h

h

Contact.java

@@ -0,0 +1,91 @@
+/*
+ * 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;
+
+public class Contact {
+    // 用于缓存电话号码与联系人姓名的映射关系，提高查询效率
+    private static HashMap<String, String> sContactCache;
+    // 日志标签
+    private static final String TAG = "Contact";
+
+    // 查询联系人数据库的SQL选择语句
+    // 这个复杂查询：
+    // 1. 检查电话号码是否匹配（考虑不同格式）
+    // 2. 验证数据类型是电话号码
+    // 3. 确保原始联系人存在于phone_lookup表中
+    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 = '+')";
+    /**
+     * 根据电话号码获取联系人姓名
+     *
+     * @param context 应用上下文
+     * @param phoneNumber 要查询的电话号码
+     * @return 如果找到则返回联系人姓名，否则返回null
+     */
+    public static String getContact(Context context, String phoneNumber) {
+        // 如果缓存不存在，则初始化
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+        // 如果缓存中已有结果，直接返回
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+        // 准备查询语句，将'+'替换为电话号码的最小匹配模式（处理不同格式）
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        // 查询联系人数据库
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,         // 联系人数据的内容URI
+                new String [] { Phone.DISPLAY_NAME },   // 只获取显示名称
+                selection,                  // 准备好的查询条件
+                new String[] { phoneNumber },         // 查询参数
+                null);                     // 无排序要求
+        // 处理查询结果
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                // 从第一条结果获取联系人姓名
+                String name = cursor.getString(0);
+                // 将结果缓存以备后用
+                sContactCache.put(phoneNumber, name);
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                // 始终关闭游标，避免内存泄漏
+                cursor.close();
+            }
+        } else {
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}

Notes.java

@@ -0,0 +1,279 @@
+/*
+ * 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;
+public class Notes {
+    public static final String AUTHORITY = "micode_notes";
+    public static final String TAG = "Notes";
+    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
+     * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
+     * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
+     */
+    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;
+
+    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;
+
+    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");
+
+    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
+         * <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";
+    }
+
+    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";
+    }
+
+    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>
+         */
+        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");
+    }
+
+    public static final class CallNote implements DataColumns {
+        /**
+         * Call date for this record
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CALL_DATE = DATA1;
+
+        /**
+         * Phone number for this record
+         * <P> Type: TEXT </P>
+         */
+        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");
+    }
+}

NotesDatabaseHelper.java

@@ -0,0 +1,362 @@
+/*
+ * 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;
+
+
+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;
+
+    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" +
+        ")";
+
+    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 ''" +
+        ")";
+
+    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
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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}
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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";
+
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+
+    public void createNoteTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
+        Log.d(TAG, "note table has been created");
+    }
+
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        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);
+    }
+
+    private void createSystemFolder(SQLiteDatabase db) {
+        ContentValues values = new ContentValues();
+
+        /**
+         * call record foler for call notes
+         */
+        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
+         */
+        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
+         */
+        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
+         */
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+    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");
+    }
+
+    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);
+    }
+
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    @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
+            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");
+        }
+    }
+
+    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);
+    }
+
+    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);
+    }
+
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}

NotesProvider.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.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;
+
+
+public class NotesProvider extends ContentProvider {
+    private static final UriMatcher mMatcher;
+
+    private NotesDatabaseHelper mHelper;
+
+    private static final String TAG = "NotesProvider";
+
+    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;
+
+    private static final int URI_SEARCH          = 5;
+    private static final int URI_SEARCH_SUGGEST  = 6;
+
+    static {
+        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
+    }
+
+    /**
+     * 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.
+     */
+    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 + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+        + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+        + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+        + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
+
+    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+        + " FROM " + TABLE.NOTE
+        + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
+        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+
+    @Override
+    public boolean onCreate() {
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+    @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)) {
+            case URI_NOTE:
+                c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_DATA:
+                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) {
+                    throw new IllegalArgumentException(
+                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                }
+
+                String searchString = null;
+                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);
+                    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);
+        }
+        if (c != null) {
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+
+    @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);
+                break;
+            case URI_DATA:
+                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);
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        // Notify the note uri
+        if (noteId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+        // Notify the data uri
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+        return ContentUris.withAppendedId(uri, insertedId);
+    }
+
+    @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 ";
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+                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) {
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    @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);
+                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);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    private String parseSelection(String selection) {
+        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+    }
+
+    private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+        StringBuilder sql = new StringBuilder(120);
+        sql.append("UPDATE ");
+        sql.append(TABLE.NOTE);
+        sql.append(" SET ");
+        sql.append(NoteColumns.VERSION);
+        sql.append("=" + NoteColumns.VERSION + "+1 ");
+
+        if (id > 0 || !TextUtils.isEmpty(selection)) {
+            sql.append(" WHERE ");
+        }
+        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);
+            }
+            sql.append(selectString);
+        }
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

data/Contact.java

@@ -0,0 +1,91 @@
+/*
+ * 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;
+
+public class Contact {
+    // 用于缓存电话号码与联系人姓名的映射关系，提高查询效率
+    private static HashMap<String, String> sContactCache;
+    // 日志标签
+    private static final String TAG = "Contact";
+
+    // 查询联系人数据库的SQL选择语句
+    // 这个复杂查询：
+    // 1. 检查电话号码是否匹配（考虑不同格式）
+    // 2. 验证数据类型是电话号码
+    // 3. 确保原始联系人存在于phone_lookup表中
+    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 = '+')";
+    /**
+     * 根据电话号码获取联系人姓名
+     *
+     * @param context 应用上下文
+     * @param phoneNumber 要查询的电话号码
+     * @return 如果找到则返回联系人姓名，否则返回null
+     */
+    public static String getContact(Context context, String phoneNumber) {
+        // 如果缓存不存在，则初始化
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+        // 如果缓存中已有结果，直接返回
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+        // 准备查询语句，将'+'替换为电话号码的最小匹配模式（处理不同格式）
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        // 查询联系人数据库
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,         // 联系人数据的内容URI
+                new String [] { Phone.DISPLAY_NAME },   // 只获取显示名称
+                selection,                  // 准备好的查询条件
+                new String[] { phoneNumber },         // 查询参数
+                null);                     // 无排序要求
+        // 处理查询结果
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                // 从第一条结果获取联系人姓名
+                String name = cursor.getString(0);
+                // 将结果缓存以备后用
+                sContactCache.put(phoneNumber, name);
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                // 始终关闭游标，避免内存泄漏
+                cursor.close();
+            }
+        } else {
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}

data/Notes.java

@@ -0,0 +1,279 @@
+/*
+ * 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;
+public class Notes {
+    public static final String AUTHORITY = "micode_notes";
+    public static final String TAG = "Notes";
+    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
+     * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
+     * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
+     */
+    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;
+
+    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;
+
+    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");
+
+    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
+         * <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";
+    }
+
+    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";
+    }
+
+    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>
+         */
+        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");
+    }
+
+    public static final class CallNote implements DataColumns {
+        /**
+         * Call date for this record
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CALL_DATE = DATA1;
+
+        /**
+         * Phone number for this record
+         * <P> Type: TEXT </P>
+         */
+        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");
+    }
+}

data/NotesDatabaseHelper.java

@@ -0,0 +1,378 @@
+/*
+ * 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;
+
+/**
+ * 小米便签数据库帮助类，负责数据库的创建和版本管理
+ */
+public class NotesDatabaseHelper extends SQLiteOpenHelper {
+  	// 数据库名称
+    private static final String DB_NAME = "note.db";
+	// 当前数据库版本
+    private static final int DB_VERSION = 4;
+	// 数据库表名定义接口
+    public interface TABLE {
+        public static final String NOTE = "note";  // 笔记表
+
+        public static final String DATA = "data";  // 数据表
+    }
+
+    private static final String TAG = "NotesDatabaseHelper";   // 日志标签
+
+    private static NotesDatabaseHelper mInstance;   // 单例实例
+	// 创建笔记表的SQL语句
+    private static final String CREATE_NOTE_TABLE_SQL =
+        "CREATE TABLE " + TABLE.NOTE + "(" +     
+            NoteColumns.ID + " INTEGER PRIMARY KEY," +    // 主键ID 
+            NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +   // 父ID
+            NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," + // 提醒日期
+            NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +// 背景颜色ID
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +  // 创建时间
+            NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +   // 是否有附件
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +  // 修改时间
+            NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +     // 笔记数量(针对文件夹)
+            NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +     // 内容摘要
+            NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +     // 类型(笔记/文件夹)
+            NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +   // 小部件ID
+            NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +  // 小部件类型
+            NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +      // 同步ID
+            NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +   // 本地修改标记
+            NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +   // 原始父ID
+            NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +    // Google任务ID
+            NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +    // 版本号
+        ")";
+		// 创建数据表的SQL语句
+    private static final String CREATE_DATA_TABLE_SQL =
+        "CREATE TABLE " + TABLE.DATA + "(" +
+            DataColumns.ID + " INTEGER PRIMARY KEY," +  // 主键ID
+            DataColumns.MIME_TYPE + " TEXT NOT NULL," +   // MIME类型
+            DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +		// 关联的笔记ID
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +  // 创建时间
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 修改时间
+            DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA1 + " INTEGER," +   // 通用数据列1
+            DataColumns.DATA2 + " INTEGER," +   // 通用数据列2
+            DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +   // 通用数据列3
+            DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +  // 通用数据列4
+            DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +  // 通用数据列5
+        ")";
+		// 创建数据表笔记ID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
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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}
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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
+     */
+    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";
+
+	/**
+     * 构造函数
+     */
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+	/**
+     * 创建笔记表
+     */
+    public void createNoteTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
+        Log.d(TAG, "note table has been created");
+    }
+    /**
+     * 重新创建笔记表相关的触发器
+     */
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        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 values = new ContentValues();
+
+        /**
+         * call record foler for call notes
+         */
+        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
+         */
+        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
+         */
+        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
+         */
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+    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");
+    }
+    /**
+     * 重新创建数据表相关的触发器
+     */
+    private void reCreateDataTableTriggers(SQLiteDatabase db) {
+      // 删除现有触发器
+        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");
+      // 重新创建触发器
+        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);
+    }
+
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+       // 创建数据库时调用，创建表和触发器
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
+	// 从版本1升级到版本2
+        if (oldVersion == 1) {
+            upgradeToV2(db);
+            skipV2 = true; // this upgrade including the upgrade from v2 to v3
+            oldVersion++;
+        }
+	 // 从版本2升级到版本3
+        if (oldVersion == 2 && !skipV2) {
+            upgradeToV3(db);
+            reCreateTriggers = true;
+            oldVersion++;
+        }
+	// 从版本3升级到版本4
+        if (oldVersion == 3) {
+            upgradeToV4(db);
+            oldVersion++;
+        }
+	// 如果需要，重新创建触发器
+        if (reCreateTriggers) {
+            reCreateNoteTableTriggers(db);
+            reCreateDataTableTriggers(db);
+        }
+	// 检查版本升级是否成功
+        if (oldVersion != newVersion) {
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+    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);
+    }
+
+    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);
+    }
+
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}

data/NotesProvider.java

@@ -0,0 +1,372 @@
+/*
+ * 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;
+
+/**
+ * NotesProvider 是小米便签应用的内容提供者，负责管理便签数据的访问。
+ * 它实现了对便签和便签数据的CRUD操作，并支持搜索功能。
+ */
+public class NotesProvider extends ContentProvider {
+    private static final UriMatcher mMatcher;
+
+    private NotesDatabaseHelper mHelper;
+
+    private static final String TAG = "NotesProvider";
+
+    private static final int URI_NOTE            = 1;   // 匹配所有便签
+    private static final int URI_NOTE_ITEM       = 2;   // 匹配单个便签
+    private static final int URI_DATA            = 3;  // 匹配所有便签数据
+    private static final int URI_DATA_ITEM       = 4;  // 匹配单个便签数据
+
+    private static final int URI_SEARCH          = 5;   // 匹配搜索请求
+    private static final int URI_SEARCH_SUGGEST  = 6;   // 匹配搜索建议请求
+
+    static {
+      	// 初始化URI匹配器，用于识别不同的URI请求
+        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
+    }
+
+    /**
+     * 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.
+     */
+    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 + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+        + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+        + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+        + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
+	// 便签搜索查询语句，用于搜索便签摘要中包含特定关键词的便签
+    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+        + " FROM " + TABLE.NOTE
+        + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
+        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+	    /**
+     * 初始化ContentProvider，创建数据库帮助类实例
+     * @return 初始化成功返回true，否则返回false
+     */
+    @Override
+    public boolean onCreate() {
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+    /**
+     * 查询便签数据
+     * @param uri 查询的URI
+     * @param projection 返回的列
+     * @param selection 选择条件
+     * @param selectionArgs 选择条件参数
+     * @param sortOrder 排序方式
+     * @return 返回符合条件的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)) {
+            case URI_NOTE:
+             // 查询所有便签
+                c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_NOTE_ITEM:
+            // 查询单个便签
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_DATA:
+            // 查询所有便签数据
+                c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_DATA_ITEM:
+             // 查询单个便签数据
+                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:
+            // 处理搜索请求
+                if (sortOrder != null || projection != null) {
+                    throw new IllegalArgumentException(
+                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                }
+
+                String searchString = null;
+                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 {
+                  // 执行搜索查询
+                    searchString = String.format("%%%s%%", searchString);
+                    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，当数据变化时通知观察者
+        if (c != null) {
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+    /**
+     * 插入新的便签或便签数据
+     * @param uri 插入的URI
+     * @param values 要插入的数据
+     * @return 返回插入后的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:
+            // 插入新便签
+                insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+                break;
+            case URI_DATA:
+            // 插入新便签数据
+                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);
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        // Notify the note uri
+        if (noteId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+        // Notify the data uri
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+        return ContentUris.withAppendedId(uri, insertedId);
+    }
+
+    /**
+     * 删除便签或便签数据
+     * @param uri 删除的URI
+     * @param selection 选择条件
+     * @param selectionArgs 选择条件参数
+     * @return 返回删除的行数
+     */
+    @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:
+            // 删除便签
+                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+            // 删除单个便签
+                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:
+             // 删除便签数据
+                count = db.delete(TABLE.DATA, selection, selectionArgs);
+                deleteData = true;
+                break;
+            case URI_DATA_ITEM:
+             // 删除单个便签数据
+                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);
+        }
+      // 通知数据变化
+        if (count > 0) {
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+    /**
+     * 更新便签或便签数据
+     * @param uri 更新的URI
+     * @param values 要更新的数据
+     * @param selection 选择条件
+     * @param selectionArgs 选择条件参数
+     * @return 返回更新的行数
+     */
+    @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:
+            // 更新便签
+                increaseNoteVersion(-1, selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+            // 更新单个便签
+                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:
+            // 更新便签数据
+                count = db.update(TABLE.DATA, values, selection, selectionArgs);
+                updateData = true;
+                break;
+            case URI_DATA_ITEM:
+            // 更新单个便签数据
+                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);
+        }
+	// 通知数据变化
+        if (count > 0) {
+            if (updateData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+    /**
+     * 解析选择条件，添加额外的条件
+     * @param selection 原始选择条件
+     * @return 解析后的选择条件
+     */
+    private String parseSelection(String selection) {
+        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+    }
+    /**
+     * 增加便签版本号，用于数据同步
+     * @param id 便签ID，如果为-1则更新所有符合条件的便签
+     * @param selection 选择条件
+     * @param selectionArgs 选择条件参数
+     */
+    private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+        StringBuilder sql = new StringBuilder(120);
+        sql.append("UPDATE ");
+        sql.append(TABLE.NOTE);
+        sql.append(" SET ");
+        sql.append(NoteColumns.VERSION);
+        sql.append("=" + NoteColumns.VERSION + "+1 ");
+
+        if (id > 0 || !TextUtils.isEmpty(selection)) {
+            sql.append(" WHERE ");
+        }
+        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);
+            }
+            sql.append(selectString);
+        }
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());
+    }
+
+    /**
+     * 获取URI对应的MIME类型
+     * @param uri 请求的URI
+     * @return 返回对应的MIME类型
+     */
+    @Override
+    public String getType(Uri uri) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

gtask/data/MetaData.java

@@ -0,0 +1,113 @@
+/*
+ * 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;
+
+/**
+ * 元数据实体类，继承自Task，用于存储与Google Tasks相关的元数据信息
+ * 主要处理元数据的JSON解析、关联GID管理等逻辑
+ */
+public class MetaData extends Task {
+    private final static String TAG = MetaData.class.getSimpleName();
+	// 关联的Google Tasks的GID（全局唯一标识符）
+    private String mRelatedGid = null;
+    /**
+     * 设置元数据信息
+     * @param gid 关联的Google Tasks的GID
+     * @param metaInfo 包含元数据的JSON对象
+     */
+    public void setMeta(String gid, JSONObject metaInfo) {
+        try {
+          // 在元数据JSON中添加GID头部信息
+            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
+        } catch (JSONException e) {
+            Log.e(TAG, "failed to put related gid");
+        }
+      // 将元数据JSON转为字符串存储到便签内容中
+        setNotes(metaInfo.toString());
+       // 设置元数据对应的便签名称（固定为预定义常量）
+        setName(GTaskStringUtils.META_NOTE_NAME);
+    }
+    /**
+     * 获取关联的Google Tasks的GID
+     * @return 关联的GID，若无则返回null
+     */
+    public String getRelatedGid() {
+        return mRelatedGid;
+    }
+    /**
+     * 判断元数据是否值得保存（当前逻辑：只要便签内容不为空则值得保存）
+     * @return 便签内容不为null时返回true，否则false
+     */
+    @Override
+    public boolean isWorthSaving() {
+        return getNotes() != null;
+    }
+    /**
+     * 从远程JSON数据中解析并设置元数据内容（供同步模块调用）
+     * @param js 包含远程数据的JSON对象
+     */
+    @Override
+    public void setContentByRemoteJSON(JSONObject js) {
+        super.setContentByRemoteJSON(js);   // 先调用父类解析逻辑
+        if (getNotes() != null) {
+            try {
+              // 解析便签内容中的元数据JSON
+                JSONObject metaInfo = new JSONObject(getNotes().trim());
+              // 提取关联的GID
+                mRelatedGid = metaInfo.getString(GTaskStringUtils.META_HEAD_GTASK_ID);
+            } catch (JSONException e) {
+                Log.w(TAG, "failed to get related gid");
+                mRelatedGid = null;  // 解析失败时清空GID
+            }
+        }
+    }
+    /**
+     * 本地JSON内容设置方法（禁止调用）
+     * @throws IllegalAccessError 始终抛出异常，表明该方法不允许使用
+     */
+    @Override
+    public void setContentByLocalJSON(JSONObject js) {
+        // this function should not be called
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+    }
+    /**
+     * 获取本地JSON内容方法（禁止调用）
+     * @throws IllegalAccessError 始终抛出异常，表明该方法不允许使用
+     */
+    @Override
+    public JSONObject getLocalJSONFromContent() {
+        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
+    }
+    /**
+     * 获取同步操作类型（禁止调用）
+     * @param c 数据库游标（未使用）
+     * @throws IllegalAccessError 始终抛出异常，表明该方法不允许使用
+     */
+    @Override
+    public int getSyncAction(Cursor c) {
+        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
+    }
+
+}

gtask/data/Node.java

@@ -0,0 +1,133 @@
+/*
+ * 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;
+/**
+ * 同步节点抽象类，定义同步操作的基础模型和行为
+ * 用于表示Google Tasks中的任务、列表等实体的同步状态和数据
+ */
+public abstract class Node {
+  // 同步操作类型常量定义
+    public static final int SYNC_ACTION_NONE = 0;// 无操作
+
+    public static final int SYNC_ACTION_ADD_REMOTE = 1;// 远程添加
+
+    public static final int SYNC_ACTION_ADD_LOCAL = 2;// 本地添加
+
+    public static final int SYNC_ACTION_DEL_REMOTE = 3;// 远程删除
+
+    public static final int SYNC_ACTION_DEL_LOCAL = 4;// 本地删除
+
+    public static final int SYNC_ACTION_UPDATE_REMOTE = 5;// 远程更新
+
+    public static final int SYNC_ACTION_UPDATE_LOCAL = 6;// 本地更新
+
+    public static final int SYNC_ACTION_UPDATE_CONFLICT = 7;// 更新冲突
+
+    public static final int SYNC_ACTION_ERROR = 8;// 操作错误
+ // 节点核心属性
+    private String mGid;// Google Tasks全局唯一标识符（GID
+
+    private String mName;// 节点名称（如任务标题、列表名称）
+
+    private long mLastModified;// 最后修改时间戳
+
+    private boolean mDeleted;// 是否已删除标记
+    /**
+     * 构造方法，初始化节点默认状态
+     */
+    public Node() {
+        mGid = null;
+        mName = "";
+        mLastModified = 0;
+        mDeleted = false;
+    }
+
+    // ====================== 抽象方法（子类必须实现） ======================
+
+    /**
+     * 获取创建操作的JSON数据
+     * @param actionId 操作ID，用于标识不同的创建场景
+     * @return 包含创建操作的JSON对象
+     */
+    public abstract JSONObject getCreateAction(int actionId);
+    /**
+     * 获取更新操作的JSON数据
+     * @param actionId 操作ID，用于标识不同的更新场景
+     * @return 包含更新操作的JSON对象
+     */
+    public abstract JSONObject getUpdateAction(int actionId);
+    /**
+     * 从远程JSON数据中解析并设置节点内容（供同步模块调用）
+     * @param js 包含远程数据的JSON对象
+     */
+    public abstract void setContentByRemoteJSON(JSONObject js);
+    /**
+     * 从本地JSON数据中解析并设置节点内容（供本地存储模块调用）
+     * @param js 包含本地数据的JSON对象
+     */
+    public abstract void setContentByLocalJSON(JSONObject js);
+   /**
+     * 将节点内容转换为本地存储的JSON格式
+     * @return 表示节点内容的JSON对象
+     */
+    public abstract JSONObject getLocalJSONFromContent();
+    /**
+     * 获取节点的同步操作类型（根据数据库游标数据判断）
+     * @param c 包含节点数据的数据库游标
+     * @return 同步操作类型常量（如SYNC_ACTION_ADD_LOCAL）
+     */
+    public abstract int getSyncAction(Cursor c);
+
+    // ====================== 基础属性访问方法 ======================
+
+    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;
+    }
+
+}

gtask/data/SqlData.java

@@ -0,0 +1,227 @@
+/*
+ * 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;
+
+/**
+ * 数据库数据操作类，用于处理便签数据在SQLite数据库中的CRUD操作
+ * 提供与JSON数据格式的相互转换功能
+ */
+public class SqlData {
+    private static final String TAG = SqlData.class.getSimpleName();
+
+    // 无效ID常量
+    private static final int INVALID_ID = -99999;
+
+    // 数据库查询字段投影
+    public static final String[] PROJECTION_DATA = new String[] {
+            DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1,
+            DataColumns.DATA3
+    };
+
+    // 字段索引常量
+    public static final int DATA_ID_COLUMN = 0;         // ID字段索引
+    public static final int DATA_MIME_TYPE_COLUMN = 1;  // MIME类型字段索引
+    public static final int DATA_CONTENT_COLUMN = 2;    // 内容字段索引
+    public static final int DATA_CONTENT_DATA_1_COLUMN = 3; // DATA1字段索引
+    public static final int DATA_CONTENT_DATA_3_COLUMN = 4; // DATA3字段索引
+
+    private ContentResolver mContentResolver;  // 内容解析器，用于数据库操作
+    private boolean mIsCreate;                // 标记是否是新建数据
+    private long mDataId;                     // 数据ID
+    private String mDataMimeType;             // 数据类型(MIME类型)
+    private String mDataContent;              // 数据内容
+    private long mDataContentData1;           // 数据扩展字段1
+    private String mDataContentData3;         // 数据扩展字段3
+    private ContentValues mDiffDataValues;     // 存储有变动的字段值
+
+    /**
+     * 构造函数 - 用于创建新数据
+     * @param context 上下文对象
+     */
+    public SqlData(Context context) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;                     // 标记为新数据
+        mDataId = INVALID_ID;                 // 初始化为无效ID
+        mDataMimeType = DataConstants.NOTE;   // 默认MIME类型为便签
+        mDataContent = "";                    // 内容初始化为空
+        mDataContentData1 = 0;                // 扩展字段1初始化为0
+        mDataContentData3 = "";               // 扩展字段3初始化为空
+        mDiffDataValues = new ContentValues(); // 初始化变动字段集合
+    }
+
+    /**
+     * 构造函数 - 从数据库游标加载已有数据
+     * @param context 上下文对象
+     * @param c 数据库游标
+     */
+    public SqlData(Context context, Cursor c) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;                   // 标记为已有数据
+        loadFromCursor(c);                    // 从游标加载数据
+        mDiffDataValues = new ContentValues(); // 初始化变动字段集合
+    }
+
+    /**
+     * 从数据库游标加载数据
+     * @param c 数据库游标
+     */
+    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);
+    }
+
+    /**
+     * 从JSON对象设置数据内容
+     * @param js JSON对象
+     * @throws JSONException JSON解析异常
+     */
+    public void setContent(JSONObject js) throws JSONException {
+        // 处理ID字段
+        long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID;
+        if (mIsCreate || mDataId != dataId) {
+            mDiffDataValues.put(DataColumns.ID, dataId);
+        }
+        mDataId = dataId;
+
+        // 处理MIME类型字段
+        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;
+
+        // 处理内容字段
+        String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : "";
+        if (mIsCreate || !mDataContent.equals(dataContent)) {
+            mDiffDataValues.put(DataColumns.CONTENT, dataContent);
+        }
+        mDataContent = dataContent;
+
+        // 处理DATA1字段
+        long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0;
+        if (mIsCreate || mDataContentData1 != dataContentData1) {
+            mDiffDataValues.put(DataColumns.DATA1, dataContentData1);
+        }
+        mDataContentData1 = dataContentData1;
+
+        // 处理DATA3字段
+        String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : "";
+        if (mIsCreate || !mDataContentData3.equals(dataContentData3)) {
+            mDiffDataValues.put(DataColumns.DATA3, dataContentData3);
+        }
+        mDataContentData3 = dataContentData3;
+    }
+
+    /**
+     * 将数据内容转换为JSON对象
+     * @return JSON对象
+     * @throws JSONException JSON转换异常
+     */
+    public JSONObject getContent() throws JSONException {
+        if (mIsCreate) {
+            Log.e(TAG, "数据尚未创建到数据库中");
+            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;
+    }
+
+    /**
+     * 提交数据到数据库
+     * @param noteId 关联的便签ID
+     * @param validateVersion 是否验证版本号
+     * @param version 版本号
+     */
+    public void commit(long noteId, boolean validateVersion, long version) {
+        if (mIsCreate) {
+            // 处理新建数据的情况
+            if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) {
+                mDiffDataValues.remove(DataColumns.ID);
+            }
+
+            mDiffDataValues.put(DataColumns.NOTE_ID, noteId);
+            Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues);
+            try {
+                // 从返回的URI中获取新创建的ID
+                mDataId = Long.valueOf(uri.getPathSegments().get(1));
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "获取便签ID错误:" + e.toString());
+                throw new ActionFailureException("创建便签失败");
+            }
+        } else {
+            // 处理更新已有数据的情况
+            if (mDiffDataValues.size() > 0) {
+                int result = 0;
+                if (!validateVersion) {
+                    // 不验证版本号的更新
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null);
+                } else {
+                    // 需要验证版本号的更新
+                    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, "没有更新记录，可能在同步时用户已更新便签");
+                }
+            }
+        }
+
+        // 重置状态
+        mDiffDataValues.clear();
+        mIsCreate = false;
+    }
+
+    /**
+     * 获取数据ID
+     * @return 数据ID
+     */
+    public long getId() {
+        return mDataId;
+    }
+}

gtask/data/SqlNote.java

@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * 遵循 Apache 许可证 2.0 版（"许可证"）；
+ * 除非遵守许可证，否则不得使用此文件。
+ * 您可以在以下网址获取许可证副本：
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 除非适用法律要求或书面同意，否则根据许可证分发的软件是按"原样"提供的，
+ * 不附带任何明示或暗示的保证或条件。请参阅许可证，了解管理权限和限制的具体语言。
+ */
+
+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;
+
+
+/**
+ * 便签数据库操作类
+ * 负责便签（Note）的数据库增删改查及 JSON 数据转换
+ */
+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 标识
+
+    // 便签查询投影（指定查询的数据库字段）
+    public static final String[] PROJECTION_NOTE = new String[] {
+            NoteColumns.ID,           // 便签 ID
+            NoteColumns.ALERTED_DATE, // 提醒时间
+            NoteColumns.BG_COLOR_ID,  // 背景颜色 ID
+            NoteColumns.CREATED_DATE, // 创建时间
+            NoteColumns.HAS_ATTACHMENT, // 是否有附件（0/1）
+            NoteColumns.MODIFIED_DATE, // 修改时间
+            NoteColumns.NOTES_COUNT,  // 子便签数量（用于文件夹）
+            NoteColumns.PARENT_ID,    // 父级 ID（用于层级结构）
+            NoteColumns.SNIPPET,      // 便签摘要
+            NoteColumns.TYPE,         // 类型（普通便签、文件夹、系统文件夹等）
+            NoteColumns.WIDGET_ID,    // 桌面小部件 ID
+            NoteColumns.WIDGET_TYPE,  // 小部件类型
+            NoteColumns.SYNC_ID,      // 同步 ID（用于云同步）
+            NoteColumns.LOCAL_MODIFIED, // 本地修改标记（用于同步冲突检测）
+            NoteColumns.ORIGIN_PARENT_ID, // 原始父级 ID（可能用于同步历史记录）
+            NoteColumns.GTASK_ID,     // Google Tasks ID（任务同步）
+            NoteColumns.VERSION       // 版本号（用于乐观锁）
+    };
+
+    // 投影字段索引（方便通过索引访问字段值）
+    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; // 上下文（用于获取 ContentResolver）
+    private ContentResolver mContentResolver; // 内容解析器（操作数据库）
+    private boolean mIsCreate; // 是否为新建便签（未插入数据库）
+    private long mId; // 便签 ID
+    private long mAlertDate; // 提醒时间
+    private int mBgColorId; // 背景颜色 ID（默认取系统默认值）
+    private long mCreatedDate; // 创建时间（默认当前时间）
+    private int mHasAttachment; // 是否有附件（默认无）
+    private long mModifiedDate; // 修改时间（默认当前时间）
+    private long mParentId; // 父级 ID（默认根目录）
+    private String mSnippet; // 便签摘要（默认空字符串）
+    private int mType; // 便签类型（默认普通便签）
+    private int mWidgetId; // 小部件 ID（默认无效 ID）
+    private int mWidgetType; // 小部件类型（默认无效类型）
+    private long mOriginParent; // 原始父级 ID（默认 0）
+    private long mVersion; // 版本号（用于数据版本控制）
+    private ContentValues mDiffNoteValues; // 待更新的字段值（增量更新）
+    private ArrayList<SqlData> mDataList; // 便签内容列表（普通便签包含文本、图片等子数据）
+
+    /**
+     * 构造函数（新建便签）
+     * 初始化默认值，标记为新建状态
+     */
+    public SqlNote(Context context) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true; // 标记为新建
+        mId = INVALID_ID; // 初始 ID 无效
+        mAlertDate = 0; // 无提醒时间
+        // 获取默认背景颜色 ID（来自 ResourceParser 工具类）
+        mBgColorId = ResourceParser.getDefaultBgId(context);
+        mCreatedDate = System.currentTimeMillis(); // 创建时间为当前时间
+        mHasAttachment = 0; // 初始无附件
+        mModifiedDate = System.currentTimeMillis(); // 修改时间为当前时间
+        mParentId = 0; // 父级默认为根目录
+        mSnippet = ""; // 摘要为空
+        mType = Notes.TYPE_NOTE; // 类型为普通便签
+        // 小部件 ID 设为无效值（AppWidgetManager 定义）
+        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE; // 无效小部件类型
+        mOriginParent = 0; // 原始父级默认 0
+        mVersion = 0; // 版本号初始为 0
+        mDiffNoteValues = new ContentValues(); // 初始化待更新字段集合
+        mDataList = new ArrayList<SqlData>(); // 初始化内容列表
+    }
+
+    /**
+     * 构造函数（从 Cursor 加载已有便签）
+     * @param c 数据库查询结果 Cursor
+     */
+    public SqlNote(Context context, Cursor c) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false; // 标记为已存在
+        loadFromCursor(c); // 从 Cursor 加载数据
+        mDataList = new ArrayList<SqlData>(); // 初始化内容列表
+        // 如果是普通便签，加载其子内容（文本、图片等）
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues(); // 初始化待更新字段集合
+    }
+
+    /**
+     * 构造函数（通过 ID 加载便签）
+     * @param id 便签 ID
+     */
+    public SqlNote(Context context, long id) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false; // 标记为已存在
+        loadFromCursor(id); // 通过 ID 从数据库加载数据
+        mDataList = new ArrayList<SqlData>(); // 初始化内容列表
+        // 如果是普通便签，加载其子内容
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues(); // 初始化待更新字段集合
+    }
+
+    /**
+     * 通过 ID 从数据库加载便签数据
+     * @param id 便签 ID
+     */
+    private void loadFromCursor(long id) {
+        Cursor c = null;
+        try {
+            // 查询便签表，条件为 ID 匹配
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
+                    new String[] { String.valueOf(id) }, null);
+            if (c != null) {
+                c.moveToNext(); // 移动到查询结果第一条（假设唯一）
+                loadFromCursor(c); // 从 Cursor 解析数据
+            } else {
+                Log.w(TAG, "loadFromCursor: cursor = null"); // 日志：Cursor 为空
+            }
+        } finally {
+            if (c != null)
+                c.close(); // 关闭 Cursor 释放资源
+        }
+    }
+
+    /**
+     * 从 Cursor 解析便签数据到对象属性
+     * @param c 数据库查询结果 Cursor
+     */
+    private void loadFromCursor(Cursor c) {
+        // 从 Cursor 中按投影索引获取字段值
+        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); // 加载版本号用于乐观锁
+    }
+
+    /**
+     * 加载普通便签的子内容（如文本段落、图片等）
+     * 数据存储在独立的表中，通过 note_id 关联
+     */
+    private void loadDataContent() {
+        Cursor c = null;
+        mDataList.clear(); // 清空现有内容列表
+        try {
+            // 查询便签内容表，条件为当前便签 ID
+            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"); // 日志：便签无内容
+                    return;
+                }
+                // 遍历 Cursor，创建 SqlData 对象并添加到列表
+                while (c.moveToNext()) {
+                    SqlData data = new SqlData(mContext, c);
+                    mDataList.add(data);
+                }
+            } else {
+                Log.w(TAG, "loadDataContent: cursor = null"); // 日志：Cursor 为空
+            }
+        } finally {
+            if (c != null)
+                c.close(); // 关闭 Cursor 释放资源
+        }
+    }
+
+    /**
+     * 从 JSON 对象设置便签内容（用于同步数据解析）
+     * @param js 包含便签数据的 JSON 对象
+     * @return 是否解析成功
+     */
+    public boolean setContent(JSONObject js) {
+        try {
+            // 获取便签头部数据（note 节点）
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            int type = note.getInt(NoteColumns.TYPE);
+            
+            // 系统文件夹不可修改
+            if (type == Notes.TYPE_SYSTEM) {
+                Log.w(TAG, "cannot set system folder");
+                return false;
+            } else if (type == Notes.TYPE_FOLDER) { // 文件夹类型
+                // 文件夹仅支持更新摘要和类型
+                String snippet = note.optString(NoteColumns.SNIPPET, ""); // 安全获取摘要
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    // 记录待更新的摘要字段
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet; // 更新本地摘要
+                
+                // 更新类型（如果有变化）
+                type = note.optInt(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type; // 更新本地类型
+            } else if (type == Notes.TYPE_NOTE) { // 普通便签类型
+                // 获取内容数组（data 节点）
+                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+                
+                // 解析便签基础属性
+                long id = note.optLong(NoteColumns.ID, INVALID_ID); // 安全获取 ID
+                if (mIsCreate || mId != id) {
+                    mDiffNoteValues.put(NoteColumns.ID, id); // 新建时设置 ID
+                }
+                mId = id; // 更新本地 ID
+                
+                // 解析提醒时间
+                long alertDate = note.optLong(NoteColumns.ALERTED_DATE, 0);
+                if (mIsCreate || mAlertDate != alertDate) {
+                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate);
+                }
+                mAlertDate = alertDate;
+                
+                // 解析背景颜色 ID（默认系统默认值）
+                int bgColorId = note.optInt(NoteColumns.BG_COLOR_ID, 
+                        ResourceParser.getDefaultBgId(mContext));
+                if (mIsCreate || mBgColorId != bgColorId) {
+                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId);
+                }
+                mBgColorId = bgColorId;
+                
+                // 解析创建时间（默认当前时间）
+                long createDate = note.optLong(NoteColumns.CREATED_DATE, 
+                        System.currentTimeMillis());
+                if (mIsCreate || mCreatedDate != createDate) {
+                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate);
+                }
+                mCreatedDate = createDate;
+                
+                // 解析附件标记（默认无附件）
+                int hasAttachment = note.optInt(NoteColumns.HAS_ATTACHMENT, 0);
+                if (mIsCreate || mHasAttachment != hasAttachment) {
+                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment);
+                }
+                mHasAttachment = hasAttachment;
+                
+                // 解析修改时间（默认当前时间）
+                long modifiedDate = note.optLong(NoteColumns.MODIFIED_DATE, 
+                        System.currentTimeMillis());
+                if (mIsCreate || mModifiedDate != modifiedDate) {
+                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate);
+                }
+                mModifiedDate = modifiedDate;
+                
+                // 解析父级 ID（默认根目录）
+                long parentId = note.optLong(NoteColumns.PARENT_ID, 0);
+                if (mIsCreate || mParentId != parentId) {
+                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId);
+                }
+                mParentId = parentId;
+                
+                // 解析摘要（默认空字符串）
+                String snippet = note.optString(NoteColumns.SNIPPET, "");
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+                
+                // 解析类型（默认普通便签）
+                type = note.optInt(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+                
+                // 解析小部件 ID（默认无效 ID）
+                int widgetId = note.optInt(NoteColumns.WIDGET_ID, 
+                        AppWidgetManager.INVALID_APPWIDGET_ID);
+                if (mIsCreate || mWidgetId != widgetId) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId);
+                }
+                mWidgetId = widgetId;
+                
+                // 解析小部件类型（默认无效类型）
+                int widgetType = note.optInt(NoteColumns.WIDGET_TYPE, 
+                        Notes.TYPE_WIDGET_INVALIDE);
+                if (mIsCreate || mWidgetType != widgetType) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType);
+                }
+                mWidgetType = widgetType;
+                
+                // 解析原始父级 ID（默认 0）
+                long originParent = note.optLong(NoteColumns.ORIGIN_PARENT_ID,

gtask/data/Task.java

@@ -0,0 +1,395 @@
+/*
+ * 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;
+
+/**
+ * 任务类，继承自Node基类，表示Google任务中的一个具体任务
+ * 处理任务的创建、更新、同步以及与本地数据库的交互
+ */
+public class Task extends Node {
+    private static final String TAG = Task.class.getSimpleName();
+
+    private boolean mCompleted;      // 任务是否已完成
+    private String mNotes;          // 任务备注内容
+    private JSONObject mMetaInfo;    // 元数据信息(存储本地笔记相关信息)
+    private Task mPriorSibling;     // 前一个兄弟任务(用于排序)
+    private TaskList mParent;       // 父任务列表
+
+    /**
+     * 构造函数，初始化任务对象
+     */
+    public Task() {
+        super();
+        mCompleted = false;
+        mNotes = null;
+        mPriorSibling = null;
+        mParent = null;
+        mMetaInfo = null;
+    }
+
+    /**
+     * 生成创建任务的JSON对象
+     * @param actionId 动作ID
+     * @return 包含创建任务所需数据的JSON对象
+     */
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // 设置动作类型为创建
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+            // 设置动作ID
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // 设置任务在父列表中的索引位置
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mParent.getChildTaskIndex(this));
+
+            // 构建任务实体数据
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());  // 任务名称
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_TASK);  // 实体类型为任务
+            if (getNotes() != null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());  // 任务备注
+            }
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+            // 设置父任务列表ID
+            js.put(GTaskStringUtils.GTASK_JSON_PARENT_ID, mParent.getGid());
+
+            // 设置父类型为组
+            js.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+
+            // 设置列表ID
+            js.put(GTaskStringUtils.GTASK_JSON_LIST_ID, mParent.getGid());
+
+            // 设置前一个兄弟任务ID(用于排序)
+            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("生成任务创建JSON对象失败");
+        }
+
+        return js;
+    }
+
+    /**
+     * 生成更新任务的JSON对象
+     * @param actionId 动作ID
+     * @return 包含更新任务所需数据的JSON对象
+     */
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // 设置动作类型为更新
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+            // 设置动作ID
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // 设置任务ID
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+            // 构建任务更新数据
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());  // 更新任务名称
+            if (getNotes() != null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());  // 更新任务备注
+            }
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());  // 更新删除状态
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("生成任务更新JSON对象失败");
+        }
+
+        return js;
+    }
+
+    /**
+     * 从远程JSON数据设置任务内容
+     * @param js 包含远程任务数据的JSON对象
+     */
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js != null) {
+            try {
+                // 设置任务ID
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+                // 设置最后修改时间
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+                // 设置任务名称
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+                // 设置任务备注
+                if (js.has(GTaskStringUtils.GTASK_JSON_NOTES)) {
+                    setNotes(js.getString(GTaskStringUtils.GTASK_JSON_NOTES));
+                }
+
+                // 设置删除状态
+                if (js.has(GTaskStringUtils.GTASK_JSON_DELETED)) {
+                    setDeleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_DELETED));
+                }
+
+                // 设置完成状态
+                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("从JSON对象获取任务内容失败");
+            }
+        }
+    }
+
+    /**
+     * 从本地JSON数据设置任务内容
+     * @param js 包含本地任务数据的JSON对象
+     */
+    public void setContentByLocalJSON(JSONObject js) {
+        if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)
+                || !js.has(GTaskStringUtils.META_HEAD_DATA)) {
+            Log.w(TAG, "setContentByLocalJSON: 无可用数据");
+        }
+
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+            // 验证笔记类型
+            if (note.getInt(NoteColumns.TYPE) != Notes.TYPE_NOTE) {
+                Log.e(TAG, "无效的类型");
+                return;
+            }
+
+            // 从数据数组中获取笔记内容
+            for (int i = 0; i < dataArray.length(); i++) {
+                JSONObject data = dataArray.getJSONObject(i);
+                if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                    setName(data.getString(DataColumns.CONTENT));  // 设置任务名称
+                    break;
+                }
+            }
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * 从任务内容生成本地JSON数据
+     * @return 包含本地任务数据的JSON对象
+     */
+    public JSONObject getLocalJSONFromContent() {
+        String name = getName();
+        try {
+            if (mMetaInfo == null) {
+                // 从网页创建的新任务
+                if (name == null) {
+                    Log.w(TAG, "笔记内容为空");
+                    return null;
+                }
+
+                // 构建新的JSON结构
+                JSONObject js = new JSONObject();
+                JSONObject note = new JSONObject();
+                JSONArray dataArray = new JSONArray();
+                JSONObject data = new JSONObject();
+                data.put(DataColumns.CONTENT, name);  // 设置笔记内容
+                dataArray.put(data);
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);  // 数据部分
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);  // 设置笔记类型
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);  // 笔记元信息
+                return js;
+            } else {
+                // 已同步的任务
+                JSONObject note = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+                JSONArray dataArray = mMetaInfo.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+                // 更新笔记内容
+                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;
+        }
+    }
+
+    /**
+     * 设置元数据信息
+     * @param metaData 元数据对象
+     */
+    public void setMetaInfo(MetaData metaData) {
+        if (metaData != null && metaData.getNotes() != null) {
+            try {
+                mMetaInfo = new JSONObject(metaData.getNotes());  // 从备注解析元数据
+            } catch (JSONException e) {
+                Log.w(TAG, e.toString());
+                mMetaInfo = null;
+            }
+        }
+    }
+
+    /**
+     * 获取同步动作类型
+     * @param c 数据库游标
+     * @return 同步动作类型常量
+     */
+    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, "笔记元数据似乎已被删除");
+                return SYNC_ACTION_UPDATE_REMOTE;  // 需要更新远程
+            }
+
+            if (!noteInfo.has(NoteColumns.ID)) {
+                Log.w(TAG, "远程笔记ID似乎已被删除");
+                return SYNC_ACTION_UPDATE_LOCAL;  // 需要更新本地
+            }
+
+            // 验证笔记ID是否匹配
+            if (c.getLong(SqlNote.ID_COLUMN) != noteInfo.getLong(NoteColumns.ID)) {
+                Log.w(TAG, "笔记ID不匹配");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+            // 检查本地修改状态
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // 本地无更新
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 两边都无更新
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // 将远程更新应用到本地
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // 验证任务ID
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "任务ID不匹配");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 只有本地修改
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    // 冲突情况
+                    return SYNC_ACTION_UPDATE_CONFLICT;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+        return SYNC_ACTION_ERROR;
+    }
+
+    /**
+     * 检查任务是否值得保存
+     * @return 如果有有效内容则返回true，否则返回false
+     */
+    public boolean isWorthSaving() {
+        return mMetaInfo != null || (getName() != null && getName().trim().length() > 0)
+                || (getNotes() != null && getNotes().trim().length() > 0);
+    }
+
+    // 以下是getter和setter方法
+
+    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;
+    }
+}

gtask/data/TaskList.java

@@ -0,0 +1,445 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * 遵循 Apache 许可证 2.0 版（"许可证"）；
+ * 除非遵守许可证，否则不得使用此文件。
+ * 您可以在以下网址获取许可证副本：
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 除非适用法律要求或书面同意，否则根据许可证分发的软件是按"原样"提供的，
+ * 不附带任何明示或暗示的保证或条件。请参阅许可证，了解管理权限和限制的具体语言。
+ */
+
+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;
+
+
+/**
+ * 任务列表类（对应 Google Tasks 中的任务列表概念）
+ * 负责管理一组相关的任务，并与云端同步
+ */
+public class TaskList extends Node {
+    private static final String TAG = TaskList.class.getSimpleName();
+
+    private int mIndex; // 任务列表在同步队列中的索引位置
+    private ArrayList<Task> mChildren; // 子任务列表
+
+    /**
+     * 构造函数
+     */
+    public TaskList() {
+        super(); // 调用父类构造函数
+        mChildren = new ArrayList<Task>(); // 初始化子任务列表
+        mIndex = 1; // 默认索引为 1
+    }
+
+    /**
+     * 生成创建任务列表的 JSON 操作对象
+     * @param actionId 操作 ID（用于标识同步操作）
+     * @return JSON 格式的创建操作
+     */
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // 设置操作类型为创建任务列表
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+            // 设置操作 ID
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // 设置任务列表索引
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mIndex);
+
+            // 设置实体变更内容
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName()); // 任务列表名称
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null"); // 创建者 ID
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP); // 实体类型为组
+            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;
+    }
+
+    /**
+     * 生成更新任务列表的 JSON 操作对象
+     * @param actionId 操作 ID
+     * @return JSON 格式的更新操作
+     */
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // 设置操作类型为更新任务列表
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+            // 设置操作 ID
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // 设置任务列表 ID
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+            // 设置实体变更内容
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName()); // 任务列表名称
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted()); // 是否删除
+            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;
+    }
+
+    /**
+     * 从远程 JSON 数据设置任务列表内容（用于同步）
+     * @param js 包含任务列表数据的 JSON 对象
+     */
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js != null) {
+            try {
+                // 设置任务列表 ID
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+                // 设置最后修改时间
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+                // 设置任务列表名称
+                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");
+            }
+        }
+    }
+
+    /**
+     * 从本地 JSON 数据设置任务列表内容
+     * @param js 包含本地便签数据的 JSON 对象
+     */
+    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);
+
+            if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                // 普通文件夹类型
+                String name = folder.getString(NoteColumns.SNIPPET);
+                // 添加小米便签前缀标识
+                setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + name);
+            } else if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                // 系统文件夹类型
+                if (folder.getLong(NoteColumns.ID) == Notes.ID_ROOT_FOLDER)
+                    // 根文件夹命名
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT);
+                else if (folder.getLong(NoteColumns.ID) == Notes.ID_CALL_RECORD_FOLDER)
+                    // 通话记录文件夹命名
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX
+                            + GTaskStringUtils.FOLDER_CALL_NOTE);
+                else
+                    Log.e(TAG, "invalid system folder"); // 无效系统文件夹类型
+            } else {
+                Log.e(TAG, "error type"); // 错误类型
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * 将任务列表内容转换为本地 JSON 格式
+     * @return 本地 JSON 格式的任务列表数据
+     */
+    public JSONObject getLocalJSONFromContent() {
+        try {
+            JSONObject js = new JSONObject();
+            JSONObject folder = new JSONObject();
+
+            // 处理任务列表名称（去除可能的前缀）
+            String folderName = getName();
+            if (getName().startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX))
+                folderName = folderName.substring(GTaskStringUtils.MIUI_FOLDER_PREFFIX.length(),
+                        folderName.length());
+            
+            // 设置文件夹摘要（即任务列表名称）
+            folder.put(NoteColumns.SNIPPET, folderName);
+            
+            // 根据名称判断文件夹类型（系统文件夹或普通文件夹）
+            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);
+
+            // 将文件夹数据放入主 JSON 对象
+            js.put(GTaskStringUtils.META_HEAD_NOTE, folder);
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    /**
+     * 判断同步操作类型（本地与远程数据对比）
+     * @param c 包含本地数据的 Cursor
+     * @return 同步操作类型（SYNC_ACTION_NONE-无操作，SYNC_ACTION_UPDATE_LOCAL-更新本地，SYNC_ACTION_UPDATE_REMOTE-更新远程）
+     */
+    public int getSyncAction(Cursor c) {
+        try {
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // 本地没有修改
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // 本地和远程都没有更新
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // 应用远程数据到本地
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // 本地有修改
+                // 验证 Google Tasks ID 是否匹配
+                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()) {
+                    // 只有本地修改
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    // 文件夹冲突时，默认应用本地修改
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+        return SYNC_ACTION_ERROR;
+    }
+
+    /**
+     * 获取子任务数量
+     * @return 子任务数量
+     */
+    public int getChildTaskCount() {
+        return mChildren.size();
+    }
+
+    /**
+     * 添加子任务到任务列表末尾
+     * @param task 要添加的任务
+     * @return 是否添加成功
+     */
+    public boolean addChildTask(Task task) {
+        boolean ret = false;
+        if (task != null && !mChildren.contains(task)) {
+            ret = mChildren.add(task);
+            if (ret) {
+                // 设置任务的前置兄弟任务和父任务列表
+                task.setPriorSibling(mChildren.isEmpty() ? null : mChildren
+                        .get(mChildren.size() - 1));
+                task.setParent(this);
+            }
+        }
+        return ret;
+    }
+
+    /**
+     * 在指定位置添加子任务
+     * @param task 要添加的任务
+     * @param index 指定位置索引
+     * @return 是否添加成功
+     */
+    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);
+        if (task != null && pos == -1) {
+            mChildren.add(index, task);
+
+            // 更新任务列表中的前置兄弟关系
+            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;
+    }
+
+    /**
+     * 移除子任务
+     * @param task 要移除的任务
+     * @return 是否移除成功
+     */
+    public boolean removeChildTask(Task task) {
+        boolean ret = false;
+        int index = mChildren.indexOf(task);
+        if (index != -1) {
+            ret = mChildren.remove(task);
+
+            if (ret) {
+                // 重置任务的前置兄弟和父任务列表
+                task.setPriorSibling(null);
+                task.setParent(null);
+
+                // 更新任务列表中的前置兄弟关系
+                if (index != mChildren.size()) {
+                    mChildren.get(index).setPriorSibling(
+                            index == 0 ? null : mChildren.get(index - 1));
+                }
+            }
+        }
+        return ret;
+    }
+
+    /**
+     * 移动子任务到指定位置
+     * @param task 要移动的任务
+     * @param index 目标位置索引
+     * @return 是否移动成功
+     */
+    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;
+            
+        // 先移除再添加实现移动
+        return (removeChildTask(task) && addChildTask(task, index));
+    }
+
+    /**
+     * 根据 Google Tasks ID 查找子任务
+     * @param gid 任务的 Google Tasks ID
+     * @return 找到的任务，未找到则返回 null
+     */
+    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;
+    }
+
+    /**
+     * 获取子任务在列表中的索引位置
+     * @param task 要查找的任务
+     * @return 任务的索引位置，未找到返回 -1
+     */
+    public int getChildTaskIndex(Task task) {
+        return mChildren.indexOf(task);
+    }
+
+    /**
+     * 根据索引获取子任务
+     * @param index 索引位置
+     * @return 指定位置的任务，索引无效则返回 null
+     */
+    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 Google Tasks ID 获取子任务
+     * @param gid 任务的 Google Tasks ID
+     * @return 找到的任务，未找到则返回 null
+     */
+    public Task getChilTaskByGid(String gid) {
+        for (Task task : mChildren) {
+            if (task.getGid().equals(gid))
+                return task;
+        }
+        return null;
+    }
+
+    /**
+     * 获取所有子任务列表
+     * @return 子任务列表
+     */
+    public ArrayList<Task> getChildTaskList() {
+        return this.mChildren;
+    }
+
+    /**
+     * 设置任务列表在同步队列中的索引
+     * @param index 索引值
+     */
+    public void setIndex(int index) {
+        this.mIndex = index;
+    }
+
+    /**
+     * 获取任务列表在同步队列中的索引
+     * @return 索引值
+     */
+    public int getIndex() {
+        return this.mIndex;
+    }
+}

gtask/exception/ActionFailureException.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * 遵循 Apache 许可证 2.0 版（"许可证"）；
+ * 除非遵守许可证，否则不得使用此文件。
+ * 您可以在以下网址获取许可证副本：
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 除非适用法律要求或书面同意，否则根据许可证分发的软件是按"原样"提供的，
+ * 不附带任何明示或暗示的保证或条件。请参阅许可证，了解管理权限和限制的具体语言。
+ */
+
+package net.micode.notes.gtask.exception;
+
+/**
+ * 操作失败异常类（运行时异常）
+ * 用于标识业务操作执行失败的场景（如数据解析失败、同步操作失败等）
+ */
+public class ActionFailureException extends RuntimeException {
+    private static final long serialVersionUID = 4425249765923293627L; // 序列化版本号，用于兼容反序列化
+
+    /**
+     * 无参构造函数
+     * 创建一个默认的操作失败异常
+     */
+    public ActionFailureException() {
+        super(); // 调用父类（RuntimeException）的无参构造
+    }
+
+    /**
+     * 带错误消息的构造函数
+     * @param paramString 异常消息，描述具体失败原因（如"生成任务列表 JSON 失败"）
+     */
+    public ActionFailureException(String paramString) {
+        super(paramString); // 调用父类带消息的构造函数，便于日志记录和问题定位
+    }
+
+    /**
+     * 带错误消息和根源异常的构造函数
+     * @param paramString 异常消息，描述表面失败原因
+     * @param paramThrowable 根源异常（导致当前异常的原始异常），如 JSON 解析异常
+     * 用于保留完整的异常栈信息，方便排查底层问题
+     */
+    public ActionFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable); // 调用父类带消息和 Throwable 的构造函数
+    }
+}

gtask/exception/NetworkFailureException.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * 遵循 Apache 许可证 2.0 版（"许可证"）；
+ * 除非遵守许可证，否则不得使用此文件。
+ * 您可以在以下网址获取许可证副本：
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 除非适用法律要求或书面同意，否则根据许可证分发的软件是按"原样"提供的，
+ * 不附带任何明示或暗示的保证或条件。请参阅许可证，了解管理权限和限制的具体语言。
+ */
+
+package net.micode.notes.gtask.exception;
+
+/**
+ * 网络失败异常类
+ * 用于标识与网络请求相关的异常（如连接失败、超时等）
+ */
+public class NetworkFailureException extends Exception {
+    private static final long serialVersionUID = 2107610287180234136L; // 序列化版本号
+
+    /**
+     * 无参构造函数
+     */
+    public NetworkFailureException() {
+        super(); // 调用父类（Exception）的无参构造
+    }
+
+    /**
+     * 带错误消息的构造函数
+     * @param paramString 异常消息
+     */
+    public NetworkFailureException(String paramString) {
+        super(paramString); // 调用父类带消息的构造函数
+    }
+
+    /**
+     * 带错误消息和根源异常的构造函数
+     * @param paramString 异常消息
+     * @param paramThrowable 根源异常（导致当前异常的原始异常）
+     */
+    public NetworkFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable); // 调用父类带消息和 Throwable 的构造函数
+    }
+}

gtask/remote/GTaskASyncTask.java

@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * 遵循 Apache 许可证 2.0 版（"许可证"）；
+ * 除非遵守许可证，否则不得使用此文件。
+ * 您可以在以下网址获取许可证副本：
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 除非适用法律要求或书面同意，否则根据许可证分发的软件是按"原样"提供的，
+ * 不附带任何明示或暗示的保证或条件。请参阅许可证，了解管理权限和限制的具体语言。
+ */
+
+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;
+
+/**
+ * Google Tasks 同步的异步任务类
+ * 负责在后台执行与 Google Tasks 的同步操作，并通过通知栏显示进度和结果
+ */
+public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
+
+    private static int GTASK_SYNC_NOTIFICATION_ID = 5234235; // 同步通知的唯一标识符
+
+    /**
+     * 同步完成监听器接口
+     * 用于在同步任务完成后回调通知调用者
+     */
+    public interface OnCompleteListener {
+        void onComplete(); // 同步完成时调用的方法
+    }
+
+    private Context mContext; // 应用上下文
+    private NotificationManager mNotifiManager; // 通知管理器
+    private GTaskManager mTaskManager; // Google Tasks 管理类实例
+    private OnCompleteListener mOnCompleteListener; // 同步完成监听器
+
+    /**
+     * 构造函数
+     * @param context 应用上下文
+     * @param listener 同步完成监听器
+     */
+    public GTaskASyncTask(Context context, OnCompleteListener listener) {
+        mContext = context;
+        mOnCompleteListener = listener;
+        // 获取系统通知服务
+        mNotifiManager = (NotificationManager) mContext
+                .getSystemService(Context.NOTIFICATION_SERVICE);
+        mTaskManager = GTaskManager.getInstance(); // 获取单例的任务管理器
+    }
+
+    /**
+     * 取消同步操作
+     */
+    public void cancelSync() {
+        mTaskManager.cancelSync(); // 调用任务管理器的取消同步方法
+    }
+
+    /**
+     * 发布同步进度
+     * @param message 进度消息
+     */
+    public void publishProgess(String message) {
+        publishProgress(new String[] { message }); // 调用 AsyncTask 的进度发布方法
+    }
+
+    /**
+     * 显示通知栏消息
+     * @param tickerId 通知提示文本的资源 ID
+     * @param content 通知内容
+     */
+    private void showNotification(int tickerId, String content) {
+        // 创建通知对象，设置图标、提示文本和时间戳
+        Notification notification = new Notification(R.drawable.notification, mContext
+                .getString(tickerId), System.currentTimeMillis());
+        notification.defaults = Notification.DEFAULT_LIGHTS; // 设置默认灯光效果
+        notification.flags = Notification.FLAG_AUTO_CANCEL; // 设置点击后自动取消
+
+        PendingIntent pendingIntent;
+        // 根据通知类型设置点击后的跳转意图
+        if (tickerId != R.string.ticker_success) {
+            // 非成功通知：跳转到设置页面
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesPreferenceActivity.class), 0);
+        } else {
+            // 成功通知：跳转到便签列表页面
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesListActivity.class), 0);
+        }
+
+        // 设置通知的详细信息并显示
+        notification.setLatestEventInfo(mContext, mContext.getString(R.string.app_name), content,
+                pendingIntent);
+        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);
+    }
+
+    /**
+     * 后台执行的同步操作
+     * @param unused 不使用的参数
+     * @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)));
+        // 调用任务管理器的同步方法并返回结果
+        return mTaskManager.sync(mContext, this);
+    }
+
+    /**
+     * 处理进度更新
+     * @param progress 进度消息数组
+     */
+    @Override
+    protected void onProgressUpdate(String... progress) {
+        // 显示同步中的通知
+        showNotification(R.string.ticker_syncing, progress[0]);
+        // 如果上下文是 GTaskSyncService，发送广播通知进度
+        if (mContext instanceof GTaskSyncService) {
+            ((GTaskSyncService) mContext).sendBroadcast(progress[0]);
+        }
+    }
+
+    /**
+     * 同步完成后的处理
+     * @param result 同步结果状态码
+     */
+    @Override
+    protected void onPostExecute(Integer result) {
+        // 根据同步结果显示不同的通知
+        if (result == GTaskManager.STATE_SUCCESS) {
+            // 同步成功
+            showNotification(R.string.ticker_success, mContext.getString(
+                    R.string.success_sync_account, mTaskManager.getSyncAccount()));
+            // 记录最后同步时间
+            NotesPreferenceActivity.setLastSyncTime(mContext, System.currentTimeMillis());
+        } else if (result == GTaskManager.STATE_NETWORK_ERROR) {
+            // 网络错误
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_network));
+        } else if (result == GTaskManager.STATE_INTERNAL_ERROR) {
+            // 内部错误
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_internal));
+        } else if (result == GTaskManager.STATE_SYNC_CANCELLED) {
+            // 同步取消
+            showNotification(R.string.ticker_cancel, mContext
+                    .getString(R.string.error_sync_cancelled));
+        }
+
+        // 如果设置了完成监听器，则在线程池中执行回调
+        if (mOnCompleteListener != null) {
+            new Thread(new Runnable() {
+                public void run() {
+                    mOnCompleteListener.onComplete();
+                }
+            }).start();
+        }
+    }
+}

gtask/remote/GTaskClient.java

@@ -0,0 +1,430 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * 遵循 Apache 许可证 2.0 版（"许可证"）；
+ * 除非遵守许可证，否则不得使用此文件。
+ * 您可以在以下网址获取许可证副本：
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 除非适用法律要求或书面同意，否则根据许可证分发的软件是按"原样"提供的，
+ * 不附带任何明示或暗示的保证或条件。请参阅许可证，了解管理权限和限制的具体语言。
+ */
+
+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;
+
+
+/**
+ * Google Tasks 客户端类
+ * 负责与 Google Tasks 服务进行网络通信，实现任务和任务列表的增删改查及同步
+ */
+public class GTaskClient {
+    private static final String TAG = GTaskClient.class.getSimpleName();
+
+    private static final String GTASK_URL = "https://mail.google.com/tasks/"; // Google Tasks 根 URL
+    private static final String GTASK_GET_URL = "https://mail.google.com/tasks/ig"; // GET 请求 URL（获取数据）
+    private static final String GTASK_POST_URL = "https://mail.google.com/tasks/r/ig"; // POST 请求 URL（提交操作）
+
+    private static GTaskClient mInstance = null; // 单例实例
+
+    private DefaultHttpClient mHttpClient; // HTTP 客户端
+    private String mGetUrl; // 当前 GET 请求 URL（支持自定义域名）
+    private String mPostUrl; // 当前 POST 请求 URL（支持自定义域名）
+    private long mClientVersion; // Google Tasks 客户端版本号（用于协议兼容）
+    private boolean mLoggedin; // 登录状态
+    private long mLastLoginTime; // 最后登录时间（用于超时管理）
+    private int mActionId; // 操作 ID 生成器（保证每次请求唯一）
+    private Account mAccount; // 当前同步的 Google 账号
+    private JSONArray mUpdateArray; // 待提交的批量更新操作列表
+
+    /**
+     * 构造函数（私有化，单例模式）
+     */
+    private GTaskClient() {
+        mHttpClient = null;
+        mGetUrl = GTASK_GET_URL;
+        mPostUrl = GTASK_POST_URL;
+        mClientVersion = -1; // 初始版本号无效
+        mLoggedin = false; // 初始未登录
+        mLastLoginTime = 0; // 初始无登录时间
+        mActionId = 1; // 操作 ID 从 1 开始
+        mAccount = null; // 初始无账号
+        mUpdateArray = null; // 初始无待更新操作
+    }
+
+    /**
+     * 获取单例实例
+     * @return GTaskClient 实例
+     */
+    public static synchronized GTaskClient getInstance() {
+        if (mInstance == null) {
+            mInstance = new GTaskClient();
+        }
+        return mInstance;
+    }
+
+    /**
+     * 登录 Google 账号并初始化 Tasks 客户端
+     * @param activity 调用登录的 Activity（用于获取账号令牌）
+     * @return 是否登录成功
+     */
+    public boolean login(Activity activity) {
+        // 登录状态检查：超过 5 分钟或账号变更则重新登录
+        final long interval = 1000 * 60 * 5; // 5 分钟超时时间
+        if (mLastLoginTime + interval < System.currentTimeMillis()) {
+            mLoggedin = false;
+        }
+        if (mLoggedin && !TextUtils.equals(getSyncAccount().name, 
+                NotesPreferenceActivity.getSyncAccountName(activity))) {
+            mLoggedin = false;
+        }
+
+        if (mLoggedin) {
+            Log.d(TAG, "already logged in");
+            return true; // 已登录且账号有效，直接返回
+        }
+
+        mLastLoginTime = System.currentTimeMillis(); // 更新最后登录时间
+        String authToken = loginGoogleAccount(activity, false); // 获取 Google 账号令牌
+        if (authToken == null) {
+            Log.e(TAG, "login google account failed");
+            return false;
+        }
+
+        // 处理自定义域名账号（非 @gmail.com 或 @googlemail.com）
+        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"; // 拼接自定义 GET URL
+            mPostUrl = url.toString() + "r/ig"; // 拼接自定义 POST URL
+
+            if (tryToLoginGtask(activity, authToken)) { // 尝试登录 Tasks
+                mLoggedin = true;
+            }
+        }
+
+        // 处理官方域名账号（默认情况）
+        if (!mLoggedin) {
+            mGetUrl = GTASK_GET_URL;
+            mPostUrl = GTASK_POST_URL;
+            if (!tryToLoginGtask(activity, authToken)) { // 再次尝试登录
+                return false;
+            }
+        }
+
+        mLoggedin = true; // 登录成功
+        return true;
+    }
+
+    /**
+     * 登录 Google 账号获取认证令牌
+     * @param activity Activity 上下文
+     * @param invalidateToken 是否失效现有令牌（用于重试场景）
+     * @return 认证令牌，失败返回 null
+     */
+    private String loginGoogleAccount(Activity activity, boolean invalidateToken) {
+        String authToken;
+        AccountManager accountManager = AccountManager.get(activity);
+        Account[] accounts = accountManager.getAccountsByType("com.google"); // 获取所有 Google 账号
+
+        if (accounts.length == 0) {
+            Log.e(TAG, "there is no available google account");
+            return null;
+        }
+
+        // 获取设置中配置的同步账号
+        String accountName = NotesPreferenceActivity.getSyncAccountName(activity);
+        Account account = null;
+        for (Account a : accounts) {
+            if (a.name.equals(accountName)) {
+                account = a;
+                break;
+            }
+        }
+        if (account == null) {
+            Log.e(TAG, "unable to get an account with the same name in the settings");
+            return null;
+        }
+        mAccount = account; // 保存当前账号
+
+        // 获取认证令牌
+        AccountManagerFuture<Bundle> accountManagerFuture = accountManager.getAuthToken(account,
+                "goanna_mobile", null, activity, null, null);
+        try {
+            Bundle authTokenBundle = accountManagerFuture.getResult();
+            authToken = authTokenBundle.getString(AccountManager.KEY_AUTHTOKEN);
+            if (invalidateToken) {
+                // 失效现有令牌并重新获取（用于处理令牌过期）
+                accountManager.invalidateAuthToken("com.google", authToken);
+                loginGoogleAccount(activity, false);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "get auth token failed");
+            authToken = null;
+        }
+
+        return authToken;
+    }
+
+    /**
+     * 尝试登录 Google Tasks 服务
+     * @param activity Activity 上下文
+     * @param authToken Google 认证令牌
+     * @return 是否登录成功
+     */
+    private boolean tryToLoginGtask(Activity activity, String authToken) {
+        if (!loginGtask(authToken)) { // 首次登录失败
+            // 重新获取令牌并再次尝试
+            authToken = loginGoogleAccount(activity, true);
+            if (authToken == null) {
+                Log.e(TAG, "login google account failed");
+                return false;
+            }
+            if (!loginGtask(authToken)) { // 再次登录失败
+                Log.e(TAG, "login gtask failed");
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * 使用认证令牌登录 Google Tasks 服务
+     * @param authToken Google 认证令牌
+     * @return 是否登录成功
+     */
+    private boolean loginGtask(String authToken) {
+        int timeoutConnection = 10000; // 连接超时 10 秒
+        int timeoutSocket = 15000; // 套接字超时 15 秒
+        HttpParams httpParameters = new BasicHttpParams();
+        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
+        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
+        mHttpClient = new DefaultHttpClient(httpParameters); // 创建带超时配置的 HTTP 客户端
+        BasicCookieStore localBasicCookieStore = new BasicCookieStore();
+        mHttpClient.setCookieStore(localBasicCookieStore); // 使用内存 Cookie 存储
+        HttpProtocolParams.setUseExpectContinue(mHttpClient.getParams(), false);
+
+        try {
+            // 构造登录 URL（携带认证令牌）
+            String loginUrl = mGetUrl + "?auth=" + authToken;
+            HttpGet httpGet = new HttpGet(loginUrl);
+            HttpResponse response = mHttpClient.execute(httpGet); // 发送 GET 请求
+
+            // 检查响应中的认证 Cookie
+            List<Cookie> cookies = mHttpClient.getCookieStore().getCookies();
+            boolean hasAuthCookie = false;
+            for (Cookie cookie : cookies) {
+                if (cookie.getName().contains("GTL")) { // GTL Cookie 是 Tasks 认证标识
+                    hasAuthCookie = true;
+                }
+            }
+            if (!hasAuthCookie) {
+                Log.w(TAG, "it seems that there is no auth cookie");
+            }
+
+            // 解析响应获取客户端版本号
+            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"); // 保存客户端版本号
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return false;
+        } catch (Exception e) {
+            Log.e(TAG, "httpget gtask_url failed");
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * 生成唯一操作 ID（自增计数器）
+     * @return 操作 ID
+     */
+    private int getActionId() {
+        return mActionId++;
+    }
+
+    /**
+     * 创建 POST 请求对象（通用方法）
+     * @return HttpPost 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"); // 可能用于标识请求类型或版本
+        return httpPost;
+    }
+
+    /**
+     * 解析 HTTP 响应内容（处理压缩格式）
+     * @param entity HTTP 实体对象
+     * @return 响应内容字符串
+     * @throws IOException 输入输出异常
+     */
+    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();
+        // 处理 GZIP 压缩响应
+        if (contentEncoding != null && contentEncoding.equalsIgnoreCase("gzip")) {
+            input = new GZIPInputStream(entity.getContent());
+        // 处理 DEFLATE 压缩响应
+        } else if (contentEncoding != null && contentEncoding.equalsIgnoreCase("deflate")) {
+            Inflater inflater = new Inflater(true);
+            input = new InflaterInputStream(entity.getContent(), inflater);
+        }
+
+        try {
+            // 读取响应内容为字符串
+            InputStreamReader isr = new InputStreamReader(input);
+            BufferedReader br = new BufferedReader(isr);
+            StringBuilder sb = new StringBuilder();
+            String buff;
+            while ((buff = br.readLine()) != null) {
+                sb.append(buff);
+            }
+            return sb.toString();
+        } finally {
+            input.close(); // 确保流关闭
+        }
+    }
+
+    /**
+     * 发送 POST 请求并解析 JSON 响应
+     * @param js 请求体 JSON 对象
+     * @return 响应 JSON 对象
+     * @throws NetworkFailureException 网络异常
+     */
+    private JSONObject postRequest(JSONObject js) throws NetworkFailureException {
+        if (!mLoggedin) {
+            Log.e(TAG, "please login first");
+            throw new ActionFailureException("not logged in"); // 未登录时抛出异常
+        }
+
+        HttpPost httpPost = createHttpPost();
+        try {
+            // 构造 POST 请求参数（将 JSON 放入请求体）
+            LinkedList<BasicNameValuePair> list = new LinkedList<>();
+            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); // 解析响应为 JSON
+
+        } catch (ClientProtocolException e) {
+            Log.e(TAG, e.toString());
+            throw new NetworkFailureException("postRequest failed"); // 协议异常（网络问题）
+        } catch (IOException e) {
+            Log.e(TAG, e.toString());
+            throw new NetworkFailureException("postRequest failed"); // 输入输出异常（网络问题）
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            throw new ActionFailureException("unable to convert response content to jsonobject"); // JSON 解析失败（数据格式问题）
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            throw new ActionFailureException("error occurs when posting request"); // 其他异常
+        }
+    }
+
+    /**
+     * 创建任务（调用 Google Tasks API）
+     * @param task 要创建的任务对象
+     * @throws NetworkFailureException 网络异常
+     */
+    public void createTask(Task task) throws NetworkFailureException {
+        commitUpdate(); // 提交之前的批量操作（如果有）
+        try {
+            JSONObject jsPost = new JSONObject();
+            JSONArray actionList = new JSONArray();
+
+            // 添加创建任务的操作到请求中
+            actionList.put(task.getCreateAction(getActionId()));
+            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);
+            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion); // 携带客户端版本号
+
+            // 发送请求并解析响应
+            JSONObject jsResponse = postRequest(jsPost);
+            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(
+                    GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
+            task.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID)); // 保存任务的 Google ID
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            throw new ActionFailureException("create task: handing jsonobject failed");
+        }
+    }
+
+    /**
+     * 创建任务列表（调用 Google Tasks API）
+     * @param tasklist 要创建的任务列表对象
+     * @throws NetworkFailureException 网络异常
+     */
+    public void createTaskList(TaskList tasklist) throws NetworkFailureException {
+        commitUpdate(); // 提交之前的批量操作
+        try {
+            JSONObject jsPost = new JSONObject