111

src/Contact.java

@@ -0,0 +1,80 @@
+/*
+ * Contact 类用于通过电话号码查询联系人信息。
+ * 该类实现了从联系人数据库中获取与特定电话号码相关联的显示名称。
+ */
+
+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 {
+    // 缓存已查询过的电话号码和对应的联系人名称，以减少数据库查询次数。
+    private static HashMap<String, String> sContactCache;
+    private static final String TAG = "Contact"; // 日志标签
+
+    // 用于查询具有完整国际号码格式的电话号码的selection字符串。
+    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名称。
+     *
+     * @param context     上下文对象，用于访问内容解析器。
+     * @param phoneNumber 需要查询的电话号码。
+     * @return 与电话号码相关联的联系人名称，如果找不到则返回null。
+     */
+    public static String getContact(Context context, String phoneNumber) {
+        // 初始化或获取联系人缓存
+        if (sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+
+        // 从缓存中直接获取联系人名称，如果存在。
+        if (sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+
+        // 使用PhoneNumberUtils将电话号码格式化为适合查询的形式
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+
+        // 执行查询以获取与电话号码相关联的联系人名称
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,
+                new String[]{Phone.DISPLAY_NAME},
+                selection,
+                new String[]{phoneNumber},
+                null);
+
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                // 从查询结果中获取联系人名称并加入缓存
+                String name = cursor.getString(0);
+                sContactCache.put(phoneNumber, name);
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+                // 处理查询结果异常
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                // 关闭游标
+                cursor.close();
+            }
+        } else {
+            // 如果查询无结果，记录日志
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}

src/Notes.java

@@ -0,0 +1,273 @@
+/*
+ * 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;
+
+// Notes类定义了与笔记和文件夹相关的常量和数据列接口
+public class Notes {
+    public static final String AUTHORITY = "micode_notes"; // 用于标识内容提供者的授权名称
+    public static final String TAG = "Notes"; // 日志标签
+    public static final int TYPE_NOTE = 0; // 笔记类型
+    public static final int TYPE_FOLDER = 1; // 文件夹类型
+    public static final int TYPE_SYSTEM = 2; // 系统类型
+
+    /**
+     * 下面的ID是系统文件夹的标识符
+     * {@link Notes#ID_ROOT_FOLDER} 是默认文件夹
+     * {@link Notes#ID_TEMPARAY_FOLDER} 是属于没有文件夹的笔记
+     * {@link Notes#ID_CALL_RECORD_FOLDER} 是用于存储通话记录的
+     */
+    public static final int ID_ROOT_FOLDER = 0; // 根文件夹ID
+    public static final int ID_TEMPARAY_FOLDER = -1; // 临时文件夹ID，用于存放不属于任何文件夹的笔记
+    public static final int ID_CALL_RECORD_FOLDER = -2; // 通话记录文件夹ID
+    public static final int ID_TRASH_FOLER = -3; // 垃圾箱文件夹ID
+
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date"; // 用于Intent的提醒日期额外数据
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id"; // 笔记背景色ID
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id"; // 小部件ID
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type"; // 小部件类型
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id"; // 文件夹ID
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date"; // 通话日期
+
+    public static final int TYPE_WIDGET_INVALIDE = -1; // 无效的小部件类型
+    public static final int TYPE_WIDGET_2X = 0; // 2x小部件类型
+    public static final int TYPE_WIDGET_4X = 1; // 4x小部件类型
+
+    public static class DataConstants {
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE; // 笔记的内容项类型
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE; // 通话记录的内容项类型
+    }
+
+    /**
+     * 查询所有笔记和文件夹的Uri
+     */
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+
+    /**
+     * 查询数据的Uri
+     */
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+
+    // 笔记和文件夹的公共列接口
+    public interface NoteColumns {
+        /**
+         * 行的唯一ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * 笔记或文件夹的父ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String PARENT_ID = "parent_id";
+
+        /**
+         * 创建日期
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * 最后修改日期
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+        /**
+         * 提醒日期
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String ALERTED_DATE = "alert_date";
+
+        /**
+         * 笔记或文件夹的摘要信息
+         * <P>类型: TEXT</P>
+         */
+        public static final String SNIPPET = "snippet";
+
+        /**
+         * 笔记的小部件ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String WIDGET_ID = "widget_id";
+
+        /**
+         * 笔记的小部件类型
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String WIDGET_TYPE = "widget_type";
+
+        /**
+         * 笔记的背景色ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String BG_COLOR_ID = "bg_color_id";
+
+        /**
+         * 笔记是否有附件
+         * <P>类型: INTEGER</P>
+         */
+        public static final String HAS_ATTACHMENT = "has_attachment";
+
+        /**
+         * 笔记数量
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String NOTES_COUNT = "notes_count";
+
+        /**
+         * 文件夹类型：0-笔记，1-文件夹
+         * <P>类型: INTEGER</P>
+         */
+        public static final String TYPE = "type";
+
+        /**
+         * 最后同步ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String SYNC_ID = "sync_id";
+
+        /**
+         * 标记本地是否已修改
+         * <P>类型: INTEGER</P>
+         */
+        public static final String LOCAL_MODIFIED = "local_modified";
+
+        /**
+         * 移入临时文件夹前的原始父ID
+         * <P>类型: INTEGER</P>
+         */
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";
+
+        /**
+         * Google任务ID
+         * <P>类型: TEXT</P>
+         */
+        public static final String GTASK_ID = "gtask_id";
+
+        /**
+         * 版本号
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String VERSION = "version";
+    }
+
+    // 数据列接口
+    public interface DataColumns {
+        /**
+         * 行的唯一ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * 该项的MIME类型。
+         * <P>类型: TEXT</P>
+         */
+        public static final String MIME_TYPE = "mime_type";
+
+        /**
+         * 属于的笔记的引用ID
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String NOTE_ID = "note_id";
+
+        /**
+         * 创建日期
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * 最后修改日期
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+        /**
+         * 数据内容
+         * <P>类型: TEXT</P>
+         */
+        public static final String CONTENT = "content";
+
+        /**
+         * 通用数据列，具体含义由{@link #MIME_TYPE}决定，用于存储整型数据
+         * <P>类型: INTEGER</P>
+         */
+        public static final String DATA1 = "data1";
+
+        /**
+         * 通用数据列，具体含义由{@link #MIME_TYPE}决定，用于存储整型数据
+         * <P>类型: INTEGER</P>
+         */
+        public static final String DATA2 = "data2";
+
+        /**
+         * 通用数据列，具体含义由{@link #MIME_TYPE}决定，用于存储文本数据
+         * <P>类型: TEXT</P>
+         */
+        public static final String DATA3 = "data3";
+
+        /**
+         * 通用数据列，具体含义由{@link #MIME_TYPE}决定，用于存储文本数据
+         * <P>类型: TEXT</P>
+         */
+        public static final String DATA4 = "data4";
+
+        /**
+         * 通用数据列，具体含义由{@link #MIME_TYPE}决定，用于存储文本数据
+         * <P>类型: TEXT</P>
+         */
+        public static final String DATA5 = "data5";
+    }
+
+    // 文本笔记类，实现了DataColumns接口
+    public static final class TextNote implements DataColumns {
+        /**
+         * 模式，指示文本是否在检查列表模式中
+         * <P>类型: INTEGER 1:检查列表模式 0: 正常模式</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"; // MIME类型定义
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note"; // 单项MIME类型定义
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note"); // 内容URI定义
+    }
+
+    // 通话记录笔记类，实现了DataColumns接口
+    public static final class CallNote implements DataColumns {
+        /**
+         * 通话日期
+         * <P>类型: INTEGER (long)</P>
+         */
+        public static final String CALL_DATE = DATA1;
+
+        /**
+         * 电话号码
+         * <P>类型: TEXT</P>
+         */
+        public static final String PHONE_NUMBER = DATA3;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note"; // MIME类型定义
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note"; // 单项MIME类型定义
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note"); // 内容URI定义
+    }
+}

src/NotesDatabaseHelper.java

@@ -0,0 +1,381 @@
+/*
+ * 该类为Notes数据库的辅助类，负责管理数据库的创建和版本管理。
+ */
+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 {
+    // 数据库名称··
+    private static final String DB_NAME = "note.db";
+
+    // 数据库版本号
+    private static final int DB_VERSION = 4;
+
+    // 表接口，定义了数据库中的两个表名
+    public interface TABLE {
+        public static final String NOTE = "note";
+
+        public static final String DATA = "data";
+    }
+
+    // 日志标签
+    private static final String TAG = "NotesDatabaseHelper";
+
+    // 单例模式，确保数据库辅助类的唯一实例
+    private static NotesDatabaseHelper mInstance;
+
+    // 创建NOTE表的SQL语句
+    private static final String CREATE_NOTE_TABLE_SQL =
+            "CREATE TABLE " + TABLE.NOTE + "(" +
+                    NoteColumns.ID + " INTEGER PRIMARY KEY," +
+                    NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+                    NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+                    NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +
+                    NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +
+                    NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
+                    NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
+                    ")";
+
+    // 创建DATA表的SQL语句
+    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 ''" +
+                    ")";
+
+    // 创建DATA表的NOTE_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 + ");";
+
+    // 当更新NOTE表中的PARENT_ID字段时，增加目标文件夹的NOTE_COUNT
+    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";
+
+    // 当从文件夹移动NOTE时，减少源文件夹的NOTE_COUNT
+    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";
+
+    // 当插入新NOTE时，增加目标文件夹的NOTE_COUNT
+    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";
+
+    // 当删除NOTE时，减少文件夹的NOTE_COUNT
+    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";
+
+    // 当插入DATA时，如果类型为NOTE，则更新关联NOTE的内容
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
+            "CREATE TRIGGER update_note_content_on_insert " +
+                    " AFTER INSERT ON " + TABLE.DATA +
+                    " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+                    " BEGIN" +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+                    "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+                    " END";
+
+    // 当更新DATA时，如果类型为NOTE，则更新关联NOTE的内容
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
+            "CREATE TRIGGER update_note_content_on_update " +
+                    " AFTER UPDATE ON " + TABLE.DATA +
+                    " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+                    " BEGIN" +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+                    "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+                    " END";
+
+    // 当删除DATA时，如果类型为NOTE，则更新关联NOTE的内容为空
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
+            "CREATE TRIGGER update_note_content_on_delete " +
+                    " AFTER delete ON " + TABLE.DATA +
+                    " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+                    " BEGIN" +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.SNIPPET + "=''" +
+                    "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
+                    " END";
+
+    // 当删除NOTE时，删除关联的DATA
+    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";
+
+    // 当删除NOTE时，删除属于该NOTE的子NOTE
+    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";
+
+    // 当NOTE移动到回收站文件夹时，将所有子NOTE也移动到回收站
+    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，私有化以防止外部实例化
+     * context 上下文对象，用于访问应用的资源和其他组件
+     */
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+
+    /**
+     * 创建NOTE表，并重新创建NOTE表的触发器，然后创建系统文件夹
+     *db SQLiteDatabase对象，用于执行SQL创建语句
+     */
+    public void createNoteTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
+        Log.d(TAG, "note table has been created");
+    }
+
+    /**
+     * 重新创建笔记表的触发器
+     * db SQLiteDatabase 类型，数据库对象
+     */
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        // 删除旧的触发器
+        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");
+        // 创建新的触发器
+        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
+     * db SQLiteDatabase 类型，数据库对象
+     */
+    private void createSystemFolder(SQLiteDatabase db) {
+        ContentValues values = new ContentValues();
+        // 创建通话记录文件夹
+        values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+        // 创建根文件夹（默认文件夹）
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+        // 创建临时文件夹，用于移动笔记
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+        // 创建回收站文件夹
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+    /**
+     * 创建数据表
+     * db SQLiteDatabase 类型，数据库对象
+     */
+    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");
+    }
+
+    /**
+     * 重新创建数据表的触发器
+     *db SQLiteDatabase 类型，数据库对象
+     */
+    private void reCreateDataTableTriggers(SQLiteDatabase db) {
+        // 删除旧的触发器
+        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");
+        // 创建新的触发器
+        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);
+    }
+
+    /**
+     * 获取 NotesDatabaseHelper 的单例对象
+     *context Context 类型，应用上下文
+     *NotesDatabaseHelper 类型，单例对象
+     */
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    /**
+     * 创建数据库表
+     *
+     * @param db SQLiteDatabase 类型，数据库对象
+     */
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    /**
+     * 升级数据库
+     *
+     * @param db         SQLiteDatabase 类型，数据库对象
+     * @param oldVersion int 类型，旧版本号
+     * @param newVersion int 类型，新版本号
+     */
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
+        // 根据旧版本号逐步升级
+        if (oldVersion == 1) {
+            upgradeToV2(db);
+            skipV2 = true; // 这次升级包括从 v2 到 v3 的升级
+            oldVersion++;
+        }
+        if (oldVersion == 2 && !skipV2) {
+            upgradeToV3(db);
+            reCreateTriggers = true;
+            oldVersion++;
+        }
+        if (oldVersion == 3) {
+            upgradeToV4(db);
+            oldVersion++;
+        }
+        if (reCreateTriggers) {
+            reCreateNoteTableTriggers(db);
+            reCreateDataTableTriggers(db);
+        }
+        if (oldVersion != newVersion) {
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+    /**
+     * 从版本1升级到版本2
+     *
+     * @param db SQLiteDatabase 类型，数据库对象
+     */
+    private void upgradeToV2(SQLiteDatabase db) {
+        // 删除旧表，创建新表
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    /**
+     * 从版本2升级到版本3
+     *
+     * @param db SQLiteDatabase 类型，数据库对象
+     */
+    private void upgradeToV3(SQLiteDatabase db) {
+        // 删除未使用的触发器
+        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");
+        // 添加一个用于 gtask id 的列
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // 添加一个回收站系统文件夹
+        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);
+    }
+
+    /**
+     * 从版本3升级到版本4
+     *
+     * @param db SQLiteDatabase 类型，数据库对象
+     */
+    private void upgradeToV4(SQLiteDatabase db) {
+        // 添加版本号列
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}

src/NotesProvider.java

@@ -0,0 +1,358 @@
+/*
+ * 该类是Notes应用的内容提供者，负责管理Notes的数据，包括查询、插入、更新和删除操作。
+ * 它与数据库交互，将操作转换为对数据库的相应操作。
+ */
+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;
+
+    // 初始化UriMatcher，用于匹配不同的URI请求
+    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);
+    }
+
+    /**
+     * 在搜索结果中，为了显示更多信息，我们会去除标题和内容中的'\n'和空白字符。
+     */
+    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;
+
+    // 用于搜索查询的SQL语句
+    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;
+
+    /**
+     * 当ContentProvider被创建时调用，用于初始化数据库帮助类。
+     *
+     * @return 总是返回true。
+     */
+    @Override
+    public boolean onCreate() {
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+    /**
+     * 根据URI查询数据。
+     *
+     * @param uri           要查询的数据的URI。
+     * @param projection    要返回的列。
+     * @param selection     查询条件。
+     * @param selectionArgs 用于查询条件的参数。
+     * @param sortOrder     排序顺序。
+     * @return 返回匹配的Cursor对象。
+     */
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+                        String sortOrder) {
+        Cursor c = null;
+        SQLiteDatabase db = mHelper.getReadableDatabase();
+        String id = null;
+        // 根据URI匹配查询类型
+        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:
+                // 处理搜索建议的特殊逻辑
+                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);
+        }
+        // 设置通知URI，以便数据改变时可以通知
+        if (c != null) {
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+
+    /**
+     * 在数据库中插入新数据。
+     *
+     * @param uri    插入数据的URI。
+     * @param values 要插入的数据。
+     * @return 返回插入数据的URI。
+     */
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        long dataId = 0, noteId = 0, insertedId = 0;
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+                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);
+        }
+        // 通知URI改变
+        if (noteId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+        return ContentUris.withAppendedId(uri, insertedId);
+    }
+
+    /**
+     * 根据URI删除数据。
+     *
+     * @param uri           要删除数据的URI。
+     * @param selection     删除条件。
+     * @param selectionArgs 用于删除条件的参数。
+     * @return 返回被删除的行数。
+     */
+    @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:
+                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                /**
+                 * ID小于等于0的笔记是系统文件夹，不允许删除
+                 */
+                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);
+        }
+        // 通知URI改变
+        if (count > 0) {
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    /**
+     * 更新数据库中的数据。
+     *
+     * @param uri           要更新数据的URI。
+     * @param values        要更新到的数据。
+     * @param selection     更新条件。
+     * @param selectionArgs 用于更新条件的参数。
+     * @return 返回被更新的行数。
+     */
+    @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:
+                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);
+        }
+
+        // 通知URI改变
+        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，如果存在选择条件，则在条件前后添加" AND (" 和 ')'。
+     *
+     * @param selection 用户提供的选择条件。
+     * @return 如果有选择条件，则返回添加了定界符的选择条件字符串；否则返回空字符串。
+     */
+    private String parseSelection(String selection) {
+        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+    }
+
+    /**
+     * 增加指定笔记的版本号。
+     *
+     * @param id            笔记的ID，如果为正数，则根据ID更新版本号；如果为0或负数，则根据selection参数更新版本号。
+     * @param selection     用于选择需要更新的笔记的条件字符串，可以为空。
+     * @param selectionArgs 与selection参数配合使用的参数数组，用于替换selection中的"?"。
+     */
+    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 ");
+
+        // 根据ID或选择条件构建SQL的WHERE子句
+        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;
+            // 替换selection中的"?"为selectionArgs中的对应参数
+            for (String args : selectionArgs) {
+                selectString = selectString.replaceFirst("\\?", args);
+            }
+            sql.append(selectString);
+        }
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());
+    }
+
+    /**
+     * 根据URI获取对应的MIME类型。
+     * 本方法是个待实现的方法，当前仅返回null。
+     *
+     * @param uri 请求的URI。
+     * @return 返回null，表示该方法尚未实现。
+     */
+    @Override
+    public String getType(Uri uri) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}