data包注释

Notes-master2/src/net/micode/notes/data/NotesDatabaseHelper.java

@@ -27,23 +27,45 @@ import net.micode.notes.data.Notes.DataConstants;
 import net.micode.notes.data.Notes.NoteColumns;
 
 
+/**
+
+该类是Notes应用程序的数据库帮助器类，用于创建和升级应用程序的数据库。
+*/
 public class NotesDatabaseHelper extends SQLiteOpenHelper {
+
+/**
+
+数据库名称
+*/
 private static final String DB_NAME = "note.db";
+/**
 
+数据库版本
+*/
 private static final int DB_VERSION = 4;
+/**
 
+表名称接口
+*/
 public interface TABLE {
 public static final String NOTE = "note";
-
 public static final String DATA = "data";
 }
+/**
 
+日志标签
+*/
 private static final String TAG = "NotesDatabaseHelper";
+/**
 
+数据库帮助器实例
+*/
 private static NotesDatabaseHelper mInstance;
+/**
 
-    private static final String CREATE_NOTE_TABLE_SQL =
-        "CREATE TABLE " + TABLE.NOTE + "(" +
+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," +
@@ -62,9 +84,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 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 + "(" +
+/**
+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," +
@@ -77,28 +100,27 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 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 " +
+/**
+创建DATA表中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 + ");";
-
 /**
-     * Increase folder's note count when move note to the folder
+
+更新NOTE表中PARENT_ID字段时，增加该文件夹的笔记计数器的触发器
 */
-    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
-        "CREATE TRIGGER increase_folder_count_on_update "+
+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
+
+更新NOTE表中PARENT_ID字段时，减少该文件夹的笔记计数器的触发器
 */
-    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
-        "CREATE TRIGGER decrease_folder_count_on_update " +
+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 +
@@ -106,10 +128,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " 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
-     */
+// 插入新笔记时自增父文件夹中笔记数量的触发器
 private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
 "CREATE TRIGGER increase_folder_count_on_insert " +
 " AFTER INSERT ON " + TABLE.NOTE +
@@ -119,9 +138,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
 " END";
 
-    /**
-     * Decrease folder's note count when delete note from the folder
-     */
+// 删除笔记时自减父文件夹中笔记数量的触发器
 private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
 "CREATE TRIGGER decrease_folder_count_on_delete " +
 " AFTER DELETE ON " + TABLE.NOTE +
@@ -132,9 +149,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " AND " + NoteColumns.NOTES_COUNT + ">0;" +
 " END";
 
-    /**
-     * Update note's content when insert data with type {@link DataConstants#NOTE}
-     */
+// 在插入类型为 "note" 的数据时更新笔记内容的触发器
 private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
 "CREATE TRIGGER update_note_content_on_insert " +
 " AFTER INSERT ON " + TABLE.DATA +
@@ -145,9 +160,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
 " END";
 
-    /**
-     * Update note's content when data with {@link DataConstants#NOTE} type has changed
-     */
+// 在更新类型为 "note" 的数据时更新笔记内容的触发器
 private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
 "CREATE TRIGGER update_note_content_on_update " +
 " AFTER UPDATE ON " + TABLE.DATA +
@@ -158,9 +171,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
 " END";
 
-    /**
-     * Update note's content when data with {@link DataConstants#NOTE} type has deleted
-     */
+// 在删除类型为 "note" 的数据时更新笔记内容的触发器
 private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
 "CREATE TRIGGER update_note_content_on_delete " +
 " AFTER delete ON " + TABLE.DATA +
@@ -171,9 +182,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
 " END";
 
-    /**
-     * Delete datas belong to note which has been deleted
-     */
+// 在删除笔记时删除属于该笔记的数据的触发器
 private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
 "CREATE TRIGGER delete_data_on_delete " +
 " AFTER DELETE ON " + TABLE.NOTE +
@@ -182,9 +191,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
 " END";
 
-    /**
-     * Delete notes belong to folder which has been deleted
-     */
+// 在删除文件夹时删除属于该文件夹的笔记的触发器
 private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
 "CREATE TRIGGER folder_delete_notes_on_delete " +
 " AFTER DELETE ON " + TABLE.NOTE +
@@ -193,9 +200,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 " WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
 " END";
 
-    /**
-     * Move notes belong to folder which has been moved to trash folder
-     */
+// 在将文件夹移动到垃圾桶文件夹时移动该文件夹中的笔记的触发器
 private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
 "CREATE TRIGGER folder_move_notes_on_trash " +
 " AFTER UPDATE ON " + TABLE.NOTE +
@@ -210,29 +215,31 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 super(context, DB_NAME, null, DB_VERSION);
 }
 
+// 创建笔记表
 public void createNoteTable(SQLiteDatabase db) {
-        db.execSQL(CREATE_NOTE_TABLE_SQL);
-        reCreateNoteTableTriggers(db);
-        createSystemFolder(db);
-        Log.d(TAG, "note table has been created");
+db.execSQL(CREATE_NOTE_TABLE_SQL); // 创建note表
+reCreateNoteTableTriggers(db); // 重新创建note表的触发器
+createSystemFolder(db); // 创建系统文件夹
+Log.d(TAG, "note table has been created"); // 记录日志，提示note表已被创建
 }
 
+// 重新创建笔记表的触发器
 private void reCreateNoteTableTriggers(SQLiteDatabase db) {
-        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
-        db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
-        db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete");
-        db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete");
-        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert");
-        db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
-        db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
-
-        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
-        db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
-        db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER);
-        db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER);
-        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER);
-        db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER);
-        db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
+db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update"); // 删除更新文件夹计数器触发器
+db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update"); // 删除更新文件夹计数器触发器
+db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete"); // 删除删除文件夹计数器触发器
+db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete"); // 删除删除关联数据触发器
+db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert"); // 删除插入文件夹计数器触发器
+db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete"); // 删除文件夹删除笔记触发器
+db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash"); // 删除移动笔记到回收站触发器
+
+db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER); // 创建更新文件夹计数器触发器
+db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER); // 创建更新文件夹计数器触发器
+db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER); // 创建删除文件夹计数器触发器
+db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER); // 创建删除关联数据触发器
+db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER); // 创建插入文件夹计数器触发器
+db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER); // 创建文件夹删除笔记触发器
+db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER); // 创建移动笔记到回收站触发器
 }
 
 private void createSystemFolder(SQLiteDatabase db) {
@@ -240,6 +247,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
 /**
  * call record foler for call notes
+ * 通话记录文件夹
  */
 values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
 values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
@@ -247,6 +255,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
 /**
  * root folder which is default folder
+ * 默认文件夹
  */
 values.clear();
 values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
@@ -255,6 +264,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
 /**
  * temporary folder which is used for moving note
+ * 用于移动笔记的临时文件夹
  */
 values.clear();
 values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
@@ -263,6 +273,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
 /**
  * create trash folder
+ * 回收站文件夹
  */
 values.clear();
 values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
@@ -271,33 +282,33 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 }
 
 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");
+db.execSQL(CREATE_DATA_TABLE_SQL); // 创建data表
+reCreateDataTableTriggers(db); // 重新创建data表的触发器
+db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL); // 创建data表的note_id索引
+Log.d(TAG, "data table has been created"); // 记录日志，提示data表已被创建
 }
 
 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("DROP TRIGGER IF EXISTS update_note_content_on_insert"); // 删除插入note时更新数据触发器
+db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update"); // 删除更新note时更新数据触发器
+db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete"); // 删除删除note时更新数据触发器
 
-        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER);
-        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER);
-        db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER);
+db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER); // 创建插入note时更新数据触发器
+db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER); // 创建更新note时更新数据触发器
+db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER); // 创建删除note时更新数据触发器
 }
 
 static synchronized NotesDatabaseHelper getInstance(Context context) {
 if (mInstance == null) {
-            mInstance = new NotesDatabaseHelper(context);
+mInstance = new NotesDatabaseHelper(context); // 单例模式，获取NotesDatabaseHelper实例
 }
 return mInstance;
 }
 
 @Override
 public void onCreate(SQLiteDatabase db) {
-        createNoteTable(db);
-        createDataTable(db);
+createNoteTable(db); // 创建note表
+createDataTable(db); // 创建data表
 }
 
 @Override
@@ -306,57 +317,58 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 boolean skipV2 = false;
 
 if (oldVersion == 1) {
-            upgradeToV2(db);
-            skipV2 = true; // this upgrade including the upgrade from v2 to v3
+    upgradeToV2(db); // 更新到版本2
+    skipV2 = true; // 这次更新同时包含版本2到版本3的更新
     oldVersion++;
 }
 
 if (oldVersion == 2 && !skipV2) {
-            upgradeToV3(db);
+    upgradeToV3(db); // 更新到版本3
     reCreateTriggers = true;
     oldVersion++;
 }
 
 if (oldVersion == 3) {
-            upgradeToV4(db);
+    upgradeToV4(db); // 更新到版本4
     oldVersion++;
 }
 
 if (reCreateTriggers) {
-            reCreateNoteTableTriggers(db);
-            reCreateDataTableTriggers(db);
+    reCreateNoteTableTriggers(db); // 重新创建note表触发器
+    reCreateDataTableTriggers(db); // 重新创建data表触发器
 }
 
 if (oldVersion != newVersion) {
     throw new IllegalStateException("Upgrade notes database to version " + newVersion
-                    + "fails");
+            + "fails"); // 如果更新版本不是最新版本，则输出错误信息
 }
 }
 
 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);
+db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE); // 删除note表
+db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA); // 删除data表
+createNoteTable(db); // 创建note表
+createDataTable(db); // 创建data表
 }
 
 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");
+db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert"); // 删除插入note时更新修改日期触发器
+db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_delete"); // 删除删除note时更新修改日期触发器
+db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_update"); // 删除更新note时更新修改日期触发器
+
 // add a column for gtask id
 db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
-                + " TEXT NOT NULL DEFAULT ''");
+        + " TEXT NOT NULL DEFAULT ''"); // 在note表中添加gtask列
+
 // add a trash system folder
 ContentValues values = new ContentValues();
-        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER); // 添加回收站文件夹
 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");
-    }
++ " INTEGER NOT NULL DEFAULT 0"); // 在note表中添加版本列
 }

Notes-master2/src/net/micode/notes/data/NotesProvider.java

@@ -36,22 +36,23 @@ import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
 
 public class NotesProvider extends ContentProvider {
+// 定义UriMatcher，用于匹配Uri
 private static final UriMatcher mMatcher;
-
+// 数据库帮助类
 private NotesDatabaseHelper mHelper;
-
+// 日志标识
 private static final String TAG = "NotesProvider";
-
+// Uri匹配的常量值
 private static final int URI_NOTE = 1;
 private static final int URI_NOTE_ITEM = 2;
 private static final int URI_DATA = 3;
 private static final int URI_DATA_ITEM = 4;
-
 private static final int URI_SEARCH = 5;
 private static final int URI_SEARCH_SUGGEST = 6;
 
 static {
     mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+    // 添加Uri匹配规则
     mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
     mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
     mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
@@ -62,8 +63,7 @@ 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.
+ * 将'\n'字符替换成空格，用于搜索结果标题和内容的显示
  */
 private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
         + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
@@ -73,7 +73,9 @@ public class NotesProvider extends ContentProvider {
         + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
         + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
 
-    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+// 搜索语句
+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
@@ -81,6 +83,7 @@ public class NotesProvider extends ContentProvider {
 
 @Override
 public boolean onCreate() {
+    // 获取数据库帮助类实例
     mHelper = NotesDatabaseHelper.getInstance(getContext());
     return true;
 }
@@ -114,9 +117,9 @@ public class NotesProvider extends ContentProvider {
         case URI_SEARCH_SUGGEST:
             if (sortOrder != null || projection != null) {
                 throw new IllegalArgumentException(
-                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                        "do not specify sortOrder, selection, selectionArgs, or projection"
+                                + "with this query");
             }
-
             String searchString = null;
             if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
                 if (uri.getPathSegments().size() > 1) {
@@ -125,11 +128,9 @@ public class NotesProvider extends ContentProvider {
             } else {
                 searchString = uri.getQueryParameter("pattern");
             }
-
             if (TextUtils.isEmpty(searchString)) {
                 return null;
             }
-
             try {
                 searchString = String.format("%%%s%%", searchString);
                 c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
@@ -142,164 +143,156 @@ public class NotesProvider extends ContentProvider {
             throw new IllegalArgumentException("Unknown URI " + uri);
     }
     if (c != null) {
+        // 设置查询结果发生改变时更新的Uri
         c.setNotificationUri(getContext().getContentResolver(), uri);
     }
     return c;
 }
-
+}
  @Override
 public Uri insert(Uri uri, ContentValues values) {
-        SQLiteDatabase db = mHelper.getWritableDatabase();
-        long dataId = 0, noteId = 0, insertedId = 0;
-        switch (mMatcher.match(uri)) {
-            case URI_NOTE:
-                insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+SQLiteDatabase db = mHelper.getWritableDatabase();//获取写入模式的数据库
+long dataId = 0, noteId = 0, insertedId = 0;//初始化三个变量
+switch (mMatcher.match(uri)) {//根据Uri匹配相应的操作
+case URI_NOTE://如果是Note表
+insertedId = noteId = db.insert(TABLE.NOTE, null, values);//插入数据并获取行号
 break;
-            case URI_DATA:
-                if (values.containsKey(DataColumns.NOTE_ID)) {
-                    noteId = values.getAsLong(DataColumns.NOTE_ID);
+case URI_DATA://如果是Data表
+if (values.containsKey(DataColumns.NOTE_ID)) {//判断是否包含note id
+noteId = values.getAsLong(DataColumns.NOTE_ID);//获取note id
 } else {
-                    Log.d(TAG, "Wrong data format without note id:" + values.toString());
+Log.d(TAG, "Wrong data format without note id:" + values.toString());//打印错误日志
 }
-                insertedId = dataId = db.insert(TABLE.DATA, null, values);
+insertedId = dataId = db.insert(TABLE.DATA, null, values);//插入数据并获取行号
 break;
 default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+throw new IllegalArgumentException("Unknown URI " + uri);//如果Uri不匹配则抛异常
 }
 // Notify the note uri
-        if (noteId > 0) {
-            getContext().getContentResolver().notifyChange(
-                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+if (noteId > 0) {//如果note id不为空
+getContext().getContentResolver().notifyChange(//调用notifyChange方法，通知Uri已经被更改
+ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);//ContentUris.withAppendedId方法是在后面添加一个id，用来获取Uri
 }
-
 // Notify the data uri
-        if (dataId > 0) {
-            getContext().getContentResolver().notifyChange(
-                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+if (dataId > 0) {//如果data id不为空
+getContext().getContentResolver().notifyChange(//调用notifyChange方法，通知Uri已经被更改
+ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);//ContentUris.withAppendedId方法是在后面添加一个id，用来获取Uri
 }
-
-        return ContentUris.withAppendedId(uri, insertedId);
+return ContentUris.withAppendedId(uri, insertedId);//最终返回更新后的Uri
 }
 
 @Override
 public int delete(Uri uri, String selection, String[] selectionArgs) {
 int count = 0;
 String id = null;
-        SQLiteDatabase db = mHelper.getWritableDatabase();
-        boolean deleteData = false;
-        switch (mMatcher.match(uri)) {
-            case URI_NOTE:
-                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
-                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+SQLiteDatabase db = mHelper.getWritableDatabase();//获取写入模式的数据库
+boolean deleteData = false;//初始化deleteData变量
+switch (mMatcher.match(uri)) {//根据Uri匹配相应的操作
+case URI_NOTE://如果是Note表
+selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";//删除条件
+count = db.delete(TABLE.NOTE, selection, selectionArgs);//删除数据，并获取删除行数
 break;
 case URI_NOTE_ITEM:
-                id = uri.getPathSegments().get(1);
-                /**
-                 * ID that smaller than 0 is system folder which is not allowed to
-                 * trash
-                 */
-                long noteId = Long.valueOf(id);
+id = uri.getPathSegments().get(1);//获取Uri中的id
+/*ID that smaller than 0 is system folder which is not allowed to trash*/
+long noteId = Long.valueOf(id);//将id转化为long类型
 if (noteId <= 0) {
 break;
 }
 count = db.delete(TABLE.NOTE,
-                        NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);//删除数据，并获取删除行数
 break;
-            case URI_DATA:
-                count = db.delete(TABLE.DATA, selection, selectionArgs);
-                deleteData = true;
+case URI_DATA://如果是Data表
+count = db.delete(TABLE.DATA, selection, selectionArgs);//删除数据，并获取删除行数
+deleteData = true;//deleteData为true
 break;
 case URI_DATA_ITEM:
-                id = uri.getPathSegments().get(1);
+id = uri.getPathSegments().get(1);//获取Uri中的id
 count = db.delete(TABLE.DATA,
-                        DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
-                deleteData = true;
+DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);//删除数据，并获取删除行数
+deleteData = true;//deleteData为true
 break;
 default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+throw new IllegalArgumentException("Unknown URI " + uri);//如果Uri不匹配则抛异常
 }
-        if (count > 0) {
-            if (deleteData) {
-                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+if (count > 0) {//如果删除行数大于0
+if (deleteData) {//如果是Data表
+getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);//调用notifyChange方法，通知Uri已经被更改
 }
-            getContext().getContentResolver().notifyChange(uri, null);
+getContext().getContentResolver().notifyChange(uri, null);//调用notifyChange方法，通知Uri已经被更改
 }
-        return count;
+return count;//返回删除行数
 }
 
 @Override
 public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
 int count = 0;
 String id = null;
-        SQLiteDatabase db = mHelper.getWritableDatabase();
-        boolean updateData = false;
-        switch (mMatcher.match(uri)) {
-            case URI_NOTE:
-                increaseNoteVersion(-1, selection, selectionArgs);
-                count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+SQLiteDatabase db = mHelper.getWritableDatabase();//获取写入模式的数据库
+boolean updateData = false;//初始化updateData变量
+switch (mMatcher.match(uri)) {//根据Uri匹配相应的操作
+case URI_NOTE://如果是Note表
+increaseNoteVersion(-1, selection, selectionArgs);//更新版本号
+count = db.update(TABLE.NOTE, values, selection, selectionArgs);//更新数据，并获取更新行数
 break;
 case URI_NOTE_ITEM:
-                id = uri.getPathSegments().get(1);
-                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+id = uri.getPathSegments().get(1);//获取Uri中的id
+increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);//更新版本号
 count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
-                        + parseSelection(selection), selectionArgs);
++ parseSelection(selection), selectionArgs);//更新数据，并获取更新行数
 break;
-            case URI_DATA:
-                count = db.update(TABLE.DATA, values, selection, selectionArgs);
-                updateData = true;
+case URI_DATA://如果是Data表
+count = db.update(TABLE.DATA, values, selection, selectionArgs);//更新数据，并获取更新行数
+updateData = true;//updateData为true
 break;
 case URI_DATA_ITEM:
-                id = uri.getPathSegments().get(1);
+id = uri.getPathSegments().get(1);//获取Uri中的id
 count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
-                        + parseSelection(selection), selectionArgs);
-                updateData = true;
++ parseSelection(selection), selectionArgs);//更新数据，并获取更新行数
+updateData = true;//updateData为true
 break;
 default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+throw new IllegalArgumentException("Unknown URI " + uri);//如果Uri不匹配则抛异常
 }
-
-        if (count > 0) {
-            if (updateData) {
-                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+if (count > 0) {//如果更新行数大于0
+if (updateData) {//如果是Data表
+getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);//调用notifyChange方法，通知Uri已经被更改
 }
-            getContext().getContentResolver().notifyChange(uri, null);
+getContext().getContentResolver().notifyChange(uri, null);//调用notifyChange方法，通知Uri已经被更改
 }
-        return count;
+return count;//返回更新行数
 }
 
 private String parseSelection(String selection) {
-        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");//解析选择条件
 }
 
 private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
-        StringBuilder sql = new StringBuilder(120);
+StringBuilder sql = new StringBuilder(120);//创建一个StringBuilder
 sql.append("UPDATE ");
-        sql.append(TABLE.NOTE);
+sql.append(TABLE.NOTE);//更新Note表
 sql.append(" SET ");
 sql.append(NoteColumns.VERSION);
-        sql.append("=" + NoteColumns.VERSION + "+1 ");
-
-        if (id > 0 || !TextUtils.isEmpty(selection)) {
-            sql.append(" WHERE ");
+sql.append("=" + NoteColumns.VERSION + "+1 ");//版本号加1
+if (id > 0 || !TextUtils.isEmpty(selection)) {//如果id大于0或有选择条件
+sql.append(" WHERE ");//添加WHERE子句
 }
-        if (id > 0) {
-            sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+if (id > 0) {//如果id大于0
+sql.append(NoteColumns.ID + "=" + String.valueOf(id));//更新对应的id
 }
-        if (!TextUtils.isEmpty(selection)) {
+if (!TextUtils.isEmpty(selection)) {//如果选择条件不为空
 String selectString = id > 0 ? parseSelection(selection) : selection;
 for (String args : selectionArgs) {
-                selectString = selectString.replaceFirst("\\?", args);
+selectString = selectString.replaceFirst("\?", args);
 }
-            sql.append(selectString);
+sql.append(selectString);//解析选择条件并添加进sql中
 }
-
-        mHelper.getWritableDatabase().execSQL(sql.toString());
+mHelper.getWritableDatabase().execSQL(sql.toString());//执行sql语句
 }
 
 @Override
 public String getType(Uri uri) {
 // TODO Auto-generated method stub
-        return null;
+return null;//返回空类型
 }
 
-}