diff --git a/README.md b/README.md
index 9ce45f8..0a99726 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # XiaoMiNotes
 
+123
+
diff --git a/doc/小米便签开源代码泛读报告.docx b/doc/小米便签开源代码泛读报告.docx
deleted file mode 100644
index da8741c..0000000
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diff --git a/doc/小米便签泛读报告.docx b/doc/小米便签泛读报告.docx
new file mode 100644
index 0000000..7bb2377
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diff --git a/src/data/Contact.java b/src/data/Contact.java
deleted file mode 100644
index d97ac5d..0000000
--- a/src/data/Contact.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * 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 {
-    private static HashMap<String, String> sContactCache;
-    private static final String TAG = "Contact";
-
-    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 = '+')";
-
-    public static String getContact(Context context, String phoneNumber) {
-        if(sContactCache == null) {
-            sContactCache = new HashMap<String, String>();
-        }
-
-        if(sContactCache.containsKey(phoneNumber)) {
-            return sContactCache.get(phoneNumber);
-        }
-
-        String selection = CALLER_ID_SELECTION.replace("+",
-                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
-        Cursor cursor = context.getContentResolver().query(
-                Data.CONTENT_URI,
-                new String [] { Phone.DISPLAY_NAME },
-                selection,
-                new String[] { phoneNumber },
-                null);
-
-        if (cursor != null && cursor.moveToFirst()) {
-            try {
-                String name = cursor.getString(0);
-                sContactCache.put(phoneNumber, name);
-                return name;
-            } catch (IndexOutOfBoundsException e) {
-                Log.e(TAG, " Cursor get string error " + e.toString());
-                return null;
-            } finally {
-                cursor.close();
-            }
-        } else {
-            Log.d(TAG, "No contact matched with number:" + phoneNumber);
-            return null;
-        }
-    }
-}
diff --git a/src/data/NotesDatabaseHelper.java b/src/data/NotesDatabaseHelper.java
deleted file mode 100644
index ffe5d57..0000000
--- a/src/data/NotesDatabaseHelper.java
+++ /dev/null
@@ -1,362 +0,0 @@
-/*
- * 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");
-    }
-}
diff --git a/src/gtask/data/MetaData.java b/src/gtask/data/MetaData.java
deleted file mode 100644
index 3a2050b..0000000
--- a/src/gtask/data/MetaData.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * 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;
-
-
-public class MetaData extends Task {
-    private final static String TAG = MetaData.class.getSimpleName();
-
-    private String mRelatedGid = null;
-
-    public void setMeta(String gid, JSONObject metaInfo) {
-        try {
-            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
-        } catch (JSONException e) {
-            Log.e(TAG, "failed to put related gid");
-        }
-        setNotes(metaInfo.toString());
-        setName(GTaskStringUtils.META_NOTE_NAME);
-    }
-
-    public String getRelatedGid() {
-        return mRelatedGid;
-    }
-
-    @Override
-    public boolean isWorthSaving() {
-        return getNotes() != null;
-    }
-
-    @Override
-    public void setContentByRemoteJSON(JSONObject js) {
-        super.setContentByRemoteJSON(js);
-        if (getNotes() != null) {
-            try {
-                JSONObject metaInfo = new JSONObject(getNotes().trim());
-                mRelatedGid = metaInfo.getString(GTaskStringUtils.META_HEAD_GTASK_ID);
-            } catch (JSONException e) {
-                Log.w(TAG, "failed to get related gid");
-                mRelatedGid = null;
-            }
-        }
-    }
-
-    @Override
-    public void setContentByLocalJSON(JSONObject js) {
-        // this function should not be called
-        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
-    }
-
-    @Override
-    public JSONObject getLocalJSONFromContent() {
-        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
-    }
-
-    @Override
-    public int getSyncAction(Cursor c) {
-        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
-    }
-
-}
diff --git a/src/gtask/data/Node.java b/src/gtask/data/Node.java
deleted file mode 100644
index 63950e0..0000000
--- a/src/gtask/data/Node.java
+++ /dev/null
@@ -1,101 +0,0 @@
-/*
- * 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;
-
-public abstract class Node {
-    public static final int SYNC_ACTION_NONE = 0;
-
-    public static final int SYNC_ACTION_ADD_REMOTE = 1;
-
-    public static final int SYNC_ACTION_ADD_LOCAL = 2;
-
-    public static final int SYNC_ACTION_DEL_REMOTE = 3;
-
-    public static final int SYNC_ACTION_DEL_LOCAL = 4;
-
-    public static final int SYNC_ACTION_UPDATE_REMOTE = 5;
-
-    public static final int SYNC_ACTION_UPDATE_LOCAL = 6;
-
-    public static final int SYNC_ACTION_UPDATE_CONFLICT = 7;
-
-    public static final int SYNC_ACTION_ERROR = 8;
-
-    private String mGid;
-
-    private String mName;
-
-    private long mLastModified;
-
-    private boolean mDeleted;
-
-    public Node() {
-        mGid = null;
-        mName = "";
-        mLastModified = 0;
-        mDeleted = false;
-    }
-
-    public abstract JSONObject getCreateAction(int actionId);
-
-    public abstract JSONObject getUpdateAction(int actionId);
-
-    public abstract void setContentByRemoteJSON(JSONObject js);
-
-    public abstract void setContentByLocalJSON(JSONObject js);
-
-    public abstract JSONObject getLocalJSONFromContent();
-
-    public abstract int getSyncAction(Cursor c);
-
-    public void setGid(String gid) {
-        this.mGid = gid;
-    }
-
-    public void setName(String name) {
-        this.mName = name;
-    }
-
-    public void setLastModified(long lastModified) {
-        this.mLastModified = lastModified;
-    }
-
-    public void setDeleted(boolean deleted) {
-        this.mDeleted = deleted;
-    }
-
-    public String getGid() {
-        return this.mGid;
-    }
-
-    public String getName() {
-        return this.mName;
-    }
-
-    public long getLastModified() {
-        return this.mLastModified;
-    }
-
-    public boolean getDeleted() {
-        return this.mDeleted;
-    }
-
-}
diff --git a/src/gtask/data/SqlNote.java b/src/gtask/data/SqlNote.java
deleted file mode 100644
index 79a4095..0000000
--- a/src/gtask/data/SqlNote.java
+++ /dev/null
@@ -1,505 +0,0 @@
-/*
- * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *        http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package net.micode.notes.gtask.data;
-
-import android.appwidget.AppWidgetManager;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.database.Cursor;
-import android.net.Uri;
-import android.util.Log;
-
-import net.micode.notes.data.Notes;
-import net.micode.notes.data.Notes.DataColumns;
-import net.micode.notes.data.Notes.NoteColumns;
-import net.micode.notes.gtask.exception.ActionFailureException;
-import net.micode.notes.tool.GTaskStringUtils;
-import net.micode.notes.tool.ResourceParser;
-
-import org.json.JSONArray;
-import org.json.JSONException;
-import org.json.JSONObject;
-
-import java.util.ArrayList;
-
-
-public class SqlNote {
-    private static final String TAG = SqlNote.class.getSimpleName();
-
-    private static final int INVALID_ID = -99999;
-
-    public static final String[] PROJECTION_NOTE = new String[] {
-            NoteColumns.ID, NoteColumns.ALERTED_DATE, NoteColumns.BG_COLOR_ID,
-            NoteColumns.CREATED_DATE, NoteColumns.HAS_ATTACHMENT, NoteColumns.MODIFIED_DATE,
-            NoteColumns.NOTES_COUNT, NoteColumns.PARENT_ID, NoteColumns.SNIPPET, NoteColumns.TYPE,
-            NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE, NoteColumns.SYNC_ID,
-            NoteColumns.LOCAL_MODIFIED, NoteColumns.ORIGIN_PARENT_ID, NoteColumns.GTASK_ID,
-            NoteColumns.VERSION
-    };
-
-    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;
-
-    private ContentResolver mContentResolver;
-
-    private boolean mIsCreate;
-
-    private long mId;
-
-    private long mAlertDate;
-
-    private int mBgColorId;
-
-    private long mCreatedDate;
-
-    private int mHasAttachment;
-
-    private long mModifiedDate;
-
-    private long mParentId;
-
-    private String mSnippet;
-
-    private int mType;
-
-    private int mWidgetId;
-
-    private int mWidgetType;
-
-    private long mOriginParent;
-
-    private long mVersion;
-
-    private ContentValues mDiffNoteValues;
-
-    private ArrayList<SqlData> mDataList;
-
-    public SqlNote(Context context) {
-        mContext = context;
-        mContentResolver = context.getContentResolver();
-        mIsCreate = true;
-        mId = INVALID_ID;
-        mAlertDate = 0;
-        mBgColorId = ResourceParser.getDefaultBgId(context);
-        mCreatedDate = System.currentTimeMillis();
-        mHasAttachment = 0;
-        mModifiedDate = System.currentTimeMillis();
-        mParentId = 0;
-        mSnippet = "";
-        mType = Notes.TYPE_NOTE;
-        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
-        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
-        mOriginParent = 0;
-        mVersion = 0;
-        mDiffNoteValues = new ContentValues();
-        mDataList = new ArrayList<SqlData>();
-    }
-
-    public SqlNote(Context context, Cursor c) {
-        mContext = context;
-        mContentResolver = context.getContentResolver();
-        mIsCreate = false;
-        loadFromCursor(c);
-        mDataList = new ArrayList<SqlData>();
-        if (mType == Notes.TYPE_NOTE)
-            loadDataContent();
-        mDiffNoteValues = new ContentValues();
-    }
-
-    public SqlNote(Context context, long id) {
-        mContext = context;
-        mContentResolver = context.getContentResolver();
-        mIsCreate = false;
-        loadFromCursor(id);
-        mDataList = new ArrayList<SqlData>();
-        if (mType == Notes.TYPE_NOTE)
-            loadDataContent();
-        mDiffNoteValues = new ContentValues();
-
-    }
-
-    private void loadFromCursor(long id) {
-        Cursor c = null;
-        try {
-            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
-                    new String[] {
-                        String.valueOf(id)
-                    }, null);
-            if (c != null) {
-                c.moveToNext();
-                loadFromCursor(c);
-            } else {
-                Log.w(TAG, "loadFromCursor: cursor = null");
-            }
-        } finally {
-            if (c != null)
-                c.close();
-        }
-    }
-
-    private void loadFromCursor(Cursor c) {
-        mId = c.getLong(ID_COLUMN);
-        mAlertDate = c.getLong(ALERTED_DATE_COLUMN);
-        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN);
-        mCreatedDate = c.getLong(CREATED_DATE_COLUMN);
-        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN);
-        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN);
-        mParentId = c.getLong(PARENT_ID_COLUMN);
-        mSnippet = c.getString(SNIPPET_COLUMN);
-        mType = c.getInt(TYPE_COLUMN);
-        mWidgetId = c.getInt(WIDGET_ID_COLUMN);
-        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN);
-        mVersion = c.getLong(VERSION_COLUMN);
-    }
-
-    private void loadDataContent() {
-        Cursor c = null;
-        mDataList.clear();
-        try {
-            c = mContentResolver.query(Notes.CONTENT_DATA_URI, SqlData.PROJECTION_DATA,
-                    "(note_id=?)", new String[] {
-                        String.valueOf(mId)
-                    }, null);
-            if (c != null) {
-                if (c.getCount() == 0) {
-                    Log.w(TAG, "it seems that the note has not data");
-                    return;
-                }
-                while (c.moveToNext()) {
-                    SqlData data = new SqlData(mContext, c);
-                    mDataList.add(data);
-                }
-            } else {
-                Log.w(TAG, "loadDataContent: cursor = null");
-            }
-        } finally {
-            if (c != null)
-                c.close();
-        }
-    }
-
-    public boolean setContent(JSONObject js) {
-        try {
-            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
-            if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
-                Log.w(TAG, "cannot set system folder");
-            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
-                // for folder we can only update the snnipet and type
-                String snippet = note.has(NoteColumns.SNIPPET) ? note
-                        .getString(NoteColumns.SNIPPET) : "";
-                if (mIsCreate || !mSnippet.equals(snippet)) {
-                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
-                }
-                mSnippet = snippet;
-
-                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
-                        : Notes.TYPE_NOTE;
-                if (mIsCreate || mType != type) {
-                    mDiffNoteValues.put(NoteColumns.TYPE, type);
-                }
-                mType = type;
-            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_NOTE) {
-                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
-                long id = note.has(NoteColumns.ID) ? note.getLong(NoteColumns.ID) : INVALID_ID;
-                if (mIsCreate || mId != id) {
-                    mDiffNoteValues.put(NoteColumns.ID, id);
-                }
-                mId = id;
-
-                long alertDate = note.has(NoteColumns.ALERTED_DATE) ? note
-                        .getLong(NoteColumns.ALERTED_DATE) : 0;
-                if (mIsCreate || mAlertDate != alertDate) {
-                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate);
-                }
-                mAlertDate = alertDate;
-
-                int bgColorId = note.has(NoteColumns.BG_COLOR_ID) ? note
-                        .getInt(NoteColumns.BG_COLOR_ID) : ResourceParser.getDefaultBgId(mContext);
-                if (mIsCreate || mBgColorId != bgColorId) {
-                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId);
-                }
-                mBgColorId = bgColorId;
-
-                long createDate = note.has(NoteColumns.CREATED_DATE) ? note
-                        .getLong(NoteColumns.CREATED_DATE) : System.currentTimeMillis();
-                if (mIsCreate || mCreatedDate != createDate) {
-                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate);
-                }
-                mCreatedDate = createDate;
-
-                int hasAttachment = note.has(NoteColumns.HAS_ATTACHMENT) ? note
-                        .getInt(NoteColumns.HAS_ATTACHMENT) : 0;
-                if (mIsCreate || mHasAttachment != hasAttachment) {
-                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment);
-                }
-                mHasAttachment = hasAttachment;
-
-                long modifiedDate = note.has(NoteColumns.MODIFIED_DATE) ? note
-                        .getLong(NoteColumns.MODIFIED_DATE) : System.currentTimeMillis();
-                if (mIsCreate || mModifiedDate != modifiedDate) {
-                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate);
-                }
-                mModifiedDate = modifiedDate;
-
-                long parentId = note.has(NoteColumns.PARENT_ID) ? note
-                        .getLong(NoteColumns.PARENT_ID) : 0;
-                if (mIsCreate || mParentId != parentId) {
-                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId);
-                }
-                mParentId = parentId;
-
-                String snippet = note.has(NoteColumns.SNIPPET) ? note
-                        .getString(NoteColumns.SNIPPET) : "";
-                if (mIsCreate || !mSnippet.equals(snippet)) {
-                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
-                }
-                mSnippet = snippet;
-
-                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
-                        : Notes.TYPE_NOTE;
-                if (mIsCreate || mType != type) {
-                    mDiffNoteValues.put(NoteColumns.TYPE, type);
-                }
-                mType = type;
-
-                int widgetId = note.has(NoteColumns.WIDGET_ID) ? note.getInt(NoteColumns.WIDGET_ID)
-                        : AppWidgetManager.INVALID_APPWIDGET_ID;
-                if (mIsCreate || mWidgetId != widgetId) {
-                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId);
-                }
-                mWidgetId = widgetId;
-
-                int widgetType = note.has(NoteColumns.WIDGET_TYPE) ? note
-                        .getInt(NoteColumns.WIDGET_TYPE) : Notes.TYPE_WIDGET_INVALIDE;
-                if (mIsCreate || mWidgetType != widgetType) {
-                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType);
-                }
-                mWidgetType = widgetType;
-
-                long originParent = note.has(NoteColumns.ORIGIN_PARENT_ID) ? note
-                        .getLong(NoteColumns.ORIGIN_PARENT_ID) : 0;
-                if (mIsCreate || mOriginParent != originParent) {
-                    mDiffNoteValues.put(NoteColumns.ORIGIN_PARENT_ID, originParent);
-                }
-                mOriginParent = originParent;
-
-                for (int i = 0; i < dataArray.length(); i++) {
-                    JSONObject data = dataArray.getJSONObject(i);
-                    SqlData sqlData = null;
-                    if (data.has(DataColumns.ID)) {
-                        long dataId = data.getLong(DataColumns.ID);
-                        for (SqlData temp : mDataList) {
-                            if (dataId == temp.getId()) {
-                                sqlData = temp;
-                            }
-                        }
-                    }
-
-                    if (sqlData == null) {
-                        sqlData = new SqlData(mContext);
-                        mDataList.add(sqlData);
-                    }
-
-                    sqlData.setContent(data);
-                }
-            }
-        } catch (JSONException e) {
-            Log.e(TAG, e.toString());
-            e.printStackTrace();
-            return false;
-        }
-        return true;
-    }
-
-    public JSONObject getContent() {
-        try {
-            JSONObject js = new JSONObject();
-
-            if (mIsCreate) {
-                Log.e(TAG, "it seems that we haven't created this in database yet");
-                return null;
-            }
-
-            JSONObject note = new JSONObject();
-            if (mType == Notes.TYPE_NOTE) {
-                note.put(NoteColumns.ID, mId);
-                note.put(NoteColumns.ALERTED_DATE, mAlertDate);
-                note.put(NoteColumns.BG_COLOR_ID, mBgColorId);
-                note.put(NoteColumns.CREATED_DATE, mCreatedDate);
-                note.put(NoteColumns.HAS_ATTACHMENT, mHasAttachment);
-                note.put(NoteColumns.MODIFIED_DATE, mModifiedDate);
-                note.put(NoteColumns.PARENT_ID, mParentId);
-                note.put(NoteColumns.SNIPPET, mSnippet);
-                note.put(NoteColumns.TYPE, mType);
-                note.put(NoteColumns.WIDGET_ID, mWidgetId);
-                note.put(NoteColumns.WIDGET_TYPE, mWidgetType);
-                note.put(NoteColumns.ORIGIN_PARENT_ID, mOriginParent);
-                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
-
-                JSONArray dataArray = new JSONArray();
-                for (SqlData sqlData : mDataList) {
-                    JSONObject data = sqlData.getContent();
-                    if (data != null) {
-                        dataArray.put(data);
-                    }
-                }
-                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
-            } else if (mType == Notes.TYPE_FOLDER || mType == Notes.TYPE_SYSTEM) {
-                note.put(NoteColumns.ID, mId);
-                note.put(NoteColumns.TYPE, mType);
-                note.put(NoteColumns.SNIPPET, mSnippet);
-                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
-            }
-
-            return js;
-        } catch (JSONException e) {
-            Log.e(TAG, e.toString());
-            e.printStackTrace();
-        }
-        return null;
-    }
-
-    public void setParentId(long id) {
-        mParentId = id;
-        mDiffNoteValues.put(NoteColumns.PARENT_ID, id);
-    }
-
-    public void setGtaskId(String gid) {
-        mDiffNoteValues.put(NoteColumns.GTASK_ID, gid);
-    }
-
-    public void setSyncId(long syncId) {
-        mDiffNoteValues.put(NoteColumns.SYNC_ID, syncId);
-    }
-
-    public void resetLocalModified() {
-        mDiffNoteValues.put(NoteColumns.LOCAL_MODIFIED, 0);
-    }
-
-    public long getId() {
-        return mId;
-    }
-
-    public long getParentId() {
-        return mParentId;
-    }
-
-    public String getSnippet() {
-        return mSnippet;
-    }
-
-    public boolean isNoteType() {
-        return mType == Notes.TYPE_NOTE;
-    }
-
-    public void commit(boolean validateVersion) {
-        if (mIsCreate) {
-            if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
-                mDiffNoteValues.remove(NoteColumns.ID);
-            }
-
-            Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues);
-            try {
-                mId = Long.valueOf(uri.getPathSegments().get(1));
-            } catch (NumberFormatException e) {
-                Log.e(TAG, "Get note id error :" + e.toString());
-                throw new ActionFailureException("create note failed");
-            }
-            if (mId == 0) {
-                throw new IllegalStateException("Create thread id failed");
-            }
-
-            if (mType == Notes.TYPE_NOTE) {
-                for (SqlData sqlData : mDataList) {
-                    sqlData.commit(mId, false, -1);
-                }
-            }
-        } else {
-            if (mId <= 0 && mId != Notes.ID_ROOT_FOLDER && mId != Notes.ID_CALL_RECORD_FOLDER) {
-                Log.e(TAG, "No such note");
-                throw new IllegalStateException("Try to update note with invalid id");
-            }
-            if (mDiffNoteValues.size() > 0) {
-                mVersion ++;
-                int result = 0;
-                if (!validateVersion) {
-                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
-                            + NoteColumns.ID + "=?)", new String[] {
-                        String.valueOf(mId)
-                    });
-                } else {
-                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
-                            + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
-                            new String[] {
-                                    String.valueOf(mId), String.valueOf(mVersion)
-                            });
-                }
-                if (result == 0) {
-                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
-                }
-            }
-
-            if (mType == Notes.TYPE_NOTE) {
-                for (SqlData sqlData : mDataList) {
-                    sqlData.commit(mId, validateVersion, mVersion);
-                }
-            }
-        }
-
-        // refresh local info
-        loadFromCursor(mId);
-        if (mType == Notes.TYPE_NOTE)
-            loadDataContent();
-
-        mDiffNoteValues.clear();
-        mIsCreate = false;
-    }
-}
diff --git a/src/net/micode/notes/data/Contact.java b/src/net/micode/notes/data/Contact.java
new file mode 100644
index 0000000..df62799
--- /dev/null
+++ b/src/net/micode/notes/data/Contact.java
@@ -0,0 +1,114 @@
+/*
+ * 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;  // 属于小米便签的数据层包，专门处理数据相关操作
+
+import android.content.Context;  // Android上下文，用于访问应用资源
+import android.database.Cursor;  // 数据库查询结果集，用于遍历查询结果
+import android.provider.ContactsContract.CommonDataKinds.Phone;  // 通讯录电话号码相关常量
+import android.provider.ContactsContract.Data;  // 通讯录数据相关常量
+import android.telephony.PhoneNumberUtils;  // 电话号码工具类，用于格式化比较号码
+import android.util.Log;  // Android日志工具
+
+import java.util.HashMap;  // HashMap集合，用于缓存联系人信息
+
+/**
+ * Contact 类 - 联系人工具类
+ * 功能：根据电话号码查询通讯录获取联系人姓名
+ * 设计模式：使用单例模式和缓存机制优化性能
+ * 技术特点：
+ * 1. 使用Android ContentProvider访问系统通讯录
+ * 2. 实现LRU缓存机制避免重复查询
+ * 3. 使用电话号码模糊匹配算法
+ */
+public class Contact {
+    // 静态联系人缓存：使用HashMap存储<电话号码, 联系人姓名>键值对
+    // 使用静态变量实现应用级别的缓存，减少对通讯录的频繁访问
+    private static HashMap<String, String> sContactCache;
+
+    // 日志标签，用于调试和问题追踪
+    private static final String TAG = "Contact";
+
+    // 查询条件语句模板：用于构建查询通讯录的SQL WHERE条件
+    // 注意：这里使用"+"作为占位符，后面会被替换为最小匹配位数
+    // PHONE_NUMBERS_EQUAL()是Android提供的特殊函数，用于电话号码匹配
+    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
+            + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
+            + " AND " + Data.RAW_CONTACT_ID + " IN "
+            + "(SELECT raw_contact_id "
+            + " FROM phone_lookup"  // phone_lookup是Android系统的电话号码查询优化表
+            + " WHERE min_match = '+')";  // "+"是占位符，会被替换为实际的最小匹配位数
+
+    /**
+     * 根据电话号码获取联系人姓名
+     * @param context Android上下文，用于访问ContentResolver
+     * @param phoneNumber 要查询的电话号码
+     * @return 联系人姓名，如果未找到则返回null
+     * 方法逻辑：
+     * 1. 首先检查缓存中是否已有该号码对应的联系人
+     * 2. 如果缓存未命中，查询系统通讯录
+     * 3. 将查询结果存入缓存
+     * 4. 返回查询结果
+     */
+    public static String getContact(Context context, String phoneNumber) {
+        // 延迟初始化缓存：第一次使用时才创建HashMap
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+
+        // 检查缓存：如果缓存中已有该号码，直接返回缓存的联系人姓名
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+
+        // 构建查询条件：替换占位符"+"为电话号码的最小匹配位数
+        // PhoneNumberUtils.toCallerIDMinMatch()计算电话号码的最小匹配位数
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+
+        // 通过ContentResolver查询系统通讯录
+        // Data.CONTENT_URI：通讯录数据的统一资源标识符
+        // 查询条件：电话号码匹配且数据类型为电话号码
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,  // 通讯录数据URI
+                new String [] { Phone.DISPLAY_NAME },  // 只查询显示名字段
+                selection,  // 查询条件
+                new String[] { phoneNumber },  // 查询参数：电话号码
+                null);  // 排序条件：不排序
+
+        // 处理查询结果
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                // 获取第一条结果的联系人姓名
+                String name = cursor.getString(0);
+                // 将结果存入缓存
+                sContactCache.put(phoneNumber, name);
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+                // 捕获数组越界异常，记录错误日志
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                // 无论是否成功，都必须关闭Cursor释放资源
+                cursor.close();
+            }
+        } else {
+            // 没有找到匹配的联系人，记录调试日志
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/data/Notes.java b/src/net/micode/notes/data/Notes.java
similarity index 54%
rename from src/data/Notes.java
rename to src/net/micode/notes/data/Notes.java
index f240604..24c05c0 100644
--- a/src/data/Notes.java
+++ b/src/net/micode/notes/data/Notes.java
@@ -17,24 +17,28 @@
 package net.micode.notes.data;
 
 import android.net.Uri;
+
+/**
+ * Notes 类 - 便签应用的核心常量定义类
+ * 包含数据库表定义、ContentProvider URI、Intent键、便签类型等常量
+ * 采用接口定义列名和嵌套类分层设计
+ */
 public class Notes {
     public static final String AUTHORITY = "micode_notes";
     public static final String TAG = "Notes";
+
+    // 便签类型
     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
-     */
+    // 系统文件夹ID
     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;
 
+    // Intent Extra键
     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";
@@ -42,238 +46,83 @@ public class Notes {
     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";
 
+    // 小部件类型
     public static final int TYPE_WIDGET_INVALIDE      = -1;
     public static final int TYPE_WIDGET_2X            = 0;
     public static final int TYPE_WIDGET_4X            = 1;
 
+    /**
+     * DataConstants - 数据类型常量
+     */
     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");
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
 
     /**
-     * Uri to query data
+     * NoteColumns - 便签表列定义
      */
-    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";
     }
 
+    /**
+     * DataColumns - 便签数据表列定义，采用EAV模型
+     */
     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";
     }
 
+    /**
+     * TextNote - 文本便签的特定列定义
+     */
     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 String MODE = DATA1;  // 1:清单模式 0:普通模式
         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");
     }
 
+    /**
+     * CallNote - 通话记录便签的特定列定义
+     */
     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 CALL_DATE = DATA1;   // 通话日期
+        public static final String PHONE_NUMBER = DATA3; // 电话号码
 
         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");
     }
-}
+}
\ No newline at end of file
diff --git a/src/net/micode/notes/data/NotesDatabaseHelper.java b/src/net/micode/notes/data/NotesDatabaseHelper.java
new file mode 100644
index 0000000..826bdf2
--- /dev/null
+++ b/src/net/micode/notes/data/NotesDatabaseHelper.java
@@ -0,0 +1,403 @@
+/*
+ * 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;
+
+/**
+ * NotesDatabaseHelper 类 - 便签数据库辅助类
+ *
+ * 功能：管理便签应用的SQLite数据库创建和版本升级
+ * 继承自SQLiteOpenHelper，实现数据库的创建、升级和初始化
+ * 包含note表和data表，以及相关的触发器定义
+ */
+public class NotesDatabaseHelper extends SQLiteOpenHelper {
+    // 数据库名称
+    private static final String DB_NAME = "note.db";
+    // 数据库版本号，用于数据库升级管理
+    private static final int DB_VERSION = 4;
+
+    // 表名常量接口
+    public interface TABLE {
+        public static final String NOTE = "note"; // 便签主表
+        public static final String DATA = "data"; // 便签数据表
+    }
+
+    private static final String TAG = "NotesDatabaseHelper"; // 日志标签
+
+    private static NotesDatabaseHelper mInstance; // 单例实例
+
+    // 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 + ");";
+
+    // 触发器：当更新便签的父文件夹时，增加目标文件夹的便签计数
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+            "CREATE TRIGGER increase_folder_count_on_update "+
+                    " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+                    " BEGIN " +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+                    "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+                    " END";
+
+    // 触发器：当更新便签的父文件夹时，减少原文件夹的便签计数
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+            "CREATE TRIGGER decrease_folder_count_on_update " +
+                    " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+                    " BEGIN " +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+                    "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+                    "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
+                    " END";
+
+    // 触发器：当插入新便签时，增加父文件夹的便签计数
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
+            "CREATE TRIGGER increase_folder_count_on_insert " +
+                    " AFTER INSERT ON " + TABLE.NOTE +
+                    " BEGIN " +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+                    "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+                    " END";
+
+    // 触发器：当删除便签时，减少父文件夹的便签计数
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
+            "CREATE TRIGGER decrease_folder_count_on_delete " +
+                    " AFTER DELETE ON " + TABLE.NOTE +
+                    " BEGIN " +
+                    "  UPDATE " + TABLE.NOTE +
+                    "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+                    "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+                    "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
+                    " END";
+
+    // 触发器：当插入数据且类型为普通便签时，更新便签的snippet字段
+    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";
+
+    // 触发器：当更新数据且类型为普通便签时，更新便签的snippet字段
+    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";
+
+    // 触发器：当删除数据且类型为普通便签时，清空便签的snippet字段
+    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";
+
+    // 触发器：当删除便签时，同步删除该便签的所有数据
+    private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
+            "CREATE TRIGGER delete_data_on_delete " +
+                    " AFTER DELETE ON " + TABLE.NOTE +
+                    " BEGIN" +
+                    "  DELETE FROM " + TABLE.DATA +
+                    "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
+                    " END";
+
+    // 触发器：当删除文件夹时，同步删除该文件夹下的所有便签（级联删除）
+    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";
+
+    // 触发器：当文件夹被移动到回收站时，将该文件夹下的所有便签也移动到回收站
+    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";
+
+    /**
+     * 构造方法
+     * @param context Android上下文
+     */
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+
+    /**
+     * 创建note表及其触发器和系统文件夹
+     * @param db SQLiteDatabase对象
+     */
+    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note表的所有触发器（先删除后创建）
+     * @param db SQLiteDatabase对象
+     */
+    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（通话记录文件夹、根文件夹、临时文件夹、回收站文件夹）
+     * @param db SQLiteDatabase对象
+     */
+    private void createSystemFolder(SQLiteDatabase db) {
+        ContentValues values = new ContentValues();
+
+        // 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);
+
+        // 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);
+
+        // 临时文件夹（用于移动便签时的暂存）
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        // 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data表及其触发器和索引
+     * @param db SQLiteDatabase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data表的所有触发器（先删除后创建）
+     * @param db SQLiteDatabase对象
+     */
+    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);
+    }
+
+    /**
+     * 获取单例实例（线程安全）
+     * @param context Android上下文
+     * @return NotesDatabaseHelper单例实例
+     */
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    /**
+     * 数据库首次创建时调用，创建所有表和触发器
+     * @param db SQLiteDatabase对象
+     */
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    /**
+     * 数据库升级时调用，根据旧版本号逐步升级
+     * @param db SQLiteDatabase对象
+     * @param oldVersion 旧版本号
+     * @param newVersion 新版本号
+     */
+    @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; // 此次升级已包含从v2到v3的升级
+            oldVersion++;
+        }
+
+        // 从版本2升级到版本3（如果未跳过）
+        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);
+        }
+
+        // 如果版本号不匹配，抛出异常
+        if (oldVersion != newVersion) {
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+    /**
+     * 升级到版本2：删除旧表并重新创建
+     * @param db SQLiteDatabase对象
+     */
+    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);
+    }
+
+    /**
+     * 升级到版本3：
+     * 1. 删除不再使用的触发器
+     * 2. 添加gtask_id列
+     * 3. 添加回收站系统文件夹
+     * @param db SQLiteDatabase对象
+     */
+    private void upgradeToV3(SQLiteDatabase db) {
+        // 删除不再使用的触发器
+        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gtask_id列
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // 添加回收站系统文件夹
+        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);
+    }
+
+    /**
+     * 升级到版本4：添加version列
+     * @param db SQLiteDatabase对象
+     */
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}
\ No newline at end of file
diff --git a/src/data/NotesProvider.java b/src/net/micode/notes/data/NotesProvider.java
similarity index 62%
rename from src/data/NotesProvider.java
rename to src/net/micode/notes/data/NotesProvider.java
index edb0a60..6e71154 100644
--- a/src/data/NotesProvider.java
+++ b/src/net/micode/notes/data/NotesProvider.java
@@ -16,7 +16,6 @@
 
 package net.micode.notes.data;
 
-
 import android.app.SearchManager;
 import android.content.ContentProvider;
 import android.content.ContentUris;
@@ -34,22 +33,28 @@ import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
-
+/**
+ * NotesProvider 类 - 便签应用的ContentProvider
+ *
+ * 功能：为便签应用提供数据访问接口，通过ContentProvider机制实现数据共享
+ * 继承自ContentProvider，实现对note表和data表的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 UriMatcher mMatcher; // URI匹配器，用于匹配不同的URI请求
 
-    private static final String TAG = "NotesProvider";
+    private NotesDatabaseHelper mHelper; // 数据库帮助类实例
 
-    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 String TAG = "NotesProvider"; // 日志标签
 
-    private static final int URI_SEARCH          = 5;
-    private static final int URI_SEARCH_SUGGEST  = 6;
+    // URI匹配常量定义
+    private static final int URI_NOTE            = 1; // 匹配note表所有记录
+    private static final int URI_NOTE_ITEM       = 2; // 匹配note表单条记录
+    private static final int URI_DATA            = 3; // 匹配data表所有记录
+    private static final int URI_DATA_ITEM       = 4; // 匹配data表单条记录
+    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
 
+    // 静态初始化块：初始化URI匹配器，添加各种URI模式
     static {
         mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
         mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
@@ -62,76 +67,92 @@ public class NotesProvider extends ContentProvider {
     }
 
     /**
-     * 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.
+     * 搜索投影字段定义：
+     * x'0A' 表示SQLite中的换行符'\n'
+     * 对于搜索结果中的标题和内容，我们将修剪'\n'和空格以显示更多信息
      */
     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;
+            + 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;
 
+    // 便签片段搜索查询语句
     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;
+            + " FROM " + TABLE.NOTE
+            + " WHERE " + NoteColumns.SNIPPET + " LIKE ?" // 模糊匹配搜索条件
+            + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER // 排除回收站中的便签
+            + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE; // 只搜索普通便签类型
 
+    /**
+     * ContentProvider创建时调用，初始化数据库帮助类
+     * @return true表示初始化成功
+     */
     @Override
     public boolean onCreate() {
         mHelper = NotesDatabaseHelper.getInstance(getContext());
         return true;
     }
 
+    /**
+     * 查询方法，根据URI匹配不同的查询逻辑
+     * @param uri 请求的URI
+     * @param projection 要返回的列
+     * @param selection 查询条件
+     * @param selectionArgs 查询参数
+     * @param sortOrder 排序方式
+     * @return 查询结果的Cursor对象
+     */
     @Override
     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
-            String sortOrder) {
+                        String sortOrder) {
         Cursor c = null;
         SQLiteDatabase db = mHelper.getReadableDatabase();
         String id = null;
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
+            case URI_NOTE: // 查询note表所有记录
                 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
                         sortOrder);
                 break;
-            case URI_NOTE_ITEM:
-                id = uri.getPathSegments().get(1);
+            case URI_NOTE_ITEM: // 查询note表单条记录
+                id = uri.getPathSegments().get(1); // 从URI路径段中获取ID
                 c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs, null, null, sortOrder);
                 break;
-            case URI_DATA:
+            case URI_DATA: // 查询data表所有记录
                 c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
                         sortOrder);
                 break;
-            case URI_DATA_ITEM:
+            case URI_DATA_ITEM: // 查询data表单条记录
                 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:
+            case URI_SEARCH_SUGGEST: // 处理搜索和搜索建议请求
                 if (sortOrder != null || projection != null) {
                     throw new IllegalArgumentException(
                             "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
                 }
 
                 String searchString = null;
+                // 根据URI类型获取搜索字符串
                 if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
                     if (uri.getPathSegments().size() > 1) {
                         searchString = uri.getPathSegments().get(1);
                     }
                 } else {
-                    searchString = uri.getQueryParameter("pattern");
+                    searchString = uri.getQueryParameter("pattern"); // 从查询参数获取搜索模式
                 }
 
                 if (TextUtils.isEmpty(searchString)) {
-                    return null;
+                    return null; // 搜索字符串为空则返回null
                 }
 
                 try {
-                    searchString = String.format("%%%s%%", searchString);
+                    searchString = String.format("%%%s%%", searchString); // 添加通配符进行模糊匹配
                     c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
                             new String[] { searchString });
                 } catch (IllegalStateException ex) {
@@ -141,21 +162,28 @@ public class NotesProvider extends ContentProvider {
             default:
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
+        // 设置通知URI，以便在数据变化时能够通知观察者
         if (c != null) {
             c.setNotificationUri(getContext().getContentResolver(), uri);
         }
         return c;
     }
 
+    /**
+     * 插入数据方法
+     * @param uri 请求的URI
+     * @param values 要插入的数据
+     * @return 插入数据的新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:
+            case URI_NOTE: // 插入note表记录
                 insertedId = noteId = db.insert(TABLE.NOTE, null, values);
                 break;
-            case URI_DATA:
+            case URI_DATA: // 插入data表记录
                 if (values.containsKey(DataColumns.NOTE_ID)) {
                     noteId = values.getAsLong(DataColumns.NOTE_ID);
                 } else {
@@ -166,50 +194,57 @@ public class NotesProvider extends ContentProvider {
             default:
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
-        // Notify the note uri
+        // 通知note URI的数据变化
         if (noteId > 0) {
             getContext().getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
         }
 
-        // Notify the data uri
+        // 通知data URI的数据变化
         if (dataId > 0) {
             getContext().getContentResolver().notifyChange(
                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
         }
 
+        // 返回新插入数据的URI
         return ContentUris.withAppendedId(uri, insertedId);
     }
 
+    /**
+     * 删除数据方法
+     * @param uri 请求的URI
+     * @param selection 删除条件
+     * @param selectionArgs 删除参数
+     * @return 删除的记录数
+     */
     @Override
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
-        boolean deleteData = false;
+        boolean deleteData = false; // 标记是否删除data表数据
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
+            case URI_NOTE: // 删除note表记录（系统文件夹不允许删除）
                 selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
                 count = db.delete(TABLE.NOTE, selection, selectionArgs);
                 break;
-            case URI_NOTE_ITEM:
+            case URI_NOTE_ITEM: // 删除note表单条记录
                 id = uri.getPathSegments().get(1);
                 /**
-                 * ID that smaller than 0 is system folder which is not allowed to
-                 * trash
+                 * ID小于0的是系统文件夹，不允许删除
                  */
                 long noteId = Long.valueOf(id);
                 if (noteId <= 0) {
-                    break;
+                    break; // 系统文件夹不删除
                 }
                 count = db.delete(TABLE.NOTE,
                         NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
                 break;
-            case URI_DATA:
+            case URI_DATA: // 删除data表记录
                 count = db.delete(TABLE.DATA, selection, selectionArgs);
                 deleteData = true;
                 break;
-            case URI_DATA_ITEM:
+            case URI_DATA_ITEM: // 删除data表单条记录
                 id = uri.getPathSegments().get(1);
                 count = db.delete(TABLE.DATA,
                         DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
@@ -218,8 +253,10 @@ public class NotesProvider extends ContentProvider {
             default:
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
+        // 如果删除了记录，通知数据变化
         if (count > 0) {
             if (deleteData) {
+                // 删除data表数据时需要通知note URI
                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
             }
             getContext().getContentResolver().notifyChange(uri, null);
@@ -227,28 +264,36 @@ public class NotesProvider extends ContentProvider {
         return count;
     }
 
+    /**
+     * 更新数据方法
+     * @param uri 请求的URI
+     * @param values 更新的数据
+     * @param selection 更新条件
+     * @param selectionArgs 更新参数
+     * @return 更新的记录数
+     */
     @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;
+        boolean updateData = false; // 标记是否更新data表数据
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
-                increaseNoteVersion(-1, selection, selectionArgs);
+            case URI_NOTE: // 更新note表记录
+                increaseNoteVersion(-1, selection, selectionArgs); // 增加版本号
                 count = db.update(TABLE.NOTE, values, selection, selectionArgs);
                 break;
-            case URI_NOTE_ITEM:
+            case URI_NOTE_ITEM: // 更新note表单条记录
                 id = uri.getPathSegments().get(1);
-                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs); // 增加版本号
                 count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs);
                 break;
-            case URI_DATA:
+            case URI_DATA: // 更新data表记录
                 count = db.update(TABLE.DATA, values, selection, selectionArgs);
                 updateData = true;
                 break;
-            case URI_DATA_ITEM:
+            case URI_DATA_ITEM: // 更新data表单条记录
                 id = uri.getPathSegments().get(1);
                 count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs);
@@ -258,8 +303,10 @@ public class NotesProvider extends ContentProvider {
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
 
+        // 如果更新了记录，通知数据变化
         if (count > 0) {
             if (updateData) {
+                // 更新data表数据时需要通知note URI
                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
             }
             getContext().getContentResolver().notifyChange(uri, null);
@@ -267,18 +314,30 @@ public class NotesProvider extends ContentProvider {
         return count;
     }
 
+    /**
+     * 解析选择条件，将传入的条件转换为AND连接的条件
+     * @param selection 原始选择条件
+     * @return 解析后的选择条件字符串
+     */
     private String parseSelection(String selection) {
         return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
     }
 
+    /**
+     * 增加便签版本号
+     * @param id 便签ID（大于0）或-1表示更新所有匹配的记录
+     * @param selection 更新条件
+     * @param selectionArgs 更新参数
+     */
     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 ");
+        sql.append("=" + NoteColumns.VERSION + "+1 "); // 版本号加1
 
+        // 构建WHERE子句
         if (id > 0 || !TextUtils.isEmpty(selection)) {
             sql.append(" WHERE ");
         }
@@ -287,19 +346,25 @@ public class NotesProvider extends ContentProvider {
         }
         if (!TextUtils.isEmpty(selection)) {
             String selectString = id > 0 ? parseSelection(selection) : selection;
+            // 替换参数占位符
             for (String args : selectionArgs) {
                 selectString = selectString.replaceFirst("\\?", args);
             }
             sql.append(selectString);
         }
 
+        // 执行SQL语句
         mHelper.getWritableDatabase().execSQL(sql.toString());
     }
 
+    /**
+     * 获取URI对应的MIME类型（暂未实现）
+     * @param uri 请求的URI
+     * @return MIME类型字符串
+     */
     @Override
     public String getType(Uri uri) {
         // TODO Auto-generated method stub
         return null;
     }
-
-}
+}
\ No newline at end of file
diff --git a/src/net/micode/notes/gtask/data/MetaData.java b/src/net/micode/notes/gtask/data/MetaData.java
new file mode 100644
index 0000000..e30d451
--- /dev/null
+++ b/src/net/micode/notes/gtask/data/MetaData.java
@@ -0,0 +1,124 @@
+/*
+ * 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;
+
+/**
+ * MetaData 类 - 元数据实体类
+ *
+ * 功能：用于存储和管理与Google Tasks同步相关的元数据信息
+ * 继承自Task类，专门处理便签与Google Tasks的关联关系
+ * 设计为不可直接调用的辅助类，主要存储关联的Google Task ID
+ */
+public class MetaData extends Task {
+    private final static String TAG = MetaData.class.getSimpleName(); // 日志标签
+
+    private String mRelatedGid = null; // 关联的Google Task ID
+
+    /**
+     * 设置元数据
+     * @param gid Google Task的ID
+     * @param metaInfo 包含元信息的JSONObject对象
+     */
+    public void setMeta(String gid, JSONObject metaInfo) {
+        try {
+            // 将Google Task ID添加到元信息中
+            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
+        } catch (JSONException e) {
+            Log.e(TAG, "failed to put related gid"); // 记录错误日志
+        }
+        setNotes(metaInfo.toString()); // 将JSON字符串设置为便签内容
+        setName(GTaskStringUtils.META_NOTE_NAME); // 设置元数据便签的名称
+    }
+
+    /**
+     * 获取关联的Google Task ID
+     * @return 关联的Google Task ID，如果不存在则返回null
+     */
+    public String getRelatedGid() {
+        return mRelatedGid;
+    }
+
+    /**
+     * 判断是否值得保存（是否有有效的便签内容）
+     * @return 如果有便签内容则返回true，否则返回false
+     */
+    @Override
+    public boolean isWorthSaving() {
+        return getNotes() != null;
+    }
+
+    /**
+     * 从远程JSON数据设置内容（从Google Tasks服务器获取）
+     * @param js 包含远程数据的JSONObject对象
+     */
+    @Override
+    public void setContentByRemoteJSON(JSONObject js) {
+        super.setContentByRemoteJSON(js); // 调用父类方法设置基础内容
+        if (getNotes() != null) {
+            try {
+                // 解析便签内容为JSON，提取关联的Google Task ID
+                JSONObject metaInfo = new JSONObject(getNotes().trim());
+                mRelatedGid = metaInfo.getString(GTaskStringUtils.META_HEAD_GTASK_ID);
+            } catch (JSONException e) {
+                Log.w(TAG, "failed to get related gid"); // 记录警告日志
+                mRelatedGid = null; // 解析失败时设为null
+            }
+        }
+    }
+
+    /**
+     * 从本地JSON数据设置内容（禁止调用）
+     * @param js 本地JSON数据
+     * @throws IllegalAccessError 始终抛出此异常，表示此方法不应被调用
+     */
+    @Override
+    public void setContentByLocalJSON(JSONObject js) {
+        // 此方法不应被调用，MetaData不从本地JSON设置内容
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+    }
+
+    /**
+     * 从内容获取本地JSON数据（禁止调用）
+     * @return 本地JSON数据
+     * @throws IllegalAccessError 始终抛出此异常，表示此方法不应被调用
+     */
+    @Override
+    public JSONObject getLocalJSONFromContent() {
+        // 此方法不应被调用，MetaData不生成本地JSON
+        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
+    }
+
+    /**
+     * 获取同步操作（禁止调用）
+     * @param c 数据库游标
+     * @return 同步操作类型
+     * @throws IllegalAccessError 始终抛出此异常，表示此方法不应被调用
+     */
+    @Override
+    public int getSyncAction(Cursor c) {
+        // 此方法不应被调用，MetaData不处理同步操作
+        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
+    }
+}
\ No newline at end of file
diff --git a/src/net/micode/notes/gtask/data/Node.java b/src/net/micode/notes/gtask/data/Node.java
new file mode 100644
index 0000000..344be2e
--- /dev/null
+++ b/src/net/micode/notes/gtask/data/Node.java
@@ -0,0 +1,165 @@
+/*
+ * 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;
+
+/**
+ * Node 类 - 数据节点的抽象基类
+ *
+ * 功能：定义与Google Tasks同步的数据节点的通用属性和行为
+ * 这是一个抽象类，为便签同步提供基础框架，包含同步操作状态码和基本数据字段
+ * 采用模板方法模式，具体的数据节点（如Task、MetaData等）需要实现抽象方法
+ */
+public abstract class Node {
+    // 同步操作状态码定义
+    public static final int SYNC_ACTION_NONE = 0;           // 无需同步
+    public static final int SYNC_ACTION_ADD_REMOTE = 1;     // 添加数据到远程
+    public static final int SYNC_ACTION_ADD_LOCAL = 2;      // 添加数据到本地
+    public static final int SYNC_ACTION_DEL_REMOTE = 3;     // 删除远程数据
+    public static final int SYNC_ACTION_DEL_LOCAL = 4;      // 删除本地数据
+    public static final int SYNC_ACTION_UPDATE_REMOTE = 5;  // 更新远程数据
+    public static final int SYNC_ACTION_UPDATE_LOCAL = 6;   // 更新本地数据
+    public static final int SYNC_ACTION_UPDATE_CONFLICT = 7;// 更新冲突
+    public static final int SYNC_ACTION_ERROR = 8;          // 同步错误
+
+    // 节点属性字段
+    private String mGid;          // Google Task ID（全局唯一标识）
+    private String mName;         // 节点名称
+    private long mLastModified;   // 最后修改时间戳
+    private boolean mDeleted;     // 删除标记
+
+    /**
+     * 默认构造函数，初始化节点属性
+     */
+    public Node() {
+        mGid = null;
+        mName = "";
+        mLastModified = 0;
+        mDeleted = false;
+    }
+
+    // =============== 抽象方法定义 ===============
+    // 这些方法需要子类根据具体的数据类型来实现
+
+    /**
+     * 获取创建操作的JSON数据
+     * @param actionId 操作ID
+     * @return 包含创建操作数据的JSONObject
+     */
+    public abstract JSONObject getCreateAction(int actionId);
+
+    /**
+     * 获取更新操作的JSON数据
+     * @param actionId 操作ID
+     * @return 包含更新操作数据的JSONObject
+     */
+    public abstract JSONObject getUpdateAction(int actionId);
+
+    /**
+     * 从远程JSON数据设置节点内容（从Google Tasks服务器获取）
+     * @param js 包含远程数据的JSONObject
+     */
+    public abstract void setContentByRemoteJSON(JSONObject js);
+
+    /**
+     * 从本地JSON数据设置节点内容（从本地数据库获取）
+     * @param js 包含本地数据的JSONObject
+     */
+    public abstract void setContentByLocalJSON(JSONObject js);
+
+    /**
+     * 从节点内容生成本地JSON数据（用于本地存储）
+     * @return 包含本地数据的JSONObject
+     */
+    public abstract JSONObject getLocalJSONFromContent();
+
+    /**
+     * 根据数据库游标确定同步操作类型
+     * @param c 数据库查询结果的Cursor
+     * @return 同步操作状态码（SYNC_ACTION_*）
+     */
+    public abstract int getSyncAction(Cursor c);
+
+    // =============== Getter和Setter方法 ===============
+
+    /**
+     * 设置Google Task ID
+     * @param gid Google Task的全局唯一标识
+     */
+    public void setGid(String gid) {
+        this.mGid = gid;
+    }
+
+    /**
+     * 设置节点名称
+     * @param name 节点名称
+     */
+    public void setName(String name) {
+        this.mName = name;
+    }
+
+    /**
+     * 设置最后修改时间戳
+     * @param lastModified 最后修改时间戳（毫秒）
+     */
+    public void setLastModified(long lastModified) {
+        this.mLastModified = lastModified;
+    }
+
+    /**
+     * 设置删除标记
+     * @param deleted true表示节点已删除，false表示节点有效
+     */
+    public void setDeleted(boolean deleted) {
+        this.mDeleted = deleted;
+    }
+
+    /**
+     * 获取Google Task ID
+     * @return Google Task的全局唯一标识
+     */
+    public String getGid() {
+        return this.mGid;
+    }
+
+    /**
+     * 获取节点名称
+     * @return 节点名称
+     */
+    public String getName() {
+        return this.mName;
+    }
+
+    /**
+     * 获取最后修改时间戳
+     * @return 最后修改时间戳（毫秒）
+     */
+    public long getLastModified() {
+        return this.mLastModified;
+    }
+
+    /**
+     * 获取删除标记
+     * @return true表示节点已删除，false表示节点有效
+     */
+    public boolean getDeleted() {
+        return this.mDeleted;
+    }
+}
\ No newline at end of file
diff --git a/src/gtask/data/SqlData.java b/src/net/micode/notes/gtask/data/SqlData.java
similarity index 59%
rename from src/gtask/data/SqlData.java
rename to src/net/micode/notes/gtask/data/SqlData.java
index d3ec3be..77a98c4 100644
--- a/src/gtask/data/SqlData.java
+++ b/src/net/micode/notes/gtask/data/SqlData.java
@@ -34,61 +34,71 @@ import net.micode.notes.gtask.exception.ActionFailureException;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-
+/**
+ * SqlData 类 - 数据库数据操作类
+ *
+ * 功能：封装对便签数据表（data表）的CRUD操作，提供JSON数据与数据库记录的转换
+ * 用于在本地数据库和Google Tasks同步之间进行数据映射和转换
+ * 实现数据的差异更新和版本控制，提高同步效率
+ */
 public class SqlData {
-    private static final String TAG = SqlData.class.getSimpleName();
+    private static final String TAG = SqlData.class.getSimpleName(); // 日志标签
 
-    private static final int INVALID_ID = -99999;
+    private static final int INVALID_ID = -99999; // 无效ID标识
 
+    // 数据表查询字段投影
     public static final String[] PROJECTION_DATA = new String[] {
             DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1,
             DataColumns.DATA3
     };
 
-    public static final int DATA_ID_COLUMN = 0;
-
-    public static final int DATA_MIME_TYPE_COLUMN = 1;
-
-    public static final int DATA_CONTENT_COLUMN = 2;
-
-    public static final int DATA_CONTENT_DATA_1_COLUMN = 3;
-
-    public static final int DATA_CONTENT_DATA_3_COLUMN = 4;
-
-    private ContentResolver mContentResolver;
-
-    private boolean mIsCreate;
-
-    private long mDataId;
-
-    private String mDataMimeType;
-
-    private String mDataContent;
-
-    private long mDataContentData1;
-
-    private String mDataContentData3;
-
-    private ContentValues mDiffDataValues;
-
+    // 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，用于访问ContentProvider
+    private boolean mIsCreate;                // 创建标记：true表示新数据，false表示已存在数据
+    private long mDataId;                     // 数据ID
+    private String mDataMimeType;             // 数据MIME类型
+    private String mDataContent;              // 数据内容
+    private long mDataContentData1;           // 数据DATA1字段值
+    private String mDataContentData3;         // 数据DATA3字段值
+    private ContentValues mDiffDataValues;    // 差异数据值，用于记录需要更新的字段
+
+    /**
+     * 构造函数：创建新的SqlData对象（用于创建新数据）
+     * @param context Android上下文
+     */
     public SqlData(Context context) {
         mContentResolver = context.getContentResolver();
-        mIsCreate = true;
-        mDataId = INVALID_ID;
-        mDataMimeType = DataConstants.NOTE;
-        mDataContent = "";
-        mDataContentData1 = 0;
-        mDataContentData3 = "";
-        mDiffDataValues = new ContentValues();
+        mIsCreate = true; // 标记为新数据
+        mDataId = INVALID_ID; // 初始化ID为无效值
+        mDataMimeType = DataConstants.NOTE; // 默认MIME类型为普通便签
+        mDataContent = ""; // 初始化内容为空
+        mDataContentData1 = 0; // 初始化DATA1为0
+        mDataContentData3 = ""; // 初始化DATA3为空
+        mDiffDataValues = new ContentValues(); // 创建差异值容器
     }
 
+    /**
+     * 构造函数：从数据库游标创建SqlData对象（用于加载已有数据）
+     * @param context Android上下文
+     * @param c 数据库查询结果的Cursor
+     */
     public SqlData(Context context, Cursor c) {
         mContentResolver = context.getContentResolver();
-        mIsCreate = false;
-        loadFromCursor(c);
-        mDiffDataValues = new ContentValues();
+        mIsCreate = false; // 标记为已有数据
+        loadFromCursor(c); // 从游标加载数据
+        mDiffDataValues = new ContentValues(); // 创建差异值容器
     }
 
+    /**
+     * 从数据库游标加载数据到内存字段
+     * @param c 数据库查询结果的Cursor
+     */
     private void loadFromCursor(Cursor c) {
         mDataId = c.getLong(DATA_ID_COLUMN);
         mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN);
@@ -97,13 +107,20 @@ public class SqlData {
         mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN);
     }
 
+    /**
+     * 从JSON对象设置数据内容，并记录变更的字段
+     * @param js 包含数据的JSONObject
+     * @throws JSONException JSON解析异常
+     */
     public void setContent(JSONObject js) throws JSONException {
+        // 处理数据ID
         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
         String dataMimeType = js.has(DataColumns.MIME_TYPE) ? js.getString(DataColumns.MIME_TYPE)
                 : DataConstants.NOTE;
         if (mIsCreate || !mDataMimeType.equals(dataMimeType)) {
@@ -111,18 +128,21 @@ public class SqlData {
         }
         mDataMimeType = dataMimeType;
 
+        // 处理内容
         String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : "";
         if (mIsCreate || !mDataContent.equals(dataContent)) {
             mDiffDataValues.put(DataColumns.CONTENT, dataContent);
         }
         mDataContent = dataContent;
 
+        // 处理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);
@@ -130,11 +150,17 @@ public class SqlData {
         mDataContentData3 = dataContentData3;
     }
 
+    /**
+     * 获取当前数据的JSON表示
+     * @return 包含数据的JSONObject，如果是新数据则返回null
+     * @throws JSONException JSON创建异常
+     */
     public JSONObject getContent() throws JSONException {
         if (mIsCreate) {
             Log.e(TAG, "it seems that we haven't created this in database yet");
             return null;
         }
+        // 创建JSON对象并添加所有字段
         JSONObject js = new JSONObject();
         js.put(DataColumns.ID, mDataId);
         js.put(DataColumns.MIME_TYPE, mDataMimeType);
@@ -144,30 +170,41 @@ public class SqlData {
         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（仅在validateVersion为true时使用）
+     * @throws ActionFailureException 数据提交失败异常
+     */
     public void commit(long noteId, boolean validateVersion, long version) {
-
         if (mIsCreate) {
+            // 创建新数据记录
             if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) {
                 mDiffDataValues.remove(DataColumns.ID);
             }
 
-            mDiffDataValues.put(DataColumns.NOTE_ID, noteId);
+            mDiffDataValues.put(DataColumns.NOTE_ID, noteId); // 设置关联的便签ID
             Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues);
             try {
+                // 从返回的URI中提取新创建的数据ID
                 mDataId = Long.valueOf(uri.getPathSegments().get(1));
             } catch (NumberFormatException e) {
                 Log.e(TAG, "Get note id error :" + e.toString());
                 throw new ActionFailureException("create note failed");
             }
         } else {
+            // 更新已有数据记录
             if (mDiffDataValues.size() > 0) {
                 int result = 0;
                 if (!validateVersion) {
+                    // 不验证版本号，直接更新
                     result = mContentResolver.update(ContentUris.withAppendedId(
                             Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null);
                 } else {
+                    // 验证版本号，确保数据未被其他操作修改
                     result = mContentResolver.update(ContentUris.withAppendedId(
-                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues,
+                                    Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues,
                             " ? in (SELECT " + NoteColumns.ID + " FROM " + TABLE.NOTE
                                     + " WHERE " + NoteColumns.VERSION + "=?)", new String[] {
                                     String.valueOf(noteId), String.valueOf(version)
@@ -179,11 +216,16 @@ public class SqlData {
             }
         }
 
+        // 重置状态
         mDiffDataValues.clear();
         mIsCreate = false;
     }
 
+    /**
+     * 获取数据ID
+     * @return 数据ID
+     */
     public long getId() {
         return mDataId;
     }
-}
+}
\ No newline at end of file
diff --git a/src/net/micode/notes/gtask/data/SqlNote.java b/src/net/micode/notes/gtask/data/SqlNote.java
new file mode 100644
index 0000000..137f89c
--- /dev/null
+++ b/src/net/micode/notes/gtask/data/SqlNote.java
@@ -0,0 +1,572 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+import net.micode.notes.tool.ResourceParser;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+
+/**
+ * 数据库笔记类（用于与Google Task同步）
+ * 负责在SQLite数据库和JSON格式之间转换笔记数据
+ */
+public class SqlNote {
+    private static final String TAG = SqlNote.class.getSimpleName(); // 日志标签
+
+    private static final int INVALID_ID = -99999; // 无效ID常量
+
+    // 数据库查询的投影字段（需要查询的列）
+    public static final String[] PROJECTION_NOTE = new String[] {
+            NoteColumns.ID, NoteColumns.ALERTED_DATE, NoteColumns.BG_COLOR_ID,
+            NoteColumns.CREATED_DATE, NoteColumns.HAS_ATTACHMENT, NoteColumns.MODIFIED_DATE,
+            NoteColumns.NOTES_COUNT, NoteColumns.PARENT_ID, NoteColumns.SNIPPET, NoteColumns.TYPE,
+            NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE, NoteColumns.SYNC_ID,
+            NoteColumns.LOCAL_MODIFIED, NoteColumns.ORIGIN_PARENT_ID, NoteColumns.GTASK_ID,
+            NoteColumns.VERSION
+    };
+
+    // 投影字段对应的索引号
+    public static final int ID_COLUMN = 0; // ID列索引
+    public static final int ALERTED_DATE_COLUMN = 1; // 提醒日期列索引
+    public static final int BG_COLOR_ID_COLUMN = 2; // 背景颜色ID列索引
+    public static final int CREATED_DATE_COLUMN = 3; // 创建日期列索引
+    public static final int HAS_ATTACHMENT_COLUMN = 4; // 是否有附件列索引
+    public static final int MODIFIED_DATE_COLUMN = 5; // 修改日期列索引
+    public static final int NOTES_COUNT_COLUMN = 6; // 笔记数量列索引
+    public static final int PARENT_ID_COLUMN = 7; // 父ID列索引
+    public static final int SNIPPET_COLUMN = 8; // 摘要内容列索引
+    public static final int TYPE_COLUMN = 9; // 类型列索引
+    public static final int WIDGET_ID_COLUMN = 10; // 小部件ID列索引
+    public static final int WIDGET_TYPE_COLUMN = 11; // 小部件类型列索引
+    public static final int SYNC_ID_COLUMN = 12; // 同步ID列索引
+    public static final int LOCAL_MODIFIED_COLUMN = 13; // 本地修改标记列索引
+    public static final int ORIGIN_PARENT_ID_COLUMN = 14; // 原始父ID列索引
+    public static final int GTASK_ID_COLUMN = 15; // Google Task ID列索引
+    public static final int VERSION_COLUMN = 16; // 版本号列索引
+
+    private Context mContext; // 上下文对象
+    private ContentResolver mContentResolver; // 内容解析器，用于数据库操作
+    private boolean mIsCreate; // 标记是否为新建笔记（true表示新建，false表示从数据库加载）
+    private long mId; // 笔记ID
+    private long mAlertDate; // 提醒日期
+    private int mBgColorId; // 背景颜色ID
+    private long mCreatedDate; // 创建日期
+    private int mHasAttachment; // 是否有附件（0表示无，1表示有）
+    private long mModifiedDate; // 修改日期
+    private long mParentId; // 父文件夹ID
+    private String mSnippet; // 笔记内容摘要
+    private int mType; // 笔记类型（笔记、文件夹、系统文件夹等）
+    private int mWidgetId; // 关联的小部件ID
+    private int mWidgetType; // 小部件类型
+    private long mOriginParent; // 原始父文件夹ID（用于恢复操作）
+    private long mVersion; // 版本号（用于乐观锁控制）
+    private ContentValues mDiffNoteValues; // 存储需要更新的字段值（用于数据库更新）
+    private ArrayList<SqlData> mDataList; // 笔记内容数据列表（用于普通笔记类型）
+
+    /**
+     * 构造函数 - 创建新笔记对象
+     * 初始化所有字段为默认值，标记为创建状态
+     * @param context 上下文
+     */
+    public SqlNote(Context context) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true; // 标记为新建笔记
+        mId = INVALID_ID; // 使用无效ID
+        mAlertDate = 0; // 默认无提醒
+        mBgColorId = ResourceParser.getDefaultBgId(context); // 获取默认背景颜色ID
+        mCreatedDate = System.currentTimeMillis(); // 使用当前时间作为创建时间
+        mHasAttachment = 0; // 默认无附件
+        mModifiedDate = System.currentTimeMillis(); // 使用当前时间作为修改时间
+        mParentId = 0; // 默认父ID为0
+        mSnippet = ""; // 空摘要
+        mType = Notes.TYPE_NOTE; // 默认为普通笔记类型
+        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID; // 无效的小部件ID
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE; // 无效的小部件类型
+        mOriginParent = 0; // 默认原始父ID为0
+        mVersion = 0; // 初始版本为0
+        mDiffNoteValues = new ContentValues(); // 初始化更新字段容器
+        mDataList = new ArrayList<SqlData>(); // 初始化数据列表
+    }
+
+    /**
+     * 构造函数 - 从数据库游标加载笔记对象
+     * 从数据库查询结果中加载笔记数据，并加载关联的笔记内容
+     * @param context 上下文
+     * @param c 数据库游标，包含笔记数据
+     */
+    public SqlNote(Context context, Cursor c) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false; // 标记为从数据库加载
+        loadFromCursor(c); // 从游标加载数据
+        mDataList = new ArrayList<SqlData>(); // 初始化数据列表
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent(); // 如果是普通笔记类型，加载笔记内容数据
+        mDiffNoteValues = new ContentValues(); // 初始化更新字段容器
+    }
+
+    /**
+     * 构造函数 - 通过笔记ID加载笔记对象
+     * 根据笔记ID查询数据库并加载笔记数据
+     * @param context 上下文
+     * @param id 笔记ID
+     */
+    public SqlNote(Context context, long id) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false; // 标记为从数据库加载
+        loadFromCursor(id); // 通过ID从数据库加载数据
+        mDataList = new ArrayList<SqlData>(); // 初始化数据列表
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent(); // 如果是普通笔记类型，加载笔记内容数据
+        mDiffNoteValues = new ContentValues(); // 初始化更新字段容器
+    }
+
+    /**
+     * 通过笔记ID从数据库加载笔记数据
+     * 根据ID查询数据库并将结果加载到对象字段中
+     * @param id 笔记ID
+     */
+    private void loadFromCursor(long id) {
+        Cursor c = null;
+        try {
+            // 查询指定ID的笔记
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
+                    new String[] {
+                            String.valueOf(id)
+                    }, null);
+            if (c != null) {
+                c.moveToNext(); // 移动到查询结果的第一行
+                loadFromCursor(c); // 从游标加载数据
+            } else {
+                Log.w(TAG, "loadFromCursor: cursor = null"); // 日志记录游标为空
+            }
+        } finally {
+            if (c != null)
+                c.close(); // 关闭游标
+        }
+    }
+
+    /**
+     * 从游标加载数据到对象字段
+     * 将数据库游标中的数据赋值给对象的各个字段
+     * @param c 数据库游标
+     */
+    private void loadFromCursor(Cursor c) {
+        mId = c.getLong(ID_COLUMN); // 获取笔记ID
+        mAlertDate = c.getLong(ALERTED_DATE_COLUMN); // 获取提醒日期
+        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN); // 获取背景颜色ID
+        mCreatedDate = c.getLong(CREATED_DATE_COLUMN); // 获取创建日期
+        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN); // 获取是否有附件
+        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN); // 获取修改日期
+        mParentId = c.getLong(PARENT_ID_COLUMN); // 获取父文件夹ID
+        mSnippet = c.getString(SNIPPET_COLUMN); // 获取笔记摘要
+        mType = c.getInt(TYPE_COLUMN); // 获取笔记类型
+        mWidgetId = c.getInt(WIDGET_ID_COLUMN); // 获取小部件ID
+        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN); // 获取小部件类型
+        mVersion = c.getLong(VERSION_COLUMN); // 获取版本号
+    }
+
+    /**
+     * 加载笔记的内容数据
+     * 查询笔记关联的内容数据（如文本内容）并加载到数据列表
+     */
+    private void loadDataContent() {
+        Cursor c = null;
+        mDataList.clear(); // 清空数据列表
+        try {
+            // 查询笔记的内容数据
+            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"); // 日志记录笔记无内容数据
+                    return;
+                }
+                while (c.moveToNext()) {
+                    SqlData data = new SqlData(mContext, c); // 创建SqlData对象
+                    mDataList.add(data); // 添加到数据列表
+                }
+            } else {
+                Log.w(TAG, "loadDataContent: cursor = null"); // 日志记录游标为空
+            }
+        } finally {
+            if (c != null)
+                c.close(); // 关闭游标
+        }
+    }
+
+    /**
+     * 从JSON对象设置笔记内容
+     * 解析JSON数据并更新笔记对象的各个字段
+     * @param js 包含笔记数据的JSON对象
+     * @return 设置成功返回true，失败返回false
+     */
+    public boolean setContent(JSONObject js) {
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE); // 获取笔记JSON对象
+            if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                Log.w(TAG, "cannot set system folder"); // 系统文件夹不能设置
+            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                // 对于文件夹类型，只能更新摘要和类型
+                String snippet = note.has(NoteColumns.SNIPPET) ? note
+                        .getString(NoteColumns.SNIPPET) : ""; // 获取摘要，如果不存在则为空字符串
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet); // 如果摘要发生变化，记录更新
+                }
+                mSnippet = snippet; // 更新摘要字段
+
+                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE; // 获取类型，如果不存在则默认为笔记类型
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type); // 如果类型发生变化，记录更新
+                }
+                mType = type; // 更新类型字段
+            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_NOTE) {
+                // 对于普通笔记类型，需要设置所有字段
+                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA); // 获取笔记内容数据数组
+                long id = note.has(NoteColumns.ID) ? note.getLong(NoteColumns.ID) : INVALID_ID; // 获取笔记ID
+                if (mIsCreate || mId != id) {
+                    mDiffNoteValues.put(NoteColumns.ID, id); // 如果ID发生变化，记录更新
+                }
+                mId = id; // 更新ID字段
+
+                long alertDate = note.has(NoteColumns.ALERTED_DATE) ? note
+                        .getLong(NoteColumns.ALERTED_DATE) : 0; // 获取提醒日期
+                if (mIsCreate || mAlertDate != alertDate) {
+                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate); // 如果提醒日期变化，记录更新
+                }
+                mAlertDate = alertDate; // 更新提醒日期字段
+
+                int bgColorId = note.has(NoteColumns.BG_COLOR_ID) ? note
+                        .getInt(NoteColumns.BG_COLOR_ID) : ResourceParser.getDefaultBgId(mContext); // 获取背景颜色ID
+                if (mIsCreate || mBgColorId != bgColorId) {
+                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId); // 如果背景颜色变化，记录更新
+                }
+                mBgColorId = bgColorId; // 更新背景颜色ID字段
+
+                long createDate = note.has(NoteColumns.CREATED_DATE) ? note
+                        .getLong(NoteColumns.CREATED_DATE) : System.currentTimeMillis(); // 获取创建日期
+                if (mIsCreate || mCreatedDate != createDate) {
+                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate); // 如果创建日期变化，记录更新
+                }
+                mCreatedDate = createDate; // 更新创建日期字段
+
+                int hasAttachment = note.has(NoteColumns.HAS_ATTACHMENT) ? note
+                        .getInt(NoteColumns.HAS_ATTACHMENT) : 0; // 获取是否有附件
+                if (mIsCreate || mHasAttachment != hasAttachment) {
+                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment); // 如果附件状态变化，记录更新
+                }
+                mHasAttachment = hasAttachment; // 更新附件字段
+
+                long modifiedDate = note.has(NoteColumns.MODIFIED_DATE) ? note
+                        .getLong(NoteColumns.MODIFIED_DATE) : System.currentTimeMillis(); // 获取修改日期
+                if (mIsCreate || mModifiedDate != modifiedDate) {
+                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate); // 如果修改日期变化，记录更新
+                }
+                mModifiedDate = modifiedDate; // 更新修改日期字段
+
+                long parentId = note.has(NoteColumns.PARENT_ID) ? note
+                        .getLong(NoteColumns.PARENT_ID) : 0; // 获取父文件夹ID
+                if (mIsCreate || mParentId != parentId) {
+                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId); // 如果父ID变化，记录更新
+                }
+                mParentId = parentId; // 更新父ID字段
+
+                String snippet = note.has(NoteColumns.SNIPPET) ? note
+                        .getString(NoteColumns.SNIPPET) : ""; // 获取摘要
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet); // 如果摘要变化，记录更新
+                }
+                mSnippet = snippet; // 更新摘要字段
+
+                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE; // 获取笔记类型
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type); // 如果类型变化，记录更新
+                }
+                mType = type; // 更新类型字段
+
+                int widgetId = note.has(NoteColumns.WIDGET_ID) ? note.getInt(NoteColumns.WIDGET_ID)
+                        : AppWidgetManager.INVALID_APPWIDGET_ID; // 获取小部件ID
+                if (mIsCreate || mWidgetId != widgetId) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId); // 如果小部件ID变化，记录更新
+                }
+                mWidgetId = widgetId; // 更新小部件ID字段
+
+                int widgetType = note.has(NoteColumns.WIDGET_TYPE) ? note
+                        .getInt(NoteColumns.WIDGET_TYPE) : Notes.TYPE_WIDGET_INVALIDE; // 获取小部件类型
+                if (mIsCreate || mWidgetType != widgetType) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType); // 如果小部件类型变化，记录更新
+                }
+                mWidgetType = widgetType; // 更新小部件类型字段
+
+                long originParent = note.has(NoteColumns.ORIGIN_PARENT_ID) ? note
+                        .getLong(NoteColumns.ORIGIN_PARENT_ID) : 0; // 获取原始父文件夹ID
+                if (mIsCreate || mOriginParent != originParent) {
+                    mDiffNoteValues.put(NoteColumns.ORIGIN_PARENT_ID, originParent); // 如果原始父ID变化，记录更新
+                }
+                mOriginParent = originParent; // 更新原始父ID字段
+
+                // 处理笔记内容数据
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i); // 获取每条内容数据
+                    SqlData sqlData = null;
+                    if (data.has(DataColumns.ID)) {
+                        long dataId = data.getLong(DataColumns.ID); // 获取内容数据ID
+                        // 在现有数据列表中查找匹配的内容数据
+                        for (SqlData temp : mDataList) {
+                            if (dataId == temp.getId()) {
+                                sqlData = temp; // 找到已存在的数据
+                            }
+                        }
+                    }
+
+                    if (sqlData == null) {
+                        sqlData = new SqlData(mContext); // 创建新的内容数据对象
+                        mDataList.add(sqlData); // 添加到数据列表
+                    }
+
+                    sqlData.setContent(data); // 设置内容数据
+                }
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString()); // 记录JSON解析异常
+            e.printStackTrace();
+            return false; // 返回失败
+        }
+        return true; // 返回成功
+    }
+
+    /**
+     * 获取笔记的JSON表示
+     * 将笔记对象转换为JSON格式，用于同步或传输
+     * @return 包含笔记数据的JSON对象，失败返回null
+     */
+    public JSONObject getContent() {
+        try {
+            JSONObject js = new JSONObject(); // 创建JSON对象
+
+            if (mIsCreate) {
+                Log.e(TAG, "it seems that we haven't created this in database yet"); // 日志记录笔记尚未创建
+                return null; // 返回null
+            }
+
+            JSONObject note = new JSONObject(); // 创建笔记JSON对象
+            if (mType == Notes.TYPE_NOTE) {
+                // 普通笔记类型，包含所有字段
+                note.put(NoteColumns.ID, mId); // 添加ID
+                note.put(NoteColumns.ALERTED_DATE, mAlertDate); // 添加提醒日期
+                note.put(NoteColumns.BG_COLOR_ID, mBgColorId); // 添加背景颜色ID
+                note.put(NoteColumns.CREATED_DATE, mCreatedDate); // 添加创建日期
+                note.put(NoteColumns.HAS_ATTACHMENT, mHasAttachment); // 添加附件状态
+                note.put(NoteColumns.MODIFIED_DATE, mModifiedDate); // 添加修改日期
+                note.put(NoteColumns.PARENT_ID, mParentId); // 添加父文件夹ID
+                note.put(NoteColumns.SNIPPET, mSnippet); // 添加摘要
+                note.put(NoteColumns.TYPE, mType); // 添加类型
+                note.put(NoteColumns.WIDGET_ID, mWidgetId); // 添加小部件ID
+                note.put(NoteColumns.WIDGET_TYPE, mWidgetType); // 添加小部件类型
+                note.put(NoteColumns.ORIGIN_PARENT_ID, mOriginParent); // 添加原始父文件夹ID
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note); // 将笔记对象添加到JSON
+
+                // 添加笔记内容数据
+                JSONArray dataArray = new JSONArray(); // 创建内容数据数组
+                for (SqlData sqlData : mDataList) {
+                    JSONObject data = sqlData.getContent(); // 获取内容数据的JSON
+                    if (data != null) {
+                        dataArray.put(data); // 添加到数组
+                    }
+                }
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray); // 将内容数据数组添加到JSON
+            } else if (mType == Notes.TYPE_FOLDER || mType == Notes.TYPE_SYSTEM) {
+                // 文件夹或系统文件夹类型，只包含必要字段
+                note.put(NoteColumns.ID, mId); // 添加ID
+                note.put(NoteColumns.TYPE, mType); // 添加类型
+                note.put(NoteColumns.SNIPPET, mSnippet); // 添加摘要
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note); // 将笔记对象添加到JSON
+            }
+
+            return js; // 返回JSON对象
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString()); // 记录JSON异常
+            e.printStackTrace();
+        }
+        return null; // 返回null
+    }
+
+    /**
+     * 设置父文件夹ID
+     * 更新笔记的父文件夹ID，并记录需要更新的字段
+     * @param id 父文件夹ID
+     */
+    public void setParentId(long id) {
+        mParentId = id; // 更新父文件夹ID字段
+        mDiffNoteValues.put(NoteColumns.PARENT_ID, id); // 记录需要更新的字段
+    }
+
+    /**
+     * 设置Google Task ID
+     * 更新笔记的Google Task ID，用于同步
+     * @param gid Google Task ID
+     */
+    public void setGtaskId(String gid) {
+        mDiffNoteValues.put(NoteColumns.GTASK_ID, gid); // 记录需要更新的字段
+    }
+
+    /**
+     * 设置同步ID
+     * 更新笔记的同步ID，用于同步控制
+     * @param syncId 同步ID
+     */
+    public void setSyncId(long syncId) {
+        mDiffNoteValues.put(NoteColumns.SYNC_ID, syncId); // 记录需要更新的字段
+    }
+
+    /**
+     * 重置本地修改标记
+     * 将本地修改标记设为0，表示笔记已同步
+     */
+    public void resetLocalModified() {
+        mDiffNoteValues.put(NoteColumns.LOCAL_MODIFIED, 0); // 记录需要更新的字段
+    }
+
+    /**
+     * 获取笔记ID
+     * @return 笔记ID
+     */
+    public long getId() {
+        return mId;
+    }
+
+    /**
+     * 获取父文件夹ID
+     * @return 父文件夹ID
+     */
+    public long getParentId() {
+        return mParentId;
+    }
+
+    /**
+     * 获取笔记摘要
+     * @return 笔记摘要
+     */
+    public String getSnippet() {
+        return mSnippet;
+    }
+
+    /**
+     * 检查笔记是否为普通笔记类型
+     * @return 如果是普通笔记类型返回true，否则返回false
+     */
+    public boolean isNoteType() {
+        return mType == Notes.TYPE_NOTE;
+    }
+
+    /**
+     * 提交笔记更改到数据库
+     * 将笔记对象的更改保存到数据库，包括新建或更新操作
+     * @param validateVersion 是否验证版本号（用于乐观锁控制）
+     */
+    public void commit(boolean validateVersion) {
+        if (mIsCreate) {
+            // 新建笔记操作
+            if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
+                mDiffNoteValues.remove(NoteColumns.ID); // 如果ID为无效值且存在于更新字段中，移除它
+            }
+
+            Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues); // 插入新笔记到数据库
+            try {
+                mId = Long.valueOf(uri.getPathSegments().get(1)); // 从返回的URI中获取新笔记的ID
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString()); // 记录获取ID异常
+                throw new ActionFailureException("create note failed"); // 抛出创建失败异常
+            }
+            if (mId == 0) {
+                throw new IllegalStateException("Create thread id failed"); // 如果ID为0，抛出异常
+            }
+
+            // 如果是普通笔记类型，提交笔记内容数据
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, false, -1); // 提交内容数据，不验证版本
+                }
+            }
+        } else {
+            // 更新笔记操作
+            if (mId <= 0 && mId != Notes.ID_ROOT_FOLDER && mId != Notes.ID_CALL_RECORD_FOLDER) {
+                Log.e(TAG, "No such note"); // 日志记录无效ID
+                throw new IllegalStateException("Try to update note with invalid id"); // 抛出无效ID异常
+            }
+            if (mDiffNoteValues.size() > 0) {
+                mVersion ++; // 版本号递增
+                int result = 0;
+                if (!validateVersion) {
+                    // 不验证版本号，直接更新
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                            + NoteColumns.ID + "=?)", new String[] {
+                            String.valueOf(mId)
+                    });
+                } else {
+                    // 验证版本号，使用乐观锁控制
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                                    + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
+                            new String[] {
+                                    String.valueOf(mId), String.valueOf(mVersion)
+                            });
+                }
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing"); // 日志记录无更新
+                }
+            }
+
+            // 如果是普通笔记类型，提交笔记内容数据的更改
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, validateVersion, mVersion); // 提交内容数据，可能验证版本
+                }
+            }
+        }
+
+        // 重新从数据库加载笔记数据，确保对象状态与数据库一致
+        loadFromCursor(mId);
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent(); // 重新加载笔记内容数据
+
+        mDiffNoteValues.clear(); // 清空更新字段容器
+        mIsCreate = false; // 标记为非新建状态
+    }
+}
\ No newline at end of file
diff --git a/src/gtask/data/Task.java b/src/net/micode/notes/gtask/data/Task.java
similarity index 65%
rename from src/gtask/data/Task.java
rename to src/net/micode/notes/gtask/data/Task.java
index 6a19454..3589281 100644
--- a/src/gtask/data/Task.java
+++ b/src/net/micode/notes/gtask/data/Task.java
@@ -31,65 +31,77 @@ import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-
+/**
+ * Task 类 - 具体任务实体类
+ *
+ * 功能：代表一个具体的便签任务，继承自Node抽象类
+ * 实现便签与Google Tasks同步的具体逻辑，包括创建、更新、同步操作
+ * 处理本地数据库与远程Google Tasks服务器之间的数据映射和转换
+ */
 public class Task extends Node {
-    private static final String TAG = Task.class.getSimpleName();
-
-    private boolean mCompleted;
-
-    private String mNotes;
-
-    private JSONObject mMetaInfo;
-
-    private Task mPriorSibling;
-
-    private TaskList mParent;
-
+    private static final String TAG = Task.class.getSimpleName(); // 日志标签
+
+    // 任务特有属性
+    private boolean mCompleted;        // 完成状态标记
+    private String mNotes;             // 任务备注/描述
+    private JSONObject mMetaInfo;      // 元信息（存储本地便签的详细信息）
+    private Task mPriorSibling;        // 前一个兄弟任务（用于排序）
+    private TaskList mParent;          // 父任务列表（TaskList）
+
+    /**
+     * 默认构造函数，初始化任务属性
+     */
     public Task() {
         super();
-        mCompleted = false;
-        mNotes = null;
-        mPriorSibling = null;
-        mParent = null;
-        mMetaInfo = null;
+        mCompleted = false;    // 默认未完成
+        mNotes = null;         // 默认无备注
+        mPriorSibling = null;  // 默认无前兄弟任务
+        mParent = null;        // 默认无父列表
+        mMetaInfo = null;      // 默认无元信息
     }
 
+    /**
+     * 获取创建任务的JSON操作数据（用于发送到Google Tasks服务器）
+     * @param actionId 操作ID
+     * @return 包含创建操作数据的JSONObject
+     * @throws ActionFailureException 生成JSON失败时抛出
+     */
     public JSONObject getCreateAction(int actionId) {
         JSONObject js = new JSONObject();
 
         try {
-            // action_type
+            // 操作类型：创建
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                     GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
 
-            // action_id
+            // 操作ID
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
 
-            // index
+            // 索引位置（在父列表中的位置）
             js.put(GTaskStringUtils.GTASK_JSON_INDEX, mParent.getChildTaskIndex(this));
 
-            // entity_delta
+            // 实体数据变化
             JSONObject entity = new JSONObject();
-            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
-            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName()); // 任务名称
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null"); // 创建者ID
             entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
-                    GTaskStringUtils.GTASK_JSON_TYPE_TASK);
+                    GTaskStringUtils.GTASK_JSON_TYPE_TASK); // 实体类型为任务
             if (getNotes() != null) {
-                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes()); // 任务备注
             }
             js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
 
-            // parent_id
+            // 父列表ID
             js.put(GTaskStringUtils.GTASK_JSON_PARENT_ID, mParent.getGid());
 
-            // dest_parent_type
+            // 目标父类型
             js.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT_TYPE,
                     GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
 
-            // list_id
+            // 列表ID（与父列表ID相同）
             js.put(GTaskStringUtils.GTASK_JSON_LIST_ID, mParent.getGid());
 
-            // prior_sibling_id
+            // 前兄弟任务ID（用于排序）
             if (mPriorSibling != null) {
                 js.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, mPriorSibling.getGid());
             }
@@ -103,27 +115,33 @@ public class Task extends Node {
         return js;
     }
 
+    /**
+     * 获取更新任务的JSON操作数据（用于发送到Google Tasks服务器）
+     * @param actionId 操作ID
+     * @return 包含更新操作数据的JSONObject
+     * @throws ActionFailureException 生成JSON失败时抛出
+     */
     public JSONObject getUpdateAction(int actionId) {
         JSONObject js = new JSONObject();
 
         try {
-            // action_type
+            // 操作类型：更新
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                     GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
 
-            // action_id
+            // 操作ID
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
 
-            // id
+            // 任务ID
             js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
 
-            // entity_delta
+            // 实体数据变化
             JSONObject entity = new JSONObject();
-            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName()); // 任务名称
             if (getNotes() != null) {
-                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes()); // 任务备注
             }
-            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted()); // 删除状态
             js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
 
         } catch (JSONException e) {
@@ -135,35 +153,40 @@ public class Task extends Node {
         return js;
     }
 
+    /**
+     * 从远程JSON数据设置任务内容（从Google Tasks服务器获取）
+     * @param js 包含远程任务数据的JSONObject
+     * @throws ActionFailureException 解析JSON失败时抛出
+     */
     public void setContentByRemoteJSON(JSONObject js) {
         if (js != null) {
             try {
-                // id
+                // 任务ID
                 if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
                     setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
                 }
 
-                // last_modified
+                // 最后修改时间
                 if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
                     setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
                 }
 
-                // name
+                // 任务名称
                 if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
                     setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
                 }
 
-                // notes
+                // 任务备注
                 if (js.has(GTaskStringUtils.GTASK_JSON_NOTES)) {
                     setNotes(js.getString(GTaskStringUtils.GTASK_JSON_NOTES));
                 }
 
-                // deleted
+                // 删除状态
                 if (js.has(GTaskStringUtils.GTASK_JSON_DELETED)) {
                     setDeleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_DELETED));
                 }
 
-                // completed
+                // 完成状态
                 if (js.has(GTaskStringUtils.GTASK_JSON_COMPLETED)) {
                     setCompleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_COMPLETED));
                 }
@@ -175,6 +198,10 @@ public class Task extends Node {
         }
     }
 
+    /**
+     * 从本地JSON数据设置任务内容（从本地数据库获取）
+     * @param js 包含本地便签数据的JSONObject
+     */
     public void setContentByLocalJSON(JSONObject js) {
         if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)
                 || !js.has(GTaskStringUtils.META_HEAD_DATA)) {
@@ -182,18 +209,21 @@ public class Task extends Node {
         }
 
         try {
+            // 获取便签信息和数据数组
             JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
             JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
 
+            // 验证便签类型
             if (note.getInt(NoteColumns.TYPE) != Notes.TYPE_NOTE) {
                 Log.e(TAG, "invalid type");
                 return;
             }
 
+            // 遍历数据数组，查找便签内容
             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));
+                    setName(data.getString(DataColumns.CONTENT)); // 设置任务名称为便签内容
                     break;
                 }
             }
@@ -204,31 +234,37 @@ public class Task extends Node {
         }
     }
 
+    /**
+     * 从任务内容生成本地JSON数据（用于本地存储）
+     * @return 包含本地便签数据的JSONObject，如果任务无内容则返回null
+     */
     public JSONObject getLocalJSONFromContent() {
         String name = getName();
         try {
             if (mMetaInfo == null) {
-                // new task created from web
+                // 从Web新创建的任务（没有元信息）
                 if (name == null) {
                     Log.w(TAG, "the note seems to be an empty one");
                     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);
+                data.put(DataColumns.CONTENT, name); // 便签内容
                 dataArray.put(data);
                 js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
-                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE); // 类型为普通便签
                 js.put(GTaskStringUtils.META_HEAD_NOTE, note);
                 return js;
             } else {
-                // synced task
+                // 已同步的任务（有元信息）
                 JSONObject note = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
                 JSONArray dataArray = mMetaInfo.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
 
+                // 更新便签内容
                 for (int i = 0; i < dataArray.length(); i++) {
                     JSONObject data = dataArray.getJSONObject(i);
                     if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
@@ -238,7 +274,7 @@ public class Task extends Node {
                 }
 
                 note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
-                return mMetaInfo;
+                return mMetaInfo; // 返回更新后的元信息
             }
         } catch (JSONException e) {
             Log.e(TAG, e.toString());
@@ -247,6 +283,10 @@ public class Task extends Node {
         }
     }
 
+    /**
+     * 设置元信息（从MetaData对象）
+     * @param metaData 元数据对象
+     */
     public void setMetaInfo(MetaData metaData) {
         if (metaData != null && metaData.getNotes() != null) {
             try {
@@ -258,48 +298,57 @@ public class Task extends Node {
         }
     }
 
+    /**
+     * 根据数据库游标确定同步操作类型
+     * @param c 数据库查询结果的Cursor
+     * @return 同步操作状态码（SYNC_ACTION_*）
+     */
     public int getSyncAction(Cursor c) {
         try {
             JSONObject noteInfo = null;
+            // 从元信息中获取便签信息
             if (mMetaInfo != null && mMetaInfo.has(GTaskStringUtils.META_HEAD_NOTE)) {
                 noteInfo = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
             }
 
             if (noteInfo == null) {
                 Log.w(TAG, "it seems that note meta has been deleted");
-                return SYNC_ACTION_UPDATE_REMOTE;
+                return SYNC_ACTION_UPDATE_REMOTE; // 远程更新本地
             }
 
             if (!noteInfo.has(NoteColumns.ID)) {
                 Log.w(TAG, "remote note id seems to be deleted");
-                return SYNC_ACTION_UPDATE_LOCAL;
+                return SYNC_ACTION_UPDATE_LOCAL; // 本地更新远程
             }
 
-            // validate the note id now
+            // 验证便签ID是否匹配
             if (c.getLong(SqlNote.ID_COLUMN) != noteInfo.getLong(NoteColumns.ID)) {
                 Log.w(TAG, "note id doesn't match");
-                return SYNC_ACTION_UPDATE_LOCAL;
+                return SYNC_ACTION_UPDATE_LOCAL; // ID不匹配，用本地更新远程
             }
 
+            // 检查本地修改标记
             if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
-                // there is no local update
+                // 本地无修改
                 if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
-                    // no update both side
+                    // 两边都无更新
                     return SYNC_ACTION_NONE;
                 } else {
-                    // apply remote to local
+                    // 远程有更新，应用到本地
                     return SYNC_ACTION_UPDATE_LOCAL;
                 }
             } else {
-                // validate gtask id
+                // 本地有修改
+                // 验证Google Task 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;
+                    return SYNC_ACTION_ERROR; // ID不匹配，错误
                 }
                 if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
-                    // local modification only
+                    // 仅本地有修改
                     return SYNC_ACTION_UPDATE_REMOTE;
                 } else {
+                    // 两边都有修改，冲突
                     return SYNC_ACTION_UPDATE_CONFLICT;
                 }
             }
@@ -308,44 +357,79 @@ public class Task extends Node {
             e.printStackTrace();
         }
 
-        return SYNC_ACTION_ERROR;
+        return SYNC_ACTION_ERROR; // 发生异常，返回错误
     }
 
+    /**
+     * 判断任务是否值得保存（是否有有效内容）
+     * @return 如果任务有名称或备注则返回true，否则返回false
+     */
     public boolean isWorthSaving() {
         return mMetaInfo != null || (getName() != null && getName().trim().length() > 0)
                 || (getNotes() != null && getNotes().trim().length() > 0);
     }
 
+    /**
+     * 设置完成状态
+     * @param completed 完成状态（true-已完成，false-未完成）
+     */
     public void setCompleted(boolean completed) {
         this.mCompleted = completed;
     }
 
+    /**
+     * 设置任务备注
+     * @param notes 任务备注字符串
+     */
     public void setNotes(String notes) {
         this.mNotes = notes;
     }
 
+    /**
+     * 设置前兄弟任务（用于排序）
+     * @param priorSibling 前兄弟任务对象
+     */
     public void setPriorSibling(Task priorSibling) {
         this.mPriorSibling = priorSibling;
     }
 
+    /**
+     * 设置父任务列表
+     * @param parent 父任务列表对象
+     */
     public void setParent(TaskList parent) {
         this.mParent = parent;
     }
 
+    /**
+     * 获取完成状态
+     * @return 完成状态（true-已完成，false-未完成）
+     */
     public boolean getCompleted() {
         return this.mCompleted;
     }
 
+    /**
+     * 获取任务备注
+     * @return 任务备注字符串
+     */
     public String getNotes() {
         return this.mNotes;
     }
 
+    /**
+     * 获取前兄弟任务
+     * @return 前兄弟任务对象
+     */
     public Task getPriorSibling() {
         return this.mPriorSibling;
     }
 
+    /**
+     * 获取父任务列表
+     * @return 父任务列表对象
+     */
     public TaskList getParent() {
         return this.mParent;
     }
-
-}
+}
\ No newline at end of file
diff --git a/src/gtask/data/TaskList.java b/src/net/micode/notes/gtask/data/TaskList.java
similarity index 66%
rename from src/gtask/data/TaskList.java
rename to src/net/micode/notes/gtask/data/TaskList.java
index 4ea21c5..e096dd8 100644
--- a/src/gtask/data/TaskList.java
+++ b/src/net/micode/notes/gtask/data/TaskList.java
@@ -29,40 +29,54 @@ import org.json.JSONObject;
 
 import java.util.ArrayList;
 
-
+/**
+ * TaskList 类 - 任务列表实体类
+ *
+ * 功能：代表Google Tasks中的一个任务列表（对应小米便签中的文件夹）
+ * 继承自Node抽象类，可以包含多个Task子任务，实现任务列表的层级管理
+ * 处理文件夹与Google Tasks列表的同步，支持子任务的增删改查和排序
+ */
 public class TaskList extends Node {
-    private static final String TAG = TaskList.class.getSimpleName();
+    private static final String TAG = TaskList.class.getSimpleName(); // 日志标签
 
-    private int mIndex;
-
-    private ArrayList<Task> mChildren;
+    private int mIndex;                     // 任务列表在父容器中的索引位置
+    private ArrayList<Task> mChildren;      // 子任务列表
 
+    /**
+     * 默认构造函数，初始化任务列表属性
+     */
     public TaskList() {
         super();
-        mChildren = new ArrayList<Task>();
-        mIndex = 1;
+        mChildren = new ArrayList<Task>(); // 初始化子任务列表
+        mIndex = 1;                        // 默认索引为1（Google Tasks的索引从1开始）
     }
 
+    /**
+     * 获取创建任务列表的JSON操作数据（用于发送到Google Tasks服务器）
+     * @param actionId 操作ID
+     * @return 包含创建操作数据的JSONObject
+     * @throws ActionFailureException 生成JSON失败时抛出
+     */
     public JSONObject getCreateAction(int actionId) {
         JSONObject js = new JSONObject();
 
         try {
-            // action_type
+            // 操作类型：创建
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                     GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
 
-            // action_id
+            // 操作ID
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
 
-            // index
+            // 索引位置
             js.put(GTaskStringUtils.GTASK_JSON_INDEX, mIndex);
 
-            // entity_delta
+            // 实体数据变化
             JSONObject entity = new JSONObject();
-            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
-            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName()); // 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);
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP); // 实体类型为组（列表）
             js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
 
         } catch (JSONException e) {
@@ -74,24 +88,30 @@ public class TaskList extends Node {
         return js;
     }
 
+    /**
+     * 获取更新任务列表的JSON操作数据（用于发送到Google Tasks服务器）
+     * @param actionId 操作ID
+     * @return 包含更新操作数据的JSONObject
+     * @throws ActionFailureException 生成JSON失败时抛出
+     */
     public JSONObject getUpdateAction(int actionId) {
         JSONObject js = new JSONObject();
 
         try {
-            // action_type
+            // 操作类型：更新
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                     GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
 
-            // action_id
+            // 操作ID
             js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
 
-            // id
+            // 列表ID
             js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
 
-            // entity_delta
+            // 实体数据变化
             JSONObject entity = new JSONObject();
-            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
-            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName()); // 列表名称
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted()); // 删除状态
             js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
 
         } catch (JSONException e) {
@@ -103,20 +123,25 @@ public class TaskList extends Node {
         return js;
     }
 
+    /**
+     * 从远程JSON数据设置任务列表内容（从Google Tasks服务器获取）
+     * @param js 包含远程列表数据的JSONObject
+     * @throws ActionFailureException 解析JSON失败时抛出
+     */
     public void setContentByRemoteJSON(JSONObject js) {
         if (js != null) {
             try {
-                // id
+                // 列表ID
                 if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
                     setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
                 }
 
-                // last_modified
+                // 最后修改时间
                 if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
                     setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
                 }
 
-                // name
+                // 列表名称
                 if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
                     setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
                 }
@@ -129,6 +154,10 @@ public class TaskList extends Node {
         }
     }
 
+    /**
+     * 从本地JSON数据设置任务列表内容（从本地数据库获取）
+     * @param js 包含本地文件夹数据的JSONObject
+     */
     public void setContentByLocalJSON(JSONObject js) {
         if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)) {
             Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
@@ -137,10 +166,13 @@ public class TaskList extends Node {
         try {
             JSONObject folder = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
 
+            // 根据文件夹类型设置名称
             if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                // 普通文件夹：使用片段作为名称，并添加MIUI前缀
                 String name = folder.getString(NoteColumns.SNIPPET);
                 setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + name);
             } else if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                // 系统文件夹：根据ID设置特定的名称
                 if (folder.getLong(NoteColumns.ID) == Notes.ID_ROOT_FOLDER)
                     setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT);
                 else if (folder.getLong(NoteColumns.ID) == Notes.ID_CALL_RECORD_FOLDER)
@@ -157,21 +189,28 @@ public class TaskList extends Node {
         }
     }
 
+    /**
+     * 从任务列表内容生成本地JSON数据（用于本地存储）
+     * @return 包含本地文件夹数据的JSONObject
+     */
     public JSONObject getLocalJSONFromContent() {
         try {
             JSONObject js = new JSONObject();
             JSONObject folder = new JSONObject();
 
+            // 处理文件夹名称：移除MIUI前缀
             String folderName = getName();
             if (getName().startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX))
                 folderName = folderName.substring(GTaskStringUtils.MIUI_FOLDER_PREFFIX.length(),
                         folderName.length());
             folder.put(NoteColumns.SNIPPET, folderName);
+
+            // 根据文件夹名称判断类型
             if (folderName.equals(GTaskStringUtils.FOLDER_DEFAULT)
                     || folderName.equals(GTaskStringUtils.FOLDER_CALL_NOTE))
-                folder.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+                folder.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); // 默认文件夹和通话记录文件夹为系统类型
             else
-                folder.put(NoteColumns.TYPE, Notes.TYPE_FOLDER);
+                folder.put(NoteColumns.TYPE, Notes.TYPE_FOLDER); // 其他为普通文件夹
 
             js.put(GTaskStringUtils.META_HEAD_NOTE, folder);
 
@@ -183,28 +222,34 @@ public class TaskList extends Node {
         }
     }
 
+    /**
+     * 根据数据库游标确定同步操作类型
+     * @param c 数据库查询结果的Cursor
+     * @return 同步操作状态码（SYNC_ACTION_*）
+     */
     public int getSyncAction(Cursor c) {
         try {
             if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
-                // there is no local update
+                // 本地无修改
                 if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
-                    // no update both side
+                    // 两边都无更新
                     return SYNC_ACTION_NONE;
                 } else {
-                    // apply remote to local
+                    // 远程有更新，应用到本地
                     return SYNC_ACTION_UPDATE_LOCAL;
                 }
             } else {
-                // validate gtask id
+                // 本地有修改
+                // 验证Google Task 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()) {
-                    // local modification only
+                    // 仅本地有修改
                     return SYNC_ACTION_UPDATE_REMOTE;
                 } else {
-                    // for folder conflicts, just apply local modification
+                    // 文件夹冲突时，优先应用本地修改（不同于任务的处理方式）
                     return SYNC_ACTION_UPDATE_REMOTE;
                 }
             }
@@ -216,16 +261,25 @@ public class TaskList extends Node {
         return SYNC_ACTION_ERROR;
     }
 
+    /**
+     * 获取子任务数量
+     * @return 子任务数量
+     */
     public int getChildTaskCount() {
         return mChildren.size();
     }
 
+    /**
+     * 添加子任务到列表末尾
+     * @param task 要添加的任务
+     * @return 添加成功返回true，失败返回false
+     */
     public boolean addChildTask(Task task) {
         boolean ret = false;
         if (task != null && !mChildren.contains(task)) {
             ret = mChildren.add(task);
             if (ret) {
-                // need to set prior sibling and parent
+                // 设置前兄弟任务和父列表
                 task.setPriorSibling(mChildren.isEmpty() ? null : mChildren
                         .get(mChildren.size() - 1));
                 task.setParent(this);
@@ -234,6 +288,12 @@ public class TaskList extends Node {
         return ret;
     }
 
+    /**
+     * 在指定索引位置添加子任务
+     * @param task 要添加的任务
+     * @param index 要插入的索引位置
+     * @return 添加成功返回true，失败返回false
+     */
     public boolean addChildTask(Task task, int index) {
         if (index < 0 || index > mChildren.size()) {
             Log.e(TAG, "add child task: invalid index");
@@ -244,7 +304,7 @@ public class TaskList extends Node {
         if (task != null && pos == -1) {
             mChildren.add(index, task);
 
-            // update the task list
+            // 更新任务列表的前后兄弟关系
             Task preTask = null;
             Task afterTask = null;
             if (index != 0)
@@ -260,6 +320,11 @@ public class TaskList extends Node {
         return true;
     }
 
+    /**
+     * 从列表中移除子任务
+     * @param task 要移除的任务
+     * @return 移除成功返回true，失败返回false
+     */
     public boolean removeChildTask(Task task) {
         boolean ret = false;
         int index = mChildren.indexOf(task);
@@ -267,11 +332,11 @@ public class TaskList extends Node {
             ret = mChildren.remove(task);
 
             if (ret) {
-                // reset prior sibling and parent
+                // 重置任务的前兄弟任务和父列表
                 task.setPriorSibling(null);
                 task.setParent(null);
 
-                // update the task list
+                // 更新任务列表的前兄弟关系
                 if (index != mChildren.size()) {
                     mChildren.get(index).setPriorSibling(
                             index == 0 ? null : mChildren.get(index - 1));
@@ -281,6 +346,12 @@ public class TaskList extends Node {
         return ret;
     }
 
+    /**
+     * 移动子任务到指定索引位置
+     * @param task 要移动的任务
+     * @param index 目标索引位置
+     * @return 移动成功返回true，失败返回false
+     */
     public boolean moveChildTask(Task task, int index) {
 
         if (index < 0 || index >= mChildren.size()) {
@@ -299,6 +370,11 @@ public class TaskList extends Node {
         return (removeChildTask(task) && addChildTask(task, index));
     }
 
+    /**
+     * 根据Google Task ID查找子任务
+     * @param gid Google Task的全局唯一标识
+     * @return 找到的任务对象，未找到返回null
+     */
     public Task findChildTaskByGid(String gid) {
         for (int i = 0; i < mChildren.size(); i++) {
             Task t = mChildren.get(i);
@@ -309,10 +385,20 @@ public class TaskList extends Node {
         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 任务在列表中的索引，不存在返回-1
+     */
     public int getChildTaskIndex(Task task) {
         return mChildren.indexOf(task);
     }
 
+    /**
+     * 根据索引获取子任务
+     * @param index 子任务索引
+     * @return 指定索引位置的子任务，索引无效返回null
+     */
     public Task getChildTaskByIndex(int index) {
         if (index < 0 || index >= mChildren.size()) {
             Log.e(TAG, "getTaskByIndex: invalid index");
@@ -321,6 +407,11 @@ public class TaskList extends Node {
         return mChildren.get(index);
     }
 
+    /**
+     * 根据Google Task ID获取子任务（方法名有拼写错误）
+     * @param gid Google Task的全局唯一标识
+     * @return 找到的任务对象，未找到返回null
+     */
     public Task getChilTaskByGid(String gid) {
         for (Task task : mChildren) {
             if (task.getGid().equals(gid))
@@ -329,15 +420,27 @@ public class TaskList extends Node {
         return null;
     }
 
+    /**
+     * 获取所有子任务的列表
+     * @return 子任务列表的ArrayList
+     */
     public ArrayList<Task> getChildTaskList() {
         return this.mChildren;
     }
 
+    /**
+     * 设置任务列表索引
+     * @param index 索引值
+     */
     public void setIndex(int index) {
         this.mIndex = index;
     }
 
+    /**
+     * 获取任务列表索引
+     * @return 索引值
+     */
     public int getIndex() {
         return this.mIndex;
     }
-}
+}
\ No newline at end of file
diff --git a/src/gtask/exception/ActionFailureException.java b/src/net/micode/notes/gtask/exception/ActionFailureException.java
similarity index 100%
rename from src/gtask/exception/ActionFailureException.java
rename to src/net/micode/notes/gtask/exception/ActionFailureException.java
diff --git a/src/gtask/exception/NetworkFailureException.java b/src/net/micode/notes/gtask/exception/NetworkFailureException.java
similarity index 100%
rename from src/gtask/exception/NetworkFailureException.java
rename to src/net/micode/notes/gtask/exception/NetworkFailureException.java
diff --git a/src/gtask/remote/GTaskASyncTask.java b/src/net/micode/notes/gtask/remote/GTaskASyncTask.java
similarity index 100%
rename from src/gtask/remote/GTaskASyncTask.java
rename to src/net/micode/notes/gtask/remote/GTaskASyncTask.java
diff --git a/src/gtask/remote/GTaskClient.java b/src/net/micode/notes/gtask/remote/GTaskClient.java
similarity index 100%
rename from src/gtask/remote/GTaskClient.java
rename to src/net/micode/notes/gtask/remote/GTaskClient.java
diff --git a/src/gtask/remote/GTaskManager.java b/src/net/micode/notes/gtask/remote/GTaskManager.java
similarity index 100%
rename from src/gtask/remote/GTaskManager.java
rename to src/net/micode/notes/gtask/remote/GTaskManager.java
diff --git a/src/gtask/remote/GTaskSyncService.java b/src/net/micode/notes/gtask/remote/GTaskSyncService.java
similarity index 100%
rename from src/gtask/remote/GTaskSyncService.java
rename to src/net/micode/notes/gtask/remote/GTaskSyncService.java
diff --git a/src/model/Note.java b/src/net/micode/notes/model/Note.java
similarity index 100%
rename from src/model/Note.java
rename to src/net/micode/notes/model/Note.java
diff --git a/src/model/WorkingNote.java b/src/net/micode/notes/model/WorkingNote.java
similarity index 100%
rename from src/model/WorkingNote.java
rename to src/net/micode/notes/model/WorkingNote.java
diff --git a/src/tool/BackupUtils.java b/src/net/micode/notes/tool/BackupUtils.java
similarity index 100%
rename from src/tool/BackupUtils.java
rename to src/net/micode/notes/tool/BackupUtils.java
diff --git a/src/tool/DataUtils.java b/src/net/micode/notes/tool/DataUtils.java
similarity index 100%
rename from src/tool/DataUtils.java
rename to src/net/micode/notes/tool/DataUtils.java
diff --git a/src/tool/GTaskStringUtils.java b/src/net/micode/notes/tool/GTaskStringUtils.java
similarity index 100%
rename from src/tool/GTaskStringUtils.java
rename to src/net/micode/notes/tool/GTaskStringUtils.java
diff --git a/src/tool/ResourceParser.java b/src/net/micode/notes/tool/ResourceParser.java
similarity index 100%
rename from src/tool/ResourceParser.java
rename to src/net/micode/notes/tool/ResourceParser.java
diff --git a/src/ui/AlarmAlertActivity.java b/src/net/micode/notes/ui/AlarmAlertActivity.java
similarity index 100%
rename from src/ui/AlarmAlertActivity.java
rename to src/net/micode/notes/ui/AlarmAlertActivity.java
diff --git a/src/ui/AlarmInitReceiver.java b/src/net/micode/notes/ui/AlarmInitReceiver.java
similarity index 100%
rename from src/ui/AlarmInitReceiver.java
rename to src/net/micode/notes/ui/AlarmInitReceiver.java
diff --git a/src/ui/AlarmReceiver.java b/src/net/micode/notes/ui/AlarmReceiver.java
similarity index 100%
rename from src/ui/AlarmReceiver.java
rename to src/net/micode/notes/ui/AlarmReceiver.java
diff --git a/src/ui/DateTimePicker.java b/src/net/micode/notes/ui/DateTimePicker.java
similarity index 100%
rename from src/ui/DateTimePicker.java
rename to src/net/micode/notes/ui/DateTimePicker.java
diff --git a/src/ui/DateTimePickerDialog.java b/src/net/micode/notes/ui/DateTimePickerDialog.java
similarity index 100%
rename from src/ui/DateTimePickerDialog.java
rename to src/net/micode/notes/ui/DateTimePickerDialog.java
diff --git a/src/ui/DropdownMenu.java b/src/net/micode/notes/ui/DropdownMenu.java
similarity index 100%
rename from src/ui/DropdownMenu.java
rename to src/net/micode/notes/ui/DropdownMenu.java
diff --git a/src/ui/FoldersListAdapter.java b/src/net/micode/notes/ui/FoldersListAdapter.java
similarity index 100%
rename from src/ui/FoldersListAdapter.java
rename to src/net/micode/notes/ui/FoldersListAdapter.java
diff --git a/src/ui/NoteEditActivity.java b/src/net/micode/notes/ui/NoteEditActivity.java
similarity index 100%
rename from src/ui/NoteEditActivity.java
rename to src/net/micode/notes/ui/NoteEditActivity.java
diff --git a/src/ui/NoteEditText.java b/src/net/micode/notes/ui/NoteEditText.java
similarity index 100%
rename from src/ui/NoteEditText.java
rename to src/net/micode/notes/ui/NoteEditText.java
diff --git a/src/ui/NoteItemData.java b/src/net/micode/notes/ui/NoteItemData.java
similarity index 100%
rename from src/ui/NoteItemData.java
rename to src/net/micode/notes/ui/NoteItemData.java
diff --git a/src/ui/NotesListActivity.java b/src/net/micode/notes/ui/NotesListActivity.java
similarity index 100%
rename from src/ui/NotesListActivity.java
rename to src/net/micode/notes/ui/NotesListActivity.java
diff --git a/src/ui/NotesListAdapter.java b/src/net/micode/notes/ui/NotesListAdapter.java
similarity index 100%
rename from src/ui/NotesListAdapter.java
rename to src/net/micode/notes/ui/NotesListAdapter.java
diff --git a/src/ui/NotesListItem.java b/src/net/micode/notes/ui/NotesListItem.java
similarity index 100%
rename from src/ui/NotesListItem.java
rename to src/net/micode/notes/ui/NotesListItem.java
diff --git a/src/ui/NotesPreferenceActivity.java b/src/net/micode/notes/ui/NotesPreferenceActivity.java
similarity index 100%
rename from src/ui/NotesPreferenceActivity.java
rename to src/net/micode/notes/ui/NotesPreferenceActivity.java
diff --git a/src/widget/NoteWidgetProvider.java b/src/net/micode/notes/widget/NoteWidgetProvider.java
similarity index 100%
rename from src/widget/NoteWidgetProvider.java
rename to src/net/micode/notes/widget/NoteWidgetProvider.java
diff --git a/src/widget/NoteWidgetProvider_2x.java b/src/net/micode/notes/widget/NoteWidgetProvider_2x.java
similarity index 100%
rename from src/widget/NoteWidgetProvider_2x.java
rename to src/net/micode/notes/widget/NoteWidgetProvider_2x.java
diff --git a/src/widget/NoteWidgetProvider_4x.java b/src/net/micode/notes/widget/NoteWidgetProvider_4x.java
similarity index 100%
rename from src/widget/NoteWidgetProvider_4x.java
rename to src/net/micode/notes/widget/NoteWidgetProvider_4x.java