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.os.AsyncTask;
+
+import net.micode.notes.R;
+import net.micode.notes.ui.NotesListActivity;
+import net.micode.notes.ui.NotesPreferenceActivity;
+
+
+/**
+  *
+  * @Package:        net.micode.notes.gtask.remote
+  * @ClassName:      GTaskASyncTask
+  * @Description:    1. 在后台线程执行Google Task同步操作
+ *                   2. 显示同步进度通知
+ *                   3. 处理同步完成后的结果展示
+ *                   4. 支持同步取消操作
+ */
+public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
+
+    private static int GTASK_SYNC_NOTIFICATION_ID = 5234235;  // 同步通知ID
+
+    //同步完成监听器接口 用于通知同步服务的完成事件
+    public interface OnCompleteListener {
+        void onComplete();
+    }
+
+    private Context mContext; // Android上下文
+    private NotificationManager mNotifiManager;  // 通知管理器
+    private GTaskManager mTaskManager;        // 同步管理器
+    private OnCompleteListener mOnCompleteListener;  // 完成监听器
+
+
+    public GTaskASyncTask(Context context, OnCompleteListener listener) {
+        mContext = context;
+        mOnCompleteListener = listener;
+        mNotifiManager = (NotificationManager) mContext
+                .getSystemService(Context.NOTIFICATION_SERVICE);
+        mTaskManager = GTaskManager.getInstance();
+    }
+
+
+    public void cancelSync() {
+        mTaskManager.cancelSync();
+    }
+
+    //发布同步进度
+    public void publishProgess(String message) {
+        publishProgress(new String[] {
+                message
+        });
+    }
+
+    /**
+     * @method  showNotification
+     * @description 显示同步通知
+     * @param tickerId 通知标题字符串资源ID
+     * @param content 通知内容
+     */
+    private void showNotification(int tickerId, String content) {
+        PendingIntent pendingIntent;
+        if (tickerId != R.string.ticker_success) {
+            // 同步中或失败：跳转到设置页面
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesPreferenceActivity.class), PendingIntent.FLAG_IMMUTABLE);
+        } else {
+            // 同步成功：跳转到便签列表页面
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesListActivity.class), PendingIntent.FLAG_IMMUTABLE);
+        }
+
+        // 构建通知
+        Notification.Builder builder = new Notification.Builder(mContext)
+                .setAutoCancel(true)
+                .setContentTitle(mContext.getString(R.string.app_name))
+                .setContentText(content)
+                .setContentIntent(pendingIntent)
+                .setWhen(System.currentTimeMillis())
+                .setOngoing(true);
+        Notification notification=builder.getNotification();
+        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);
+    }
+
+   
+    /**
+     * @method  doInBackground
+     * @description 在后台执行同步
+     * @param unused 未使用的参数（Void类型）
+     * @return 同步结果状态码
+     */
+    @Override
+    protected Integer doInBackground(Void... unused) {
+        // 发布登录进度
+        publishProgess(mContext.getString(R.string.sync_progress_login, NotesPreferenceActivity
+                .getSyncAccountName(mContext)));
+
+        // 执行同步
+        return mTaskManager.sync(mContext, this);
+    }
+
+
+    //更新同步进度
+    @Override
+    protected void onProgressUpdate(String... progress) {
+        showNotification(R.string.ticker_syncing, progress[0]);
+        if (mContext instanceof GTaskSyncService) {
+            ((GTaskSyncService) mContext).sendBroadcast(progress[0]);
+        }
+    }
+
+
+    //同步完成后处理。根据同步结果显示相应的通知，并调用完成监听器
+    @Override
+    protected void onPostExecute(Integer result) {
+        // 根据同步结果显示相应的通知
+        if (result == GTaskManager.STATE_SUCCESS) {
+            showNotification(R.string.ticker_success, mContext.getString(
+                    R.string.success_sync_account, mTaskManager.getSyncAccount()));
+            NotesPreferenceActivity.setLastSyncTime(mContext, System.currentTimeMillis());
+        } else if (result == GTaskManager.STATE_NETWORK_ERROR) {
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_network));
+        } else if (result == GTaskManager.STATE_INTERNAL_ERROR) {
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_internal));
+        } else if (result == GTaskManager.STATE_SYNC_CANCELLED) {
+            showNotification(R.string.ticker_cancel, mContext
+                    .getString(R.string.error_sync_cancelled));
+        }
+
+        // 调用完成监听器（在新线程中执行，避免阻塞UI）
+        if (mOnCompleteListener != null) {
+            new Thread(new Runnable() {
+                public void run() {
+                    mOnCompleteListener.onComplete();
+                }
+            }).start();
+        }
+    }
+}

src/gtask/remote/GTaskClient.java

@@ -0,0 +1,721 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.accounts.AccountManagerFuture;
+import android.app.Activity;
+import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.gtask.data.Node;
+import net.micode.notes.gtask.data.Task;
+import net.micode.notes.gtask.data.TaskList;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.gtask.exception.NetworkFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+import net.micode.notes.ui.NotesPreferenceActivity;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.ClientProtocolException;
+import org.apache.http.client.entity.UrlEncodedFormEntity;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.cookie.Cookie;
+import org.apache.http.impl.client.BasicCookieStore;
+import org.apache.http.impl.client.DefaultHttpClient;
+import org.apache.http.message.BasicNameValuePair;
+import org.apache.http.params.BasicHttpParams;
+import org.apache.http.params.HttpConnectionParams;
+import org.apache.http.params.HttpParams;
+import org.apache.http.params.HttpProtocolParams;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.Inflater;
+import java.util.zip.InflaterInputStream;
+
+
+/**     
+  * 
+  * @Package:        net.micode.notes.gtask.remote
+  * @ClassName:      GTaskClient
+  * @Description:    1. 封装与Google Task服务端的所有HTTP通信
+ *                   2. 处理用户认证、登录和会话管理
+ *                   3. 提供任务和任务列表的增删改查API
+ *                   4. 管理请求的动作ID和批量更新
+ */
+public class GTaskClient {
+    private static final String TAG = GTaskClient.class.getSimpleName();
+
+    private static final String GTASK_URL = "https://mail.google.com/tasks/";  // Google Task基础URL
+
+    private static final String GTASK_GET_URL = "https://mail.google.com/tasks/ig";  // GET请求URL
+
+    private static final String GTASK_POST_URL = "https://mail.google.com/tasks/r/ig";  // POST请求URL
+
+    private static GTaskClient mInstance = null;
+
+    private DefaultHttpClient mHttpClient;        // HTTP客户端，用于执行网络请求
+    private String mGetUrl;                       // 当前使用的GET请求URL
+    private String mPostUrl;                      // 当前使用的POST请求URL
+    private long mClientVersion;                  // 客户端版本号
+    private boolean mLoggedin;                    // 登录状态标记
+    private long mLastLoginTime;                  // 上次登录时间，用于会话超时控制
+    private int mActionId;                        // 动作ID计数器，确保每个请求有唯一ID
+    private Account mAccount;                     // 当前同步的Google账户
+    private JSONArray mUpdateArray;               // 批量更新数组，用于缓存更新操作
+
+
+    // 构造函数：实现单例模式
+
+    private GTaskClient() {
+        mHttpClient = null;
+        mGetUrl = GTASK_GET_URL;
+        mPostUrl = GTASK_POST_URL;
+        mClientVersion = -1;
+        mLoggedin = false;
+        mLastLoginTime = 0;
+        mActionId = 1;
+        mAccount = null;
+        mUpdateArray = null;
+    }
+
+    //获取单例实例
+    public static synchronized GTaskClient getInstance() {
+        if (mInstance == null) {
+            mInstance = new GTaskClient();
+        }
+        return mInstance;
+    }
+
+    /**
+     * 登录Google Task服务
+     * @param activity  用于获取账户授权令牌
+     * @return
+     */
+    public boolean login(Activity activity) {
+        // 检查会话超时：假设Cookie在5分钟后过期
+        final long interval = 1000 * 60 * 5;  // 5分钟
+        if (mLastLoginTime + interval < System.currentTimeMillis()) {
+            mLoggedin = false;
+        }
+
+        // 检查账户切换：如果当前账户与设置中的账户不同，需要重新登录
+        if (mLoggedin
+                && !TextUtils.equals(getSyncAccount().name, NotesPreferenceActivity
+                .getSyncAccountName(activity))) {
+            mLoggedin = false;
+        }
+
+        // 如果已经登录，直接返回成功
+        if (mLoggedin) {
+            Log.d(TAG, "already logged in");
+            return true;
+        }
+
+        // 记录本次登录时间
+        mLastLoginTime = System.currentTimeMillis();
+
+        // 获取Google账户授权令牌
+        String authToken = loginGoogleAccount(activity, false);
+        if (authToken == null) {
+            Log.e(TAG, "login google account failed");
+            return false;
+        }
+
+        // 尝试使用自定义域名登录（针对非Gmail用户）
+        if (!(mAccount.name.toLowerCase().endsWith("gmail.com") || mAccount.name.toLowerCase()
+                .endsWith("googlemail.com"))) {
+            StringBuilder url = new StringBuilder(GTASK_URL).append("a/");
+            int index = mAccount.name.indexOf('@') + 1;
+            String suffix = mAccount.name.substring(index);
+            url.append(suffix + "/");
+            mGetUrl = url.toString() + "ig";
+            mPostUrl = url.toString() + "r/ig";
+
+            if (tryToLoginGtask(activity, authToken)) {
+                mLoggedin = true;
+            }
+        }
+
+        // 如果自定义域名登录失败，尝试使用官方Google域名登录
+        if (!mLoggedin) {
+            mGetUrl = GTASK_GET_URL;
+            mPostUrl = GTASK_POST_URL;
+            if (!tryToLoginGtask(activity, authToken)) {
+                return false;
+            }
+        }
+
+        mLoggedin = true;
+        return true;
+    }
+
+    
+    /**
+     * @method  loginGoogleAccount
+     * @description 登录Google账户并获取授权令牌
+     *
+     *  执行流程：
+     *  1. 获取设备上的所有Google账户
+     *  2. 根据设置中的账户名称匹配账户
+     *  3. 使用AccountManager获取授权令牌
+     *  4. 可选择使令牌失效并重新获取（用于令牌过期情况）
+     *
+     * @param activity
+     * @param invalidateToken 是否使当前令牌失效并重新获取
+     * @return String 授权令牌字符串，获取失败返回null
+     */
+    private String loginGoogleAccount(Activity activity, boolean invalidateToken) {
+        String authToken;
+        AccountManager accountManager = AccountManager.get(activity);// 获取账户管理器
+        Account[] accounts = accountManager.getAccountsByType("com.google");// 获取所有Google账户
+
+        if (accounts.length == 0) {
+            Log.e(TAG, "there is no available google account");
+            return null;
+        }
+
+        // 根据设置中的账户名称查找对应账户
+        String accountName = NotesPreferenceActivity.getSyncAccountName(activity);
+        Account account = null;
+        for (Account a : accounts) {
+            if (a.name.equals(accountName)) {
+                account = a;
+                break;
+            }
+        }
+        if (account != null) {
+            mAccount = account;
+        } else {
+            Log.e(TAG, "unable to get an account with the same name in the settings");
+            return null;
+        }
+
+        // 获取授权令牌
+        AccountManagerFuture<Bundle> accountManagerFuture = accountManager.getAuthToken(account,
+                "goanna_mobile", null, activity, null, null);
+        try {
+            Bundle authTokenBundle = accountManagerFuture.getResult();
+            authToken = authTokenBundle.getString(AccountManager.KEY_AUTHTOKEN);
+
+            // 如果令牌失效，重新获取
+            if (invalidateToken) {
+                accountManager.invalidateAuthToken("com.google", authToken);
+                loginGoogleAccount(activity, false);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "get auth token failed");
+            authToken = null;
+        }
+
+        return authToken;
+    }
+
+
+    /**
+     * @method  tryToLoginGtask
+     * @description 描尝试登录Google Task服务
+     * 执行流程：
+     * 1. 使用授权令牌登录Google Task
+     * 2. 如果失败，可能是令牌过期，使令牌失效后重新获取并重试
+     *
+     * @param activity
+     * @param authToken 授权令牌
+     * @return
+     */ 
+    private boolean tryToLoginGtask(Activity activity, String authToken) {
+        if (!loginGtask(authToken)) {
+            // 令牌可能过期，使令牌失效并重新获取
+            authToken = loginGoogleAccount(activity, true);
+            if (authToken == null) {
+                Log.e(TAG, "login google account failed");
+                return false;
+            }
+
+            if (!loginGtask(authToken)) {
+                Log.e(TAG, "login gtask failed");
+                return false;
+            }
+        }
+        return true;
+    }
+
+
+    /**
+     * @method  loginGtask
+     * @description 使用授权令牌登录Google Task服务
+     * 执行流程：
+     * 1. 配置HTTP客户端参数（连接超时、Socket超时）
+     * 2. 设置Cookie存储
+     * 3. 构建登录URL并发送GET请求
+     * 4. 验证返回的Cookie中是否包含认证Cookie（GTL）
+     * 5. 解析响应内容，获取客户端版本号
+     *
+     * @param authToken 授权令牌
+     * @return true登录成功，false登录失败
+     */
+    private boolean loginGtask(String authToken) {
+        // 配置HTTP客户端参数
+        int timeoutConnection = 10000;    // 连接超时10秒
+        int timeoutSocket = 15000;        // Socket超时15秒
+        HttpParams httpParameters = new BasicHttpParams();
+        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
+        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
+        mHttpClient = new DefaultHttpClient(httpParameters);
+
+        // 设置Cookie存储
+        BasicCookieStore localBasicCookieStore = new BasicCookieStore();
+        mHttpClient.setCookieStore(localBasicCookieStore);
+        HttpProtocolParams.setUseExpectContinue(mHttpClient.getParams(), false);
+
+        // 登录Google Task
+        try {
+            String loginUrl = mGetUrl + "?auth=" + authToken;
+            HttpGet httpGet = new HttpGet(loginUrl);
+            HttpResponse response = null;
+            response = mHttpClient.execute(httpGet);
+
+            // 检查认证Cookie是否获取成功
+            List<Cookie> cookies = mHttpClient.getCookieStore().getCookies();
+            boolean hasAuthCookie = false;
+            for (Cookie cookie : cookies) {
+                if (cookie.getName().contains("GTL")) {
+                    hasAuthCookie = true;
+                }
+            }
+            if (!hasAuthCookie) {
+                Log.w(TAG, "it seems that there is no auth cookie");
+            }
+
+            // 解析响应内容，获取客户端版本号
+            String resString = getResponseContent(response.getEntity());
+            String jsBegin = "_setup(";
+            String jsEnd = ")}</script>";
+            int begin = resString.indexOf(jsBegin);
+            int end = resString.lastIndexOf(jsEnd);
+            String jsString = null;
+            if (begin != -1 && end != -1 && begin < end) {
+                jsString = resString.substring(begin + jsBegin.length(), end);
+            }
+            JSONObject js = new JSONObject(jsString);
+            mClientVersion = js.getLong("v");
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return false;
+        } catch (Exception e) {
+            // 捕获所有异常，确保稳定性
+            Log.e(TAG, "httpget gtask_url failed");
+            return false;
+        }
+
+        return true;
+    }
+
+    //获取下一个动作ID
+    private int getActionId() {
+        return mActionId++;
+    }
+
+    //创建HTTP POST请求对象
+    private HttpPost createHttpPost() {
+        HttpPost httpPost = new HttpPost(mPostUrl);
+        httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
+        httpPost.setHeader("AT", "1");  // AT=1表示使用Cookie认证
+        return httpPost;
+    }
+
+    /**
+     * @method  getResponseContent
+     * @description 从HttpEntity获取响应内容
+     * @param entity HTTP响应实体
+     * @return 响应内容字符串
+     * @throws IOException 读取响应内容时发生IO异常
+     */
+    private String getResponseContent(HttpEntity entity) throws IOException {
+        String contentEncoding = null;
+        if (entity.getContentEncoding() != null) {
+            contentEncoding = entity.getContentEncoding().getValue();
+            Log.d(TAG, "encoding: " + contentEncoding);
+        }
+
+        InputStream input = entity.getContent();
+        // 根据压缩编码选择对应的解压流
+        if (contentEncoding != null && contentEncoding.equalsIgnoreCase("gzip")) {
+            input = new GZIPInputStream(entity.getContent());
+        } else if (contentEncoding != null && contentEncoding.equalsIgnoreCase("deflate")) {
+            Inflater inflater = new Inflater(true);
+            input = new InflaterInputStream(entity.getContent(), inflater);
+        }
+
+        try {
+            InputStreamReader isr = new InputStreamReader(input);
+            BufferedReader br = new BufferedReader(isr);
+            StringBuilder sb = new StringBuilder();
+
+            while (true) {
+                String buff = br.readLine();
+                if (buff == null) {
+                    return sb.toString();
+                }
+                sb = sb.append(buff);
+            }
+        } finally {
+            input.close();  // 确保流被关闭
+        }
+    }
+
+    /**
+     *
+    /**
+     * @method  postRequest
+     * @description 发送POST请求到Google Task服务
+     * 执行流程：
+     * 1. 验证登录状态
+     * 2. 创建HttpPost请求
+     * 3. 将JSON对象编码为表单参数
+     * 4. 执行请求并获取响应
+     * 5. 解析响应内容为JSON对象
+     *
+     * @param js 要发送的JSON对象
+     * @return 服务器响应的JSON对象
+     * @throws NetworkFailureException 网络请求失败
+     * @throws ActionFailureException JSON解析或处理失败
+     */
+    private JSONObject postRequest(JSONObject js) throws NetworkFailureException {
+        if (!mLoggedin) {
+            Log.e(TAG, "please login first");
+            throw new ActionFailureException("not logged in");
+        }
+
+        HttpPost httpPost = createHttpPost();
+        try {
+            // 将JSON对象编码为表单参数
+            LinkedList<BasicNameValuePair> list = new LinkedList<BasicNameValuePair>();
+            list.add(new BasicNameValuePair("r", js.toString()));
+            UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, "UTF-8");
+            httpPost.setEntity(entity);
+
+            // 执行POST请求
+            HttpResponse response = mHttpClient.execute(httpPost);
+            String jsString = getResponseContent(response.getEntity());
+            return new JSONObject(jsString);
+
+        } catch (ClientProtocolException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("postRequest failed");
+        } catch (IOException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("postRequest failed");
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("unable to convert response content to jsonobject");
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("error occurs when posting request");
+        }
+    }
+
+    /**
+     * @method  createTask
+     * @description 创建任务
+     * 执行流程：
+     * 1. 提交已有的批量更新
+     * 2. 构建创建任务的JSON请求
+     * 3. 发送请求到服务器
+     * 4. 从响应中提取新任务的ID并设置到任务对象
+     *
+     * @param task 要创建的任务对象
+     * @throws NetworkFailureException 网络请求失败
+     */
+    public void createTask(Task task) throws NetworkFailureException {
+        commitUpdate();  // 先提交已有的批量更新
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+
+            // 构建动作列表：包含创建任务的动作
+            actionList.put(task.getCreateAction(getActionId()));
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+            // 添加客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+            // 发送请求并处理响应
+            JSONObject jsResponse = postRequest(jsPost);
+            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(
+                    GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
+            task.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID));
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("create task: handing jsonobject failed");
+        }
+    }
+
+
+    /**
+     * @method  createTaskList
+     * @description 创建任务列表
+     * 执行流程：
+     * 1. 提交已有的批量更新
+     * 2. 构建创建任务列表的JSON请求
+     * 3. 发送请求到服务器
+     * 4. 从响应中提取新任务列表的ID并设置到任务列表对象
+     *
+     * @param tasklist 要创建的任务列表对象
+     * @throws NetworkFailureException 网络请求失败
+     */
+    public void createTaskList(TaskList tasklist) throws NetworkFailureException {
+        commitUpdate();  // 先提交已有的批量更新
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+
+            // 构建动作列表：包含创建任务列表的动作
+            actionList.put(tasklist.getCreateAction(getActionId()));
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+            // 添加客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+            // 发送请求并处理响应
+            JSONObject jsResponse = postRequest(jsPost);
+            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(
+                    GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
+            tasklist.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID));
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("create tasklist: handing jsonobject failed");
+        }
+    }
+
+
+    //提交批量更新
+    public void commitUpdate() throws NetworkFailureException {
+        if (mUpdateArray != null) {
+            try {
+                JSONObject jsPost = new JSONObject();
+
+                // 添加缓存的更新动作列表
+                jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, mUpdateArray);
+
+                // 添加客户端版本号
+                jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+                // 发送请求
+                postRequest(jsPost);
+                mUpdateArray = null;  // 清空更新数组
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("commit update: handing jsonobject failed");
+            }
+        }
+    }
+
+
+    //将节点的更新操作添加到批量更新数组中
+    public void addUpdateNode(Node node) throws NetworkFailureException {
+        if (node != null) {
+            // 优化：更新项太多可能导致错误，设置最大为10项
+            if (mUpdateArray != null && mUpdateArray.length() > 10) {
+                commitUpdate();
+            }
+
+            // 初始化更新数组并添加更新动作
+            if (mUpdateArray == null)
+                mUpdateArray = new JSONArray();
+            mUpdateArray.put(node.getUpdateAction(getActionId()));
+        }
+    }
+
+    /**
+     * @method  moveTask
+     * @description 将任务从一个任务列表移动到另一个任务列表
+     * @param task 要移动的任务
+     * @param preParent 移动前的父任务列表
+     * @param curParent 移动后的父任务列表
+     * @throws NetworkFailureException 网络请求失败
+     */
+    public void moveTask(Task task, TaskList preParent, TaskList curParent)
+            throws NetworkFailureException {
+        commitUpdate();  // 先提交已有的批量更新
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+            JSONObject action = new JSONObject();
+
+            // 构建移动动作
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_MOVE);
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
+            action.put(GTaskStringUtils.GTASK_JSON_ID, task.getGid());
+
+            // 在同一任务列表内移动且不是第一个时，设置前一个兄弟节点ID
+            if (preParent == curParent && task.getPriorSibling() != null) {
+                action.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, task.getPriorSibling());
+            }
+
+            action.put(GTaskStringUtils.GTASK_JSON_SOURCE_LIST, preParent.getGid());
+            action.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT, curParent.getGid());
+
+            // 在不同任务列表之间移动时，设置目标列表ID
+            if (preParent != curParent) {
+                action.put(GTaskStringUtils.GTASK_JSON_DEST_LIST, curParent.getGid());
+            }
+
+            actionList.put(action);
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+            // 添加客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+            postRequest(jsPost);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("move task: handing jsonobject failed");
+        }
+    }
+
+
+    //Google Task中删除节点
+    public void deleteNode(Node node) throws NetworkFailureException {
+        commitUpdate();  // 先提交已有的批量更新
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+
+            // 构建删除动作
+            node.setDeleted(true);
+            actionList.put(node.getUpdateAction(getActionId()));
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+            // 添加客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+            postRequest(jsPost);
+            mUpdateArray = null;  // 清空更新数组
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("delete node: handing jsonobject failed");
+        }
+    }
+
+
+    //获取当前账户下的所有任务列表
+    public JSONArray getTaskLists() throws NetworkFailureException {
+        if (!mLoggedin) {
+            Log.e(TAG, "please login first");
+            throw new ActionFailureException("not logged in");
+        }
+
+        try {
+            HttpGet httpGet = new HttpGet(mGetUrl);
+            HttpResponse response = null;
+            response = mHttpClient.execute(httpGet);
+
+            // 解析响应内容，提取任务列表信息
+            String resString = getResponseContent(response.getEntity());
+            String jsBegin = "_setup(";
+            String jsEnd = ")}</script>";
+            int begin = resString.indexOf(jsBegin);
+            int end = resString.lastIndexOf(jsEnd);
+            String jsString = null;
+            if (begin != -1 && end != -1 && begin < end) {
+                jsString = resString.substring(begin + jsBegin.length(), end);
+            }
+            JSONObject js = new JSONObject(jsString);
+            return js.getJSONObject("t").getJSONArray(GTaskStringUtils.GTASK_JSON_LISTS);
+        } catch (ClientProtocolException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("gettasklists: httpget failed");
+        } catch (IOException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new NetworkFailureException("gettasklists: httpget failed");
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("get task lists: handing jasonobject failed");
+        }
+    }
+
+    //获取特定任务列表下的所有任务
+    public JSONArray getTaskList(String listGid) throws NetworkFailureException {
+        commitUpdate();  // 先提交已有的批量更新
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+            JSONObject action = new JSONObject();
+
+            // 构建获取所有任务的动作
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_GETALL);
+            action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
+            action.put(GTaskStringUtils.GTASK_JSON_LIST_ID, listGid);
+            action.put(GTaskStringUtils.GTASK_JSON_GET_DELETED, false);  // 不获取已删除的任务
+            actionList.put(action);
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+
+            // 添加客户端版本号
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);
+
+            // 发送请求并获取响应
+            JSONObject jsResponse = postRequest(jsPost);
+            return jsResponse.getJSONArray(GTaskStringUtils.GTASK_JSON_TASKS);
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("get task list: handing jsonobject failed");
+        }
+    }
+
+    //获取当前同步账户
+    public Account getSyncAccount() {
+        return mAccount;
+    }
+
+    //重置更新数组
+    public void resetUpdateArray() {
+        mUpdateArray = null;
+    }
+}

src/gtask/remote/GTaskManager.java

@@ -0,0 +1,919 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.app.Activity;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.data.MetaData;
+import net.micode.notes.gtask.data.Node;
+import net.micode.notes.gtask.data.SqlNote;
+import net.micode.notes.gtask.data.Task;
+import net.micode.notes.gtask.data.TaskList;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.gtask.exception.NetworkFailureException;
+import net.micode.notes.tool.DataUtils;
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+
+
+/**
+  *
+  * @Package:        net.micode.notes.gtask.remote
+  * @ClassName:      GTaskManager
+  * @Description:
+ *  1. 协调本地SQLite数据库与Google Task之间的双向同步
+ *  2. 管理同步状态和冲突解决策略
+ *  3. 维护本地ID与Google Task ID之间的映射关系
+ *  4. 处理文件夹、便签和元数据的完整同步逻辑
+ */
+public class GTaskManager {
+    private static final String TAG = GTaskManager.class.getSimpleName();  // 日志标签
+
+    // 同步状态常量
+    public static final int STATE_SUCCESS = 0;           // 同步成功
+    public static final int STATE_NETWORK_ERROR = 1;     // 网络错误
+    public static final int STATE_INTERNAL_ERROR = 2;    // 内部错误
+    public static final int STATE_SYNC_IN_PROGRESS = 3;  // 同步进行中
+    public static final int STATE_SYNC_CANCELLED = 4;    // 同步已取消
+
+    private static GTaskManager mInstance = null;
+
+    private Activity mActivity;                          // Activity上下文，用于获取授权令牌
+    private Context mContext;                            // 应用上下文
+    private ContentResolver mContentResolver;            // ContentResolver，用于数据库操作
+    private boolean mSyncing;                            // 同步状态标记
+    private boolean mCancelled;                          // 取消同步标记
+
+    // Google Task相关数据结构
+    private HashMap<String, TaskList> mGTaskListHashMap; // Google Task列表映射（GID -> TaskList）
+    private HashMap<String, Node> mGTaskHashMap;         // Google Task节点映射（GID -> Node）
+    private HashMap<String, MetaData> mMetaHashMap;      // 元数据映射（相关GID -> MetaData）
+    private TaskList mMetaList;                          // 元数据任务列表
+
+    // 本地数据相关
+    private HashSet<Long> mLocalDeleteIdMap;             // 本地待删除的便签ID集合
+    private HashMap<String, Long> mGidToNid;             // GID到本地ID的映射
+    private HashMap<Long, String> mNidToGid;             // 本地ID到GID的映射
+
+
+    //初始化所有数据结构和状态变量
+    private GTaskManager() {
+        mSyncing = false;
+        mCancelled = false;
+        mGTaskListHashMap = new HashMap<String, TaskList>();
+        mGTaskHashMap = new HashMap<String, Node>();
+        mMetaHashMap = new HashMap<String, MetaData>();
+        mMetaList = null;
+        mLocalDeleteIdMap = new HashSet<Long>();
+        mGidToNid = new HashMap<String, Long>();
+        mNidToGid = new HashMap<Long, String>();
+    }
+
+
+    public static synchronized GTaskManager getInstance() {
+        if (mInstance == null) {
+            mInstance = new GTaskManager();
+        }
+        return mInstance;
+    }
+
+
+    //设置Activity上下文
+    public synchronized void setActivityContext(Activity activity) {
+        mActivity = activity;
+    }
+
+    /**
+     * @method  sync
+     * @description 执行同步操作
+     * 1. 检查是否已经在同步中
+     * 2. 初始化同步环境和数据结构
+     * 3. 登录Google Task
+     * 4. 初始化任务列表
+     * 5. 同步内容（包括文件夹和便签）
+     * 6. 清理资源
+     * 7. 返回同步结果
+     *
+     * @param context Android上下文
+     * @param asyncTask 异步任务，用于更新进度
+     * @return 同步结果状态码
+     */
+    public int sync(Context context, GTaskASyncTask asyncTask) {
+        // 检查是否已经在同步中
+        if (mSyncing) {
+            Log.d(TAG, "Sync is in progress");
+            return STATE_SYNC_IN_PROGRESS;
+        }
+
+        // 初始化同步环境
+        mContext = context;
+        mContentResolver = mContext.getContentResolver();
+        mSyncing = true;
+        mCancelled = false;
+
+        // 清空数据结构，准备新的同步
+        mGTaskListHashMap.clear();
+        mGTaskHashMap.clear();
+        mMetaHashMap.clear();
+        mLocalDeleteIdMap.clear();
+        mGidToNid.clear();
+        mNidToGid.clear();
+
+        try {
+            GTaskClient client = GTaskClient.getInstance();
+            client.resetUpdateArray();  // 重置客户端更新数组
+
+            // 登录Google Task
+            if (!mCancelled) {
+                if (!client.login(mActivity)) {
+                    throw new NetworkFailureException("login google task failed");
+                }
+            }
+
+            // 初始化任务列表
+            asyncTask.publishProgess(mContext.getString(R.string.sync_progress_init_list));
+            initGTaskList();
+
+            // 执行内容同步
+            asyncTask.publishProgess(mContext.getString(R.string.sync_progress_syncing));
+            syncContent();
+        } catch (NetworkFailureException e) {
+            Log.e(TAG, e.toString());
+            return STATE_NETWORK_ERROR;
+        } catch (ActionFailureException e) {
+            Log.e(TAG, e.toString());
+            return STATE_INTERNAL_ERROR;
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return STATE_INTERNAL_ERROR;
+        } finally {
+            // 无论成功失败，都清理资源
+            mGTaskListHashMap.clear();
+            mGTaskHashMap.clear();
+            mMetaHashMap.clear();
+            mLocalDeleteIdMap.clear();
+            mGidToNid.clear();
+            mNidToGid.clear();
+            mSyncing = false;
+        }
+
+        return mCancelled ? STATE_SYNC_CANCELLED : STATE_SUCCESS;
+    }
+
+    /**
+     * @method  initGTaskList
+     * @description 初始化Google Task列表
+     * 执行流程：
+     * 1. 从Google Task获取所有任务列表
+     * 2. 查找并初始化元数据列表
+     * 3. 加载元数据列表中的所有元数据
+     * 4. 如果元数据列表不存在则创建
+     * 5. 初始化普通任务列表
+     */
+    private void initGTaskList() throws NetworkFailureException {
+        if (mCancelled) return;
+
+        GTaskClient client = GTaskClient.getInstance();
+        try {
+            JSONArray jsTaskLists = client.getTaskLists();
+
+            // 首先初始化元数据列表
+            mMetaList = null;
+            for (int i = 0; i < jsTaskLists.length(); i++) {
+                JSONObject object = jsTaskLists.getJSONObject(i);
+                String gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
+                String name = object.getString(GTaskStringUtils.GTASK_JSON_NAME);
+
+                // 查找元数据列表（名称以特定前缀开头）
+                if (name.equals(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META)) {
+                    mMetaList = new TaskList();
+                    mMetaList.setContentByRemoteJSON(object);
+
+                    // 加载元数据列表中的所有元数据任务
+                    JSONArray jsMetas = client.getTaskList(gid);
+                    for (int j = 0; j < jsMetas.length(); j++) {
+                        object = (JSONObject) jsMetas.getJSONObject(j);
+                        MetaData metaData = new MetaData();
+                        metaData.setContentByRemoteJSON(object);
+                        if (metaData.isWorthSaving()) {
+                            mMetaList.addChildTask(metaData);
+                            if (metaData.getGid() != null) {
+                                mMetaHashMap.put(metaData.getRelatedGid(), metaData);
+                            }
+                        }
+                    }
+                }
+            }
+
+            // 如果元数据列表不存在，创建新的
+            if (mMetaList == null) {
+                mMetaList = new TaskList();
+                mMetaList.setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META);
+                GTaskClient.getInstance().createTaskList(mMetaList);
+            }
+
+            // 初始化普通任务列表
+            for (int i = 0; i < jsTaskLists.length(); i++) {
+                JSONObject object = jsTaskLists.getJSONObject(i);
+                String gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
+                String name = object.getString(GTaskStringUtils.GTASK_JSON_NAME);
+
+                // 只处理以MIUI前缀开头的任务列表（排除元数据列表）
+                if (name.startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX)
+                        && !name.equals(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META)) {
+                    TaskList tasklist = new TaskList();
+                    tasklist.setContentByRemoteJSON(object);
+                    mGTaskListHashMap.put(gid, tasklist);
+                    mGTaskHashMap.put(gid, tasklist);
+
+                    // 加载任务列表中的所有任务
+                    JSONArray jsTasks = client.getTaskList(gid);
+                    for (int j = 0; j < jsTasks.length(); j++) {
+                        object = (JSONObject) jsTasks.getJSONObject(j);
+                        gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
+                        Task task = new Task();
+                        task.setContentByRemoteJSON(object);
+                        if (task.isWorthSaving()) {
+                            task.setMetaInfo(mMetaHashMap.get(gid));
+                            tasklist.addChildTask(task);
+                            mGTaskHashMap.put(gid, task);
+                        }
+                    }
+                }
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("initGTaskList: handing JSONObject failed");
+        }
+    }
+
+    /**
+     * @method  syncContent
+     * @description 同步内容（便签和文件夹的具体数据）
+     * 执行流程：
+     * 1. 同步本地已删除的便签
+     * 2. 同步文件夹（先同步文件夹，再同步便签）
+     * 3. 同步现有的便签
+     * 4. 处理远程新增的项目
+     * 5. 批量删除本地已删除的便签
+     * 6. 刷新本地同步ID
+     */
+    private void syncContent() throws NetworkFailureException {
+        int syncType;
+        Cursor c = null;
+        String gid;
+        Node node;
+
+        mLocalDeleteIdMap.clear();
+
+        if (mCancelled) return;
+
+        // 第一步：处理本地已删除的便签（在回收站中的便签）
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                    "(type<>? AND parent_id=?)", new String[] {
+                            String.valueOf(Notes.TYPE_SYSTEM), String.valueOf(Notes.ID_TRASH_FOLER)
+                    }, null);
+            if (c != null) {
+                while (c.moveToNext()) {
+                    gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                    node = mGTaskHashMap.get(gid);
+                    if (node != null) {
+                        mGTaskHashMap.remove(gid);
+                        doContentSync(Node.SYNC_ACTION_DEL_REMOTE, node, c);
+                    }
+
+                    mLocalDeleteIdMap.add(c.getLong(SqlNote.ID_COLUMN));
+                }
+            } else {
+                Log.w(TAG, "failed to query trash folder");
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+                c = null;
+            }
+        }
+
+        // 第二步：同步文件夹（必须先同步文件夹，因为便签需要知道父文件夹的映射关系）
+        syncFolder();
+
+        // 第三步：同步现有的便签
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                    "(type=? AND parent_id<>?)", new String[] {
+                            String.valueOf(Notes.TYPE_NOTE), String.valueOf(Notes.ID_TRASH_FOLER)
+                    }, NoteColumns.TYPE + " DESC");
+            if (c != null) {
+                while (c.moveToNext()) {
+                    gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                    node = mGTaskHashMap.get(gid);
+                    if (node != null) {
+                        mGTaskHashMap.remove(gid);
+                        mGidToNid.put(gid, c.getLong(SqlNote.ID_COLUMN));
+                        mNidToGid.put(c.getLong(SqlNote.ID_COLUMN), gid);
+                        syncType = node.getSyncAction(c);
+                    } else {
+                        if (c.getString(SqlNote.GTASK_ID_COLUMN).trim().length() == 0) {
+                            // 本地新增：本地有GID，但远程没有对应节点
+                            syncType = Node.SYNC_ACTION_ADD_REMOTE;
+                        } else {
+                            // 远程删除：本地有GID，但远程节点不存在
+                            syncType = Node.SYNC_ACTION_DEL_LOCAL;
+                        }
+                    }
+                    doContentSync(syncType, node, c);
+                }
+            } else {
+                Log.w(TAG, "failed to query existing note in database");
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+                c = null;
+            }
+        }
+
+        // 第四步：处理远程新增的项目（遍历剩余的Google Task节点）
+        Iterator<Map.Entry<String, Node>> iter = mGTaskHashMap.entrySet().iterator();
+        while (iter.hasNext()) {
+            Map.Entry<String, Node> entry = iter.next();
+            node = entry.getValue();
+            doContentSync(Node.SYNC_ACTION_ADD_LOCAL, node, null);
+        }
+
+        // 第五步：批量删除本地已删除的便签
+        if (!mCancelled) {
+            if (!DataUtils.batchDeleteNotes(mContentResolver, mLocalDeleteIdMap)) {
+                throw new ActionFailureException("failed to batch-delete local deleted notes");
+            }
+        }
+
+        // 第六步：刷新本地同步ID
+        if (!mCancelled) {
+            GTaskClient.getInstance().commitUpdate();
+            refreshLocalSyncId();
+        }
+    }
+
+    /**
+     * @method  syncFolder
+     * @description 同步文件夹
+     * 执行流程：
+     * 1. 同步根文件夹
+     * 2. 同步通话记录文件夹
+     * 3. 同步现有的普通文件夹
+     * 4. 处理远程新增的文件夹
+     */
+    private void syncFolder() throws NetworkFailureException {
+        Cursor c = null;
+        String gid;
+        Node node;
+        int syncType;
+
+        if (mCancelled) return;
+
+        // 同步根文件夹
+        try {
+            c = mContentResolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI,
+                    Notes.ID_ROOT_FOLDER), SqlNote.PROJECTION_NOTE, null, null, null);
+            if (c != null) {
+                c.moveToNext();
+                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                node = mGTaskHashMap.get(gid);
+                if (node != null) {
+                    mGTaskHashMap.remove(gid);
+                    mGidToNid.put(gid, (long) Notes.ID_ROOT_FOLDER);
+                    mNidToGid.put((long) Notes.ID_ROOT_FOLDER, gid);
+                    // 系统文件夹：只有在名称不同时才更新远程
+                    if (!node.getName().equals(
+                            GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT))
+                        doContentSync(Node.SYNC_ACTION_UPDATE_REMOTE, node, c);
+                } else {
+                    doContentSync(Node.SYNC_ACTION_ADD_REMOTE, node, c);
+                }
+            } else {
+                Log.w(TAG, "failed to query root folder");
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+                c = null;
+            }
+        }
+
+        // 同步通话记录文件夹
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE, "(_id=?)",
+                    new String[] {
+                            String.valueOf(Notes.ID_CALL_RECORD_FOLDER)
+                    }, null);
+            if (c != null) {
+                if (c.moveToNext()) {
+                    gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                    node = mGTaskHashMap.get(gid);
+                    if (node != null) {
+                        mGTaskHashMap.remove(gid);
+                        mGidToNid.put(gid, (long) Notes.ID_CALL_RECORD_FOLDER);
+                        mNidToGid.put((long) Notes.ID_CALL_RECORD_FOLDER, gid);
+                        // 系统文件夹：只有在名称不同时才更新远程
+                        if (!node.getName().equals(
+                                GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_CALL_NOTE))
+                            doContentSync(Node.SYNC_ACTION_UPDATE_REMOTE, node, c);
+                    } else {
+                        doContentSync(Node.SYNC_ACTION_ADD_REMOTE, node, c);
+                    }
+                }
+            } else {
+                Log.w(TAG, "failed to query call note folder");
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+                c = null;
+            }
+        }
+
+        // 同步现有的普通文件夹
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                    "(type=? AND parent_id<>?)", new String[] {
+                            String.valueOf(Notes.TYPE_FOLDER), String.valueOf(Notes.ID_TRASH_FOLER)
+                    }, NoteColumns.TYPE + " DESC");
+            if (c != null) {
+                while (c.moveToNext()) {
+                    gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                    node = mGTaskHashMap.get(gid);
+                    if (node != null) {
+                        mGTaskHashMap.remove(gid);
+                        mGidToNid.put(gid, c.getLong(SqlNote.ID_COLUMN));
+                        mNidToGid.put(c.getLong(SqlNote.ID_COLUMN), gid);
+                        syncType = node.getSyncAction(c);
+                    } else {
+                        if (c.getString(SqlNote.GTASK_ID_COLUMN).trim().length() == 0) {
+                            // 本地新增
+                            syncType = Node.SYNC_ACTION_ADD_REMOTE;
+                        } else {
+                            // 远程删除
+                            syncType = Node.SYNC_ACTION_DEL_LOCAL;
+                        }
+                    }
+                    doContentSync(syncType, node, c);
+                }
+            } else {
+                Log.w(TAG, "failed to query existing folder");
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+                c = null;
+            }
+        }
+
+        // 处理远程新增的文件夹
+        Iterator<Map.Entry<String, TaskList>> iter = mGTaskListHashMap.entrySet().iterator();
+        while (iter.hasNext()) {
+            Map.Entry<String, TaskList> entry = iter.next();
+            gid = entry.getKey();
+            node = entry.getValue();
+            if (mGTaskHashMap.containsKey(gid)) {
+                mGTaskHashMap.remove(gid);
+                doContentSync(Node.SYNC_ACTION_ADD_LOCAL, node, null);
+            }
+        }
+
+        if (!mCancelled)
+            GTaskClient.getInstance().commitUpdate();
+    }
+
+    /**
+     * @method  doContentSync
+     * @description 根据同步类型执行相应的同步动作
+     * @param syncType 同步类型
+     * @param node Google Task节点
+     * @param c 数据库游标
+     */
+    private void doContentSync(int syncType, Node node, Cursor c) throws NetworkFailureException {
+        if (mCancelled) return;
+
+        MetaData meta;
+        switch (syncType) {
+            case Node.SYNC_ACTION_ADD_LOCAL:
+                addLocalNode(node);
+                break;
+            case Node.SYNC_ACTION_ADD_REMOTE:
+                addRemoteNode(node, c);
+                break;
+            case Node.SYNC_ACTION_DEL_LOCAL:
+                meta = mMetaHashMap.get(c.getString(SqlNote.GTASK_ID_COLUMN));
+                if (meta != null) {
+                    GTaskClient.getInstance().deleteNode(meta);
+                }
+                mLocalDeleteIdMap.add(c.getLong(SqlNote.ID_COLUMN));
+                break;
+            case Node.SYNC_ACTION_DEL_REMOTE:
+                meta = mMetaHashMap.get(node.getGid());
+                if (meta != null) {
+                    GTaskClient.getInstance().deleteNode(meta);
+                }
+                GTaskClient.getInstance().deleteNode(node);
+                break;
+            case Node.SYNC_ACTION_UPDATE_LOCAL:
+                updateLocalNode(node, c);
+                break;
+            case Node.SYNC_ACTION_UPDATE_REMOTE:
+                updateRemoteNode(node, c);
+                break;
+            case Node.SYNC_ACTION_UPDATE_CONFLICT:
+                // 冲突处理：简单策略，使用本地更新远程
+                updateRemoteNode(node, c);
+                break;
+            case Node.SYNC_ACTION_NONE:
+                break;
+            case Node.SYNC_ACTION_ERROR:
+            default:
+                throw new ActionFailureException("unknown sync action type");
+        }
+    }
+
+    /**
+     * @method  addLocalNode
+     * @description 在本地添加节点
+     * 执行流程：
+     * 1. 根据节点类型创建SqlNote对象
+     * 2. 处理可能存在的ID冲突
+     * 3. 设置父文件夹ID
+     * 4. 提交到本地数据库
+     * 5. 更新ID映射关系
+     * 6. 更新远程元数据
+     *
+     * @param node 要在本地添加的节点
+     */
+    private void addLocalNode(Node node) throws NetworkFailureException {
+        if (mCancelled) return;
+
+        SqlNote sqlNote;
+        if (node instanceof TaskList) {
+            // 处理任务列表（文件夹）
+            if (node.getName().equals(
+                    GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT)) {
+                sqlNote = new SqlNote(mContext, Notes.ID_ROOT_FOLDER);
+            } else if (node.getName().equals(
+                    GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_CALL_NOTE)) {
+                sqlNote = new SqlNote(mContext, Notes.ID_CALL_RECORD_FOLDER);
+            } else {
+                sqlNote = new SqlNote(mContext);
+                sqlNote.setContent(node.getLocalJSONFromContent());
+                sqlNote.setParentId(Notes.ID_ROOT_FOLDER);
+            }
+        } else {
+            // 处理任务（便签）
+            sqlNote = new SqlNote(mContext);
+            JSONObject js = node.getLocalJSONFromContent();
+            try {
+                // 检查便签ID是否可用
+                if (js.has(GTaskStringUtils.META_HEAD_NOTE)) {
+                    JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+                    if (note.has(NoteColumns.ID)) {
+                        long id = note.getLong(NoteColumns.ID);
+                        if (DataUtils.existInNoteDatabase(mContentResolver, id)) {
+                            // ID已被占用，移除ID让数据库自动生成新ID
+                            note.remove(NoteColumns.ID);
+                        }
+                    }
+                }
+
+                // 检查数据ID是否可用
+                if (js.has(GTaskStringUtils.META_HEAD_DATA)) {
+                    JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+                    for (int i = 0; i < dataArray.length(); i++) {
+                        JSONObject data = dataArray.getJSONObject(i);
+                        if (data.has(DataColumns.ID)) {
+                            long dataId = data.getLong(DataColumns.ID);
+                            if (DataUtils.existInDataDatabase(mContentResolver, dataId)) {
+                                // 数据ID已被占用，移除ID
+                                data.remove(DataColumns.ID);
+                            }
+                        }
+                    }
+                }
+            } catch (JSONException e) {
+                Log.w(TAG, e.toString());
+                e.printStackTrace();
+            }
+            sqlNote.setContent(js);
+
+            // 设置父文件夹ID
+            Long parentId = mGidToNid.get(((Task) node).getParent().getGid());
+            if (parentId == null) {
+                Log.e(TAG, "cannot find task's parent id locally");
+                throw new ActionFailureException("cannot add local node");
+            }
+            sqlNote.setParentId(parentId.longValue());
+        }
+
+        // 创建本地节点
+        sqlNote.setGtaskId(node.getGid());
+        sqlNote.commit(false);
+
+        // 更新ID映射
+        mGidToNid.put(node.getGid(), sqlNote.getId());
+        mNidToGid.put(sqlNote.getId(), node.getGid());
+
+        // 更新元数据
+        updateRemoteMeta(node.getGid(), sqlNote);
+    }
+
+    /**
+     * @method  updateLocalNode
+     * @description 更新本地节点（远程更新）
+     * 执行流程：
+     * 1. 从游标创建SqlNote对象
+     * 2. 设置新的内容
+     * 3. 更新父文件夹ID
+     * 4. 提交更新（带版本验证）
+     * 5. 更新远程元数据
+     *
+     * @param node 更新后的节点
+     * @param c 数据库游标，指向要更新的本地记录
+     */
+    private void updateLocalNode(Node node, Cursor c) throws NetworkFailureException {
+        if (mCancelled) return;
+
+        SqlNote sqlNote;
+        // 更新本地便签
+        sqlNote = new SqlNote(mContext, c);
+        sqlNote.setContent(node.getLocalJSONFromContent());
+
+        // 更新父文件夹ID
+        Long parentId = (node instanceof Task) ? mGidToNid.get(((Task) node).getParent().getGid())
+                : new Long(Notes.ID_ROOT_FOLDER);
+        if (parentId == null) {
+            Log.e(TAG, "cannot find task's parent id locally");
+            throw new ActionFailureException("cannot update local node");
+        }
+        sqlNote.setParentId(parentId.longValue());
+
+        // 提交更新（带版本验证）
+        sqlNote.commit(true);
+
+        // 更新元数据
+        updateRemoteMeta(node.getGid(), sqlNote);
+    }
+
+    /**
+     * @method  addRemoteNode
+     * @description 在远程添加节点（本地新增）
+     *
+     * 执行流程：
+     * 1. 根据本地数据创建Google Task节点
+     * 2. 添加到相应的父任务列表
+     * 3. 在远程创建节点
+     * 4. 更新本地节点的GID
+     * 5. 更新ID映射关系
+     * 6. 重置本地修改标记
+     *
+     * @param node 要在远程添加的节点
+     * @param c 数据库游标，指向本地记录
+     */
+    private void addRemoteNode(Node node, Cursor c) throws NetworkFailureException {
+        if (mCancelled) return;
+
+        SqlNote sqlNote = new SqlNote(mContext, c);
+        Node n;
+
+        // 在远程创建节点
+        if (sqlNote.isNoteType()) {
+            // 创建任务（便签）
+            Task task = new Task();
+            task.setContentByLocalJSON(sqlNote.getContent());
+
+            // 查找父任务列表
+            String parentGid = mNidToGid.get(sqlNote.getParentId());
+            if (parentGid == null) {
+                Log.e(TAG, "cannot find task's parent tasklist");
+                throw new ActionFailureException("cannot add remote task");
+            }
+            mGTaskListHashMap.get(parentGid).addChildTask(task);
+
+            GTaskClient.getInstance().createTask(task);
+            n = (Node) task;
+
+            // 添加元数据
+            updateRemoteMeta(task.getGid(), sqlNote);
+        } else {
+            // 创建任务列表（文件夹）
+            TaskList tasklist = null;
+
+            // 检查是否已存在同名文件夹
+            String folderName = GTaskStringUtils.MIUI_FOLDER_PREFFIX;
+            if (sqlNote.getId() == Notes.ID_ROOT_FOLDER)
+                folderName += GTaskStringUtils.FOLDER_DEFAULT;
+            else if (sqlNote.getId() == Notes.ID_CALL_RECORD_FOLDER)
+                folderName += GTaskStringUtils.FOLDER_CALL_NOTE;
+            else
+                folderName += sqlNote.getSnippet();
+
+            // 查找已存在的同名文件夹
+            Iterator<Map.Entry<String, TaskList>> iter = mGTaskListHashMap.entrySet().iterator();
+            while (iter.hasNext()) {
+                Map.Entry<String, TaskList> entry = iter.next();
+                String gid = entry.getKey();
+                TaskList list = entry.getValue();
+
+                if (list.getName().equals(folderName)) {
+                    tasklist = list;
+                    if (mGTaskHashMap.containsKey(gid)) {
+                        mGTaskHashMap.remove(gid);
+                    }
+                    break;
+                }
+            }
+
+            // 如果没有匹配的文件夹，创建新的
+            if (tasklist == null) {
+                tasklist = new TaskList();
+                tasklist.setContentByLocalJSON(sqlNote.getContent());
+                GTaskClient.getInstance().createTaskList(tasklist);
+                mGTaskListHashMap.put(tasklist.getGid(), tasklist);
+            }
+            n = (Node) tasklist;
+        }
+
+        // 更新本地节点
+        sqlNote.setGtaskId(n.getGid());
+        sqlNote.commit(false);
+        sqlNote.resetLocalModified();  // 重置本地修改标记
+        sqlNote.commit(true);
+
+        // 更新ID映射
+        mGidToNid.put(n.getGid(), sqlNote.getId());
+        mNidToGid.put(sqlNote.getId(), n.getGid());
+    }
+
+    /**
+     * @method  updateRemoteNode
+     * @description 更新远程节点（本地更新）
+     *
+     * 执行流程：
+     * 1. 更新远程节点内容
+     * 2. 更新远程元数据
+     * 3. 如果需要，移动任务到其他任务列表
+     * 4. 重置本地修改标记
+     *
+     * @param node 要更新的节点
+     * @param c 数据库游标，指向本地记录
+     */
+    private void updateRemoteNode(Node node, Cursor c) throws NetworkFailureException {
+        if (mCancelled) return;
+
+        SqlNote sqlNote = new SqlNote(mContext, c);
+
+        // 更新远程节点
+        node.setContentByLocalJSON(sqlNote.getContent());
+        GTaskClient.getInstance().addUpdateNode(node);
+
+        // 更新元数据
+        updateRemoteMeta(node.getGid(), sqlNote);
+
+        // 如果便签被移动到其他文件夹，处理移动操作
+        if (sqlNote.isNoteType()) {
+            Task task = (Task) node;
+            TaskList preParentList = task.getParent();
+
+            String curParentGid = mNidToGid.get(sqlNote.getParentId());
+            if (curParentGid == null) {
+                Log.e(TAG, "cannot find task's parent tasklist");
+                throw new ActionFailureException("cannot update remote task");
+            }
+            TaskList curParentList = mGTaskListHashMap.get(curParentGid);
+
+            if (preParentList != curParentList) {
+                preParentList.removeChildTask(task);
+                curParentList.addChildTask(task);
+                GTaskClient.getInstance().moveTask(task, preParentList, curParentList);
+            }
+        }
+
+        // 重置本地修改标记
+        sqlNote.resetLocalModified();
+        sqlNote.commit(true);
+    }
+
+    /**
+     * @method  updateRemoteMeta
+     * @description 更新远程元数据
+     *
+     * 功能：为任务创建或更新关联的元数据
+     * 元数据包含任务ID和便签内容的关联信息
+     *
+     * @param gid 任务的Google Task ID
+     * @param sqlNote 本地便签对象
+     */
+    private void updateRemoteMeta(String gid, SqlNote sqlNote) throws NetworkFailureException {
+        if (sqlNote != null && sqlNote.isNoteType()) {
+            MetaData metaData = mMetaHashMap.get(gid);
+            if (metaData != null) {
+                // 更新现有元数据
+                metaData.setMeta(gid, sqlNote.getContent());
+                GTaskClient.getInstance().addUpdateNode(metaData);
+            } else {
+                // 创建新的元数据
+                metaData = new MetaData();
+                metaData.setMeta(gid, sqlNote.getContent());
+                mMetaList.addChildTask(metaData);
+                mMetaHashMap.put(gid, metaData);
+                GTaskClient.getInstance().createTask(metaData);
+            }
+        }
+    }
+
+
+    //同步完成后，更新本地便签的同步ID
+    private void refreshLocalSyncId() throws NetworkFailureException {
+        if (mCancelled) return;
+
+        // 重新获取最新的任务列表
+        mGTaskHashMap.clear();
+        mGTaskListHashMap.clear();
+        mMetaHashMap.clear();
+        initGTaskList();
+
+        // 更新本地同步ID
+        Cursor c = null;
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
+                    "(type<>? AND parent_id<>?)", new String[] {
+                            String.valueOf(Notes.TYPE_SYSTEM), String.valueOf(Notes.ID_TRASH_FOLER)
+                    }, NoteColumns.TYPE + " DESC");
+            if (c != null) {
+                while (c.moveToNext()) {
+                    String gid = c.getString(SqlNote.GTASK_ID_COLUMN);
+                    Node node = mGTaskHashMap.get(gid);
+                    if (node != null) {
+                        mGTaskHashMap.remove(gid);
+                        ContentValues values = new ContentValues();
+                        values.put(NoteColumns.SYNC_ID, node.getLastModified());
+                        mContentResolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI,
+                                c.getLong(SqlNote.ID_COLUMN)), values, null, null);
+                    } else {
+                        Log.e(TAG, "something is missed");
+                        throw new ActionFailureException(
+                                "some local items don't have gid after sync");
+                    }
+                }
+            } else {
+                Log.w(TAG, "failed to query local note to refresh sync id");
+            }
+        } finally {
+            if (c != null) {
+                c.close();
+                c = null;
+            }
+        }
+    }
+
+    //获取同步账户名称
+    public String getSyncAccount() {
+        return GTaskClient.getInstance().getSyncAccount().name;
+    }
+
+    
+    public void cancelSync() {
+        mCancelled = true;
+    }
+}

src/gtask/remote/GTaskSyncService.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.app.Activity;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.IBinder;
+
+
+/**
+  *
+  * @Package:        net.micode.notes.gtask.remote
+  * @ClassName:      GTaskSyncService
+  * @Description:
+  *  1. 管理Google Task同步的生命周期
+  *  2. 接收同步开始/取消的Intent命令
+  *  3. 在后台执行同步操作，避免阻塞UI线程
+  *  4. 通过广播发送同步状态和进度信息
+  */
+public class GTaskSyncService extends Service {
+    public final static String ACTION_STRING_NAME = "sync_action_type";  // Intent动作类型键
+
+    public final static int ACTION_START_SYNC = 0;      // 开始同步动作
+    public final static int ACTION_CANCEL_SYNC = 1;     // 取消同步动作
+    public final static int ACTION_INVALID = 2;         // 无效动作
+
+    public final static String GTASK_SERVICE_BROADCAST_NAME = "net.micode.notes.gtask.remote.gtask_sync_service";  // 广播名称
+
+    public final static String GTASK_SERVICE_BROADCAST_IS_SYNCING = "isSyncing";  // 是否正在同步的键
+    public final static String GTASK_SERVICE_BROADCAST_PROGRESS_MSG = "progressMsg";  // 进度消息的键
+
+    private static GTaskASyncTask mSyncTask = null;     // 同步任务实例
+    private static String mSyncProgress = "";           // 同步进度信息
+
+    /**
+     * 开始同步
+     *
+     * 执行流程：
+     * 1. 检查是否已经有同步任务在运行
+     * 2. 创建新的GTaskASyncTask异步任务
+     * 3. 设置任务完成监听器，在完成时清理资源
+     * 4. 执行异步任务，发送进度广播
+     */
+    private void startSync() {
+        // 确保只有一个同步任务在运行
+        if (mSyncTask == null) {
+            mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {
+                public void onComplete() {
+                    mSyncTask = null;        // 清理任务引用
+                    sendBroadcast("");       // 发送完成广播
+                    stopSelf();              // 停止服务自身
+                }
+            });
+            sendBroadcast("");               // 发送开始同步广播
+            mSyncTask.execute();             // 执行异步任务
+        }
+    }
+
+   //取消同步
+    private void cancelSync() {
+        if (mSyncTask != null) {
+            mSyncTask.cancelSync();
+        }
+    }
+
+    //初始化同步任务引用
+    @Override
+    public void onCreate() {
+        mSyncTask = null;
+    }
+
+
+    /**
+     * @method  onStartCommand
+     * @description 根据Intent中的动作类型执行相应的同步操作
+     * @param intent 启动服务的Intent
+     * @param flags 启动标志
+     * @param startId 启动ID
+     * @return 服务启动模式（START_STICKY表示服务被杀死后自动重启）
+     */
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        Bundle bundle = intent.getExtras();
+        if (bundle != null && bundle.containsKey(ACTION_STRING_NAME)) {
+            switch (bundle.getInt(ACTION_STRING_NAME, ACTION_INVALID)) {
+                case ACTION_START_SYNC:
+                    startSync();
+                    break;
+                case ACTION_CANCEL_SYNC:
+                    cancelSync();
+                    break;
+                default:
+                    break;
+            }
+            return START_STICKY;  // 服务被杀死后自动重启
+        }
+        return super.onStartCommand(intent, flags, startId);
+    }
+
+    //当系统内存不足时，取消同步任务以释放资源
+    @Override
+    public void onLowMemory() {
+        if (mSyncTask != null) {
+            mSyncTask.cancelSync();
+        }
+    }
+
+    //此服务不提供绑定功能，返回null
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    //发送同步状态广播
+    public void sendBroadcast(String msg) {
+        mSyncProgress = msg;
+        Intent intent = new Intent(GTASK_SERVICE_BROADCAST_NAME);
+        intent.putExtra(GTASK_SERVICE_BROADCAST_IS_SYNCING, mSyncTask != null);
+        intent.putExtra(GTASK_SERVICE_BROADCAST_PROGRESS_MSG, msg);
+        sendBroadcast(intent);
+    }
+
+
+    //设置GTaskManager的Activity上下文并启动服务
+    public static void startSync(Activity activity) {
+        GTaskManager.getInstance().setActivityContext(activity);
+        Intent intent = new Intent(activity, GTaskSyncService.class);
+        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_START_SYNC);
+        activity.startService(intent);
+    }
+
+
+    //从Context调用的便捷方法，发送取消同步命令到服务
+    public static void cancelSync(Context context) {
+        Intent intent = new Intent(context, GTaskSyncService.class);
+        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_CANCEL_SYNC);
+        context.startService(intent);
+    }
+
+    //检查是否正在同步
+
+    public static boolean isSyncing() {
+        return mSyncTask != null;
+    }
+
+    
+    public static String getProgressString() {
+        return mSyncProgress;
+    }
+}

src/model/Note.java

@@ -0,0 +1,276 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.model;
+import android.content.ContentProviderOperation;
+import android.content.ContentProviderResult;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.OperationApplicationException;
+import android.net.Uri;
+import android.os.RemoteException;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.Notes.TextNote;
+
+import java.util.ArrayList;
+
+
+/**
+ *
+ * @Package:        net.micode.notes.model
+ * @ClassName:      Note
+ * @Description:    定义了便签对象的基本操作：创建新便签、设置便签属性、同步便签等
+ */
+public class Note {
+    private ContentValues mNoteDiffValues;//用于存储便签属性的变化
+    private NoteData mNoteData;//用于存储便签的具体数据
+    private static final String TAG = "Note";
+    /**
+     * Create a new note id for adding a new note to databases
+     */
+    public static synchronized long getNewNoteId(Context context, long folderId) {
+        // Create a new note in the database
+        ContentValues values = new ContentValues();
+        long createdTime = System.currentTimeMillis();// 获取当前时间作为创建时间
+        values.put(NoteColumns.CREATED_DATE, createdTime);
+        values.put(NoteColumns.MODIFIED_DATE, createdTime);
+        values.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+        values.put(NoteColumns.LOCAL_MODIFIED, 1);
+        values.put(NoteColumns.PARENT_ID, folderId);
+        Uri uri = context.getContentResolver().insert(Notes.CONTENT_NOTE_URI, values);//获取新便签的 URI
+
+        long noteId = 0;
+        try {
+            noteId = Long.valueOf(uri.getPathSegments().get(1));// 从 URI 中提取便签 ID
+        } catch (NumberFormatException e) {
+            Log.e(TAG, "Get note id error :" + e.toString());
+            noteId = 0;
+        }
+        if (noteId == -1) {
+            throw new IllegalStateException("Wrong note id:" + noteId);
+        }
+        return noteId;
+    }
+
+    public Note() {
+        mNoteDiffValues = new ContentValues();
+        mNoteData = new NoteData();
+    }
+
+    public void setNoteValue(String key, String value) {
+        mNoteDiffValues.put(key, value);// 将便签属性的变化存储到 ContentValues 对象中
+        mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);// 标记便签为本地已修改
+        mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());// 更新修改时间
+    }
+
+    public void setTextData(String key, String value) {
+        mNoteData.setTextData(key, value);
+    }
+
+    public void setTextDataId(long id) {
+        mNoteData.setTextDataId(id);
+    }
+
+    public long getTextDataId() {
+        return mNoteData.mTextDataId;
+    }
+
+    public void setCallDataId(long id) {
+        mNoteData.setCallDataId(id);
+    }
+
+    public void setCallData(String key, String value) {
+        mNoteData.setCallData(key, value);
+    }
+
+    public boolean isLocalModified() {
+        return mNoteDiffValues.size() > 0 || mNoteData.isLocalModified();//便签属性或数据是否有本地修改
+    }
+
+    //同步便签到内容提供器中
+    public boolean syncNote(Context context, long noteId) {
+        if (noteId <= 0) {
+            throw new IllegalArgumentException("Wrong note id:" + noteId);
+        }
+
+        if (!isLocalModified()) {
+            return true;
+        }
+
+        /**
+         * In theory, once data changed, the note should be updated on {@link NoteColumns#LOCAL_MODIFIED} and
+         * {@link NoteColumns#MODIFIED_DATE}. For data safety, though update note fails, we also update the
+         * note data info
+         */
+        if (context.getContentResolver().update(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), mNoteDiffValues, null,
+                null) == 0) {
+            Log.e(TAG, "Update note error, should not happen");
+            // Do not return, fall through
+        }
+        mNoteDiffValues.clear();
+
+        if (mNoteData.isLocalModified()
+                && (mNoteData.pushIntoContentResolver(context, noteId) == null)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    //内部类：用于存储便签的具体数据
+    private class NoteData {
+        private long mTextDataId;
+
+        private ContentValues mTextDataValues;
+
+        private long mCallDataId;
+
+        private ContentValues mCallDataValues;
+
+        private static final String TAG = "NoteData";
+
+        public NoteData() {
+            mTextDataValues = new ContentValues();
+            mCallDataValues = new ContentValues();
+            mTextDataId = 0;
+            mCallDataId = 0;
+        }
+
+        boolean isLocalModified() {
+            return mTextDataValues.size() > 0 || mCallDataValues.size() > 0;
+        }
+
+        void setTextDataId(long id) {
+            if(id <= 0) {
+                throw new IllegalArgumentException("Text data id should larger than 0");
+            }
+            mTextDataId = id;
+        }
+
+        void setCallDataId(long id) {
+            if (id <= 0) {
+                throw new IllegalArgumentException("Call data id should larger than 0");
+            }
+            mCallDataId = id;
+        }
+
+        void setCallData(String key, String value) {
+            mCallDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+
+        void setTextData(String key, String value) {
+            mTextDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+
+
+         /**
+          * @method  pushIntoContentResolver
+          * @description 将便签数据（文本数据和通话数据）批量同步到Content Provider中
+          * @param context Android上下文，用于访问ContentResolver
+          * @param noteId 当前便签的唯一标识符，用于关联数据记录
+          * @return Uri 操作成功时返回便签的完整URI，失败时返回null
+          * 调用路径：
+          * WorkingNote.saveNote() → Note.syncNote() → NoteData.pushIntoContentResolver()
+          */
+        Uri pushIntoContentResolver(Context context, long noteId) {
+            /**
+             * Check for safety
+             */
+            if (noteId <= 0) {
+                throw new IllegalArgumentException("Wrong note id:" + noteId);
+            }
+
+            ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+            ContentProviderOperation.Builder builder = null;
+
+            //处理文本数据变更
+            if(mTextDataValues.size() > 0) {
+                mTextDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mTextDataId == 0) {
+                    mTextDataValues.put(DataColumns.MIME_TYPE, TextNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mTextDataValues);
+                    try {
+                        setTextDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new text data fail with noteId" + noteId);
+                        mTextDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mTextDataId));
+                    builder.withValues(mTextDataValues);
+                    operationList.add(builder.build());
+                }
+                mTextDataValues.clear();
+            }
+
+            //处理通话数据变更
+            if(mCallDataValues.size() > 0) {
+                mCallDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mCallDataId == 0) {
+                    mCallDataValues.put(DataColumns.MIME_TYPE, CallNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mCallDataValues);
+                    try {
+                        setCallDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new call data fail with noteId" + noteId);
+                        mCallDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mCallDataId));
+                    builder.withValues(mCallDataValues);
+                    operationList.add(builder.build());
+                }
+                mCallDataValues.clear();
+            }
+
+            //执行批量操作
+            if (operationList.size() > 0) {
+                try {
+                    //批量应用所有数据库操作  applyBatch()确保所有操作在单个事务中执行
+                    ContentProviderResult[] results = context.getContentResolver().applyBatch(
+                            Notes.AUTHORITY, operationList);
+                    //检查批量操作结果 成功时返回便签的完整URI
+                    return (results == null || results.length == 0 || results[0] == null) ? null
+                            : ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId);
+                } catch (RemoteException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                } catch (OperationApplicationException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                }
+            }
+            return null;
+        }
+    }
+}

src/model/WorkingNote.java

@@ -0,0 +1,400 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.model;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ContentUris;
+import android.content.Context;
+import android.database.Cursor;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.Notes.TextNote;
+import net.micode.notes.tool.ResourceParser.NoteBgResources;
+
+
+public class WorkingNote {
+    // Note for the working note
+    private Note mNote;
+    // Note Id
+    private long mNoteId;
+    // Note content
+    private String mContent;
+    // Note mode
+    private int mMode;
+
+    private long mAlertDate;
+
+    private long mModifiedDate;
+
+    private int mBgColorId;
+
+    private int mWidgetId;
+
+    private int mWidgetType;
+
+    private long mFolderId;
+
+    private Context mContext;
+
+    private static final String TAG = "WorkingNote";
+
+    private boolean mIsDeleted;
+
+    private NoteSettingChangedListener mNoteSettingStatusListener;// 设置变化监听器
+
+    //数据表查询字段投影 用于查询便签数据
+    public static final String[] DATA_PROJECTION = new String[] {
+            DataColumns.ID,
+            DataColumns.CONTENT,
+            DataColumns.MIME_TYPE,
+            DataColumns.DATA1,
+            DataColumns.DATA2,
+            DataColumns.DATA3,
+            DataColumns.DATA4,
+    };
+
+    //便签表查询字段投影 用于查询便签属性
+    public static final String[] NOTE_PROJECTION = new String[] {
+            NoteColumns.PARENT_ID,
+            NoteColumns.ALERTED_DATE,
+            NoteColumns.BG_COLOR_ID,
+            NoteColumns.WIDGET_ID,
+            NoteColumns.WIDGET_TYPE,
+            NoteColumns.MODIFIED_DATE
+    };
+
+    private static final int DATA_ID_COLUMN = 0;
+
+    private static final int DATA_CONTENT_COLUMN = 1;
+
+    private static final int DATA_MIME_TYPE_COLUMN = 2;
+
+    private static final int DATA_MODE_COLUMN = 3;
+
+    private static final int NOTE_PARENT_ID_COLUMN = 0;
+
+    private static final int NOTE_ALERTED_DATE_COLUMN = 1;
+
+    private static final int NOTE_BG_COLOR_ID_COLUMN = 2;
+
+    private static final int NOTE_WIDGET_ID_COLUMN = 3;
+
+    private static final int NOTE_WIDGET_TYPE_COLUMN = 4;
+
+    private static final int NOTE_MODIFIED_DATE_COLUMN = 5;
+
+    // New note construct 创建新便签
+    private WorkingNote(Context context, long folderId) {
+        mContext = context;
+        mAlertDate = 0;
+        mModifiedDate = System.currentTimeMillis();
+        mFolderId = folderId;
+        mNote = new Note();
+        mNoteId = 0;
+        mIsDeleted = false;
+        mMode = 0;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
+    }
+
+    // Existing note construct 加载现有便签
+    private WorkingNote(Context context, long noteId, long folderId) {
+        mContext = context;
+        mNoteId = noteId;
+        mFolderId = folderId;
+        mIsDeleted = false;
+        mNote = new Note();
+        loadNote();
+    }
+
+    //从数据库加载便签基本属性
+    private void loadNote() {
+        // 构建便签查询URI
+        Cursor cursor = mContext.getContentResolver().query(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mNoteId), NOTE_PROJECTION, null,
+                null, null);
+
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                mFolderId = cursor.getLong(NOTE_PARENT_ID_COLUMN);
+                mBgColorId = cursor.getInt(NOTE_BG_COLOR_ID_COLUMN);
+                mWidgetId = cursor.getInt(NOTE_WIDGET_ID_COLUMN);
+                mWidgetType = cursor.getInt(NOTE_WIDGET_TYPE_COLUMN);
+                mAlertDate = cursor.getLong(NOTE_ALERTED_DATE_COLUMN);
+                mModifiedDate = cursor.getLong(NOTE_MODIFIED_DATE_COLUMN);
+            }
+            cursor.close();
+        } else {
+            Log.e(TAG, "No note with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note with id " + mNoteId);
+        }
+        loadNoteData();   // 继续加载便签内容数据
+
+    }
+
+    //加载便签的内容数据
+    private void loadNoteData() {
+        Cursor cursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI, DATA_PROJECTION,
+                DataColumns.NOTE_ID + "=?", new String[] {
+                    String.valueOf(mNoteId)
+                }, null);
+
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                do {
+                    String type = cursor.getString(DATA_MIME_TYPE_COLUMN);
+                    if (DataConstants.NOTE.equals(type)) {
+                        //处理文本便签数据
+                        mContent = cursor.getString(DATA_CONTENT_COLUMN);
+                        mMode = cursor.getInt(DATA_MODE_COLUMN);
+                        mNote.setTextDataId(cursor.getLong(DATA_ID_COLUMN));
+                    } else if (DataConstants.CALL_NOTE.equals(type)) {
+                        //处理通话便签数据
+                        mNote.setCallDataId(cursor.getLong(DATA_ID_COLUMN));
+                    } else {
+                        Log.d(TAG, "Wrong note type with type:" + type);
+                    }
+                } while (cursor.moveToNext());
+            }
+            cursor.close();
+        } else {
+            Log.e(TAG, "No data with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note's data with id " + mNoteId);
+        }
+    }
+
+    //创建空便签工厂方法
+    public static WorkingNote createEmptyNote(Context context, long folderId, int widgetId,
+            int widgetType, int defaultBgColorId) {
+        WorkingNote note = new WorkingNote(context, folderId);
+        note.setBgColorId(defaultBgColorId);
+        note.setWidgetId(widgetId);
+        note.setWidgetType(widgetType);
+        return note;
+    }
+
+    //加载现有便签的工厂方法
+    public static WorkingNote load(Context context, long id) {
+        return new WorkingNote(context, id, 0);
+    }
+
+    public synchronized boolean saveNote() {
+        if (isWorthSaving()) {
+            // 新便签：创建数据库记录并获取ID
+            if (!existInDatabase()) {
+                if ((mNoteId = Note.getNewNoteId(mContext, mFolderId)) == 0) {
+                    Log.e(TAG, "Create new note fail with id:" + mNoteId);
+                    return false;
+                }
+            }
+            mNote.syncNote(mContext, mNoteId);//同步便签数据到数据库
+
+            /**
+             * Update widget content if there exist any widget of this note
+             */
+            /**
+             * 更新小部件内容
+             * 条件：
+             * 1. 有有效的小部件ID
+             * 2. 有有效的小部件类型
+             * 3. 设置了监听器
+             */
+            if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                    && mWidgetType != Notes.TYPE_WIDGET_INVALIDE
+                    && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();
+            }
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    //检查便签是否已存在于数据库中
+    public boolean existInDatabase() {
+        return mNoteId > 0;
+    }
+
+    /**
+     * 判断便签是否值得保存
+     *
+     * 不值得保存的几种情况：
+     * 1. 便签已被标记为删除
+     * 2. 新便签且内容为空
+     * 3. 已有便签但没有本地修改
+     */
+     private boolean isWorthSaving() {
+        if (mIsDeleted || (!existInDatabase() && TextUtils.isEmpty(mContent))
+                || (existInDatabase() && !mNote.isLocalModified())) {
+            return false;
+        } else {
+            return true;
+        }
+    }
+
+    public void setOnSettingStatusChangedListener(NoteSettingChangedListener l) {
+        mNoteSettingStatusListener = l;
+    }
+
+    public void setAlertDate(long date, boolean set) {
+        if (date != mAlertDate) {
+            mAlertDate = date;
+            mNote.setNoteValue(NoteColumns.ALERTED_DATE, String.valueOf(mAlertDate));
+        }
+        if (mNoteSettingStatusListener != null) {
+            mNoteSettingStatusListener.onClockAlertChanged(date, set);
+        }
+    }
+
+    //标记便签为删除状态
+    public void markDeleted(boolean mark) {
+        mIsDeleted = mark;
+        // 如果便签有关联的小部件，通知小部件更新
+        if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                && mWidgetType != Notes.TYPE_WIDGET_INVALIDE && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();
+        }
+    }
+
+    public void setBgColorId(int id) {
+        if (id != mBgColorId) {
+            mBgColorId = id;
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onBackgroundColorChanged();
+            }
+            mNote.setNoteValue(NoteColumns.BG_COLOR_ID, String.valueOf(id));
+        }
+    }
+
+    //设置清单模式
+    public void setCheckListMode(int mode) {
+        if (mMode != mode) {
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onCheckListModeChanged(mMode, mode);
+            }
+            mMode = mode;
+            mNote.setTextData(TextNote.MODE, String.valueOf(mMode));
+        }
+    }
+
+    public void setWidgetType(int type) {
+        if (type != mWidgetType) {
+            mWidgetType = type;
+            mNote.setNoteValue(NoteColumns.WIDGET_TYPE, String.valueOf(mWidgetType));
+        }
+    }
+
+    public void setWidgetId(int id) {
+        if (id != mWidgetId) {
+            mWidgetId = id;
+            mNote.setNoteValue(NoteColumns.WIDGET_ID, String.valueOf(mWidgetId));
+        }
+    }
+
+    //设置便签工作文本内容
+    public void setWorkingText(String text) {
+        if (!TextUtils.equals(mContent, text)) {
+            mContent = text;
+            mNote.setTextData(DataColumns.CONTENT, mContent);
+        }
+    }
+
+    //将普通便签转换为通话便签
+    public void convertToCallNote(String phoneNumber, long callDate) {
+        mNote.setCallData(CallNote.CALL_DATE, String.valueOf(callDate));
+        mNote.setCallData(CallNote.PHONE_NUMBER, phoneNumber);
+        mNote.setNoteValue(NoteColumns.PARENT_ID, String.valueOf(Notes.ID_CALL_RECORD_FOLDER));
+    }
+
+    public boolean hasClockAlert() {
+        return (mAlertDate > 0 ? true : false);
+    }
+
+    public String getContent() {
+        return mContent;
+    }
+
+    public long getAlertDate() {
+        return mAlertDate;
+    }
+
+    public long getModifiedDate() {
+        return mModifiedDate;
+    }
+
+    public int getBgColorResId() {
+        return NoteBgResources.getNoteBgResource(mBgColorId);
+    }
+
+    public int getBgColorId() {
+        return mBgColorId;
+    }
+
+    public int getTitleBgResId() {
+        return NoteBgResources.getNoteTitleBgResource(mBgColorId);
+    }
+
+    public int getCheckListMode() {
+        return mMode;
+    }
+
+    public long getNoteId() {
+        return mNoteId;
+    }
+
+    public long getFolderId() {
+        return mFolderId;
+    }
+
+    public int getWidgetId() {
+        return mWidgetId;
+    }
+
+    public int getWidgetType() {
+        return mWidgetType;
+    }
+
+    //便签设置变化监听器接口
+    public interface NoteSettingChangedListener {
+        /**
+         * Called when the background color of current note has just changed
+         */
+        void onBackgroundColorChanged();
+
+        /**
+         * Called when user set clock
+         */
+        void onClockAlertChanged(long date, boolean set);
+
+        /**
+         * Call when user create note from widget
+         */
+        void onWidgetChanged();
+
+        /**
+         * Call when switch between check list mode and normal mode
+         * @param oldMode is previous mode before change
+         * @param newMode is new mode
+         */
+        void onCheckListModeChanged(int oldMode, int newMode);
+    }
+}