给NotesDatabaseHelper类添加注释

src/mi_note/app/src/main/java/net/micode/notes/data/Notes.java

@@ -22,14 +22,17 @@ import android.net.Uri;
  * @author hzx
  * 版本：1.0
  * 创建日期：2023/10/28
- * 描述：Notes 便签类，封装便签相关的属性和方法
+ * 描述：Notes 便签类，封装便签相关的属性
  */
 public class Notes {
     public static final String AUTHORITY = "micode_notes";
     public static final String TAG = "Notes";
-    public static final int TYPE_NOTE     = 0;  // 便签标识
+    // 便签标识
-    public static final int TYPE_FOLDER   = 1;  // 文件夹标识
+    public static final int TYPE_NOTE     = 0;
-    public static final int TYPE_SYSTEM   = 2;  // 系统标识
+    // 文件夹标识
+    public static final int TYPE_FOLDER   = 1;
+    // 系统标识
+    public static final int TYPE_SYSTEM   = 2;
 
     /**
      * Following IDs are system folders' identifiers
@@ -37,10 +40,14 @@ public class Notes {
      * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
      * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
      */
-    public static final int ID_ROOT_FOLDER = 0;  // 默认的文件夹
+    // 根文件夹标识
-    public static final int ID_TEMPARAY_FOLDER = -1;  // 临时文件夹
+    public static final int ID_ROOT_FOLDER = 0;
-    public static final int ID_CALL_RECORD_FOLDER = -2; // 调用记录文件夹
+    // 临时文件夹标识
-    public static final int ID_TRASH_FOLER = -3;  // 垃圾文件夹
+    public static final int ID_TEMPARAY_FOLDER = -1;
+    // 调用记录文件夹标识
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+    // 垃圾文件夹（回收站）标识
+    public static final int ID_TRASH_FOLER = -3;
 
     public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
     public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
@@ -49,6 +56,7 @@ 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;

src/mi_note/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java

@@ -26,22 +26,35 @@ import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.DataConstants;
 import net.micode.notes.data.Notes.NoteColumns;
 
-
+/**
+ * @author hzx
+ * 版本：1.0
+ * 创建日期：2023/10/28
+ * 描述：NotesDatabaseHelper 便签数据库管理帮助类
+ * 数据库创建与删除、触发器创建与删除、索引创建与删除、数据库升级
+ */
 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;
 
+    // 数据库中的表名接口
     public interface TABLE {
+        // 便签表
         public static final String NOTE = "note";
 
+        // 数据表
         public static final String DATA = "data";
     }
 
     private static final String TAG = "NotesDatabaseHelper";
 
+    // 实例
     private static NotesDatabaseHelper mInstance;
 
+    // 创建便签表的SQL语句字符串常量
     private static final String CREATE_NOTE_TABLE_SQL =
         "CREATE TABLE " + TABLE.NOTE + "(" +
             NoteColumns.ID + " INTEGER PRIMARY KEY," +
@@ -63,6 +76,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
         ")";
 
+    // 创建数据表的SQL语句字符串常量
     private static final String CREATE_DATA_TABLE_SQL =
         "CREATE TABLE " + TABLE.DATA + "(" +
             DataColumns.ID + " INTEGER PRIMARY KEY," +
@@ -78,6 +92,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
         ")";
 
+    // 给数据表中的便签ID字段创建索引的SQL语句字符串常量
     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
@@ -85,6 +100,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Increase folder's note count when move note to the folder
      */
+    // 创建触发器的SQL语句，当便签的父ID改变时，也就是将便签移动到新的文件夹里，将该文件夹的便签数量字段值加1
     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 +
@@ -97,6 +113,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Decrease folder's note count when move note from folder
      */
+    // 创建触发器的SQL语句，把便签从文件夹里移走，该文件夹的便签数量字段值减1
     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 +
@@ -110,6 +127,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Increase folder's note count when insert new note to the folder
      */
+    // 创建触发器的SQL语句，该触发器处理当创建新的便签时，增加便签所处文件夹中便签的数量
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_insert " +
         " AFTER INSERT ON " + TABLE.NOTE +
@@ -122,6 +140,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Decrease folder's note count when delete note from the folder
      */
+    // 创建触发器的SQL语句，该触发器处理当删除便签时，减少对应文件夹便签数量
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
@@ -135,6 +154,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when insert data with type {@link DataConstants#NOTE}
      */
+    // 创建触发器的SQL语句，该触发器处理当插入新文本数据时，便签的文本内容进行更新
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER update_note_content_on_insert " +
         " AFTER INSERT ON " + TABLE.DATA +
@@ -148,6 +168,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when data with {@link DataConstants#NOTE} type has changed
      */
+    // 创建触发器的SQL语句，该触发器处理当更新数据表中的文本数据时，便签表中对应的便签内容进行更新
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_update " +
         " AFTER UPDATE ON " + TABLE.DATA +
@@ -161,6 +182,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when data with {@link DataConstants#NOTE} type has deleted
      */
+    // 创建触发器的SQL语句，数据表中的记录被删除时触发便签表的更新
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_delete " +
         " AFTER delete ON " + TABLE.DATA +
@@ -174,6 +196,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Delete datas belong to note which has been deleted
      */
+    // 创建触发器的SQL语句，便签表的记录被删除时触发数据表对应记录的删除
     private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
         "CREATE TRIGGER delete_data_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
@@ -185,6 +208,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Delete notes belong to folder which has been deleted
      */
+    // 创建触发器的SQL语句，当文件夹被删除时，它所包含的所有便签也被删除
     private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
         "CREATE TRIGGER folder_delete_notes_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
@@ -196,6 +220,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Move notes belong to folder which has been moved to trash folder
      */
+    // 创建触发器的SQL语句，当某文件夹被移入垃圾文件夹中时，其包含的便签或文件夹也被移入垃圾文件夹中
     private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
         "CREATE TRIGGER folder_move_notes_on_trash " +
         " AFTER UPDATE ON " + TABLE.NOTE +
@@ -207,17 +232,30 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     public NotesDatabaseHelper(Context context) {
+        // 初始化数据库
         super(context, DB_NAME, null, DB_VERSION);
     }
 
+    /**
+     * 创建便签表的方法
+     * @param db 数据库操作对象
+     */
     public void createNoteTable(SQLiteDatabase db) {
+        // 执行建表SQL语句，创建便签表
         db.execSQL(CREATE_NOTE_TABLE_SQL);
+        // 初始化创建便签表触发器
         reCreateNoteTableTriggers(db);
+        // 创建系统文件夹
         createSystemFolder(db);
         Log.d(TAG, "note table has been created");
     }
 
+    /**
+     * 重建便签表的所有触发器
+     * @param db 数据库操作对象
+     */
     private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        // 当要创建的便签表触发器存在时，删除该触发器
         db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
         db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
         db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete");
@@ -226,6 +264,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
         db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
 
+        // 重新创建标签表的触发器
         db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
         db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
         db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER);
@@ -235,12 +274,17 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
     }
 
+    /**
+     * 创建系统文件夹的方法，系统文件夹就是根文件夹
+     * @param db 数据库操作对象
+     */
     private void createSystemFolder(SQLiteDatabase db) {
         ContentValues values = new ContentValues();
 
         /**
-         * call record foler for call notes
+         * call record folder for call notes
          */
+        // 创建调用记录文件夹
         values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
@@ -248,6 +292,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         /**
          * root folder which is default folder
          */
+        // 创建根文件夹
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
@@ -256,6 +301,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         /**
          * temporary folder which is used for moving note
          */
+        // 创建临时文件夹
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
@@ -264,29 +310,47 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         /**
          * create trash folder
          */
+        // 创建垃圾文件夹（回收站）
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
     }
 
+    /**
+     * 创建数据表的方法
+     * @param db 数据库操作对象
+     */
     public void createDataTable(SQLiteDatabase db) {
+        // 执行创建数据表的SQL语句
         db.execSQL(CREATE_DATA_TABLE_SQL);
+        // 重建所有的数据表触发器
         reCreateDataTableTriggers(db);
         db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
         Log.d(TAG, "data table has been created");
     }
 
+    /**
+     * 重建所有数据表触发器的方法
+     * @param db 数据库操作对象
+     */
     private void reCreateDataTableTriggers(SQLiteDatabase db) {
+        // 删除已经存在的数据表触发器
         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update");
         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete");
 
+        // 执行创建数据表触发器的SQL语句
         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);
     }
 
+    /**
+     * 获取便签数据库帮助类实例（单例模式）的方法，这是线程安全的方法，同步进行
+     * @param context 上下文
+     * @return 实例
+     */
     static synchronized NotesDatabaseHelper getInstance(Context context) {
         if (mInstance == null) {
             mInstance = new NotesDatabaseHelper(context);
@@ -296,66 +360,96 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
     @Override
     public void onCreate(SQLiteDatabase db) {
+        // 初始化创建便签表和数据表
         createNoteTable(db);
         createDataTable(db);
     }
 
+    /**
+     * 处理数据库升级的方法
+     * @param db 数据库操作对象
+     * @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;
 
         if (oldVersion == 1) {
+            // 升级到版本2，包含了升级到版本3
             upgradeToV2(db);
             skipV2 = true; // this upgrade including the upgrade from v2 to v3
             oldVersion++;
         }
 
         if (oldVersion == 2 && !skipV2) {
+            // 升级到版本3
             upgradeToV3(db);
             reCreateTriggers = true;
             oldVersion++;
         }
 
         if (oldVersion == 3) {
+            // 升级到版本4
             upgradeToV4(db);
             oldVersion++;
         }
 
         if (reCreateTriggers) {
+            // 重新创建所有的触发器
             reCreateNoteTableTriggers(db);
             reCreateDataTableTriggers(db);
         }
 
+        // 升级失败
         if (oldVersion != newVersion) {
             throw new IllegalStateException("Upgrade notes database to version " + newVersion
                     + "fails");
         }
     }
 
+    /**
+     * 数据库升级到版本2的方法  重新创建所有的表
+     * @param db
+     */
     private void upgradeToV2(SQLiteDatabase db) {
+        // 删除表
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        // 创建表
         createNoteTable(db);
         createDataTable(db);
     }
 
+    /**
+     * 数据库升级到版本3的方法  重新创建所有的触发器
+     * @param db
+     */
     private void upgradeToV3(SQLiteDatabase db) {
         // drop unused triggers
+        // 删除没用的触发器
         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");
         // add a column for gtask id
+        // 给便签表增加一个字段gtask_id
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
                 + " TEXT NOT NULL DEFAULT ''");
         // add a trash system folder
+        // 增加一个垃圾文件夹
         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);
     }
 
+    /**
+     * 数据库升级到版本4的方法
+     * @param db 数据库操作对象
+     */
     private void upgradeToV4(SQLiteDatabase db) {
+        // 给便签表增加一个字段version
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
                 + " INTEGER NOT NULL DEFAULT 0");
     }

src/mi_note/app/src/main/java/net/micode/notes/data/NotesProvider.java

@@ -34,7 +34,12 @@ import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
-
+/**
+ * @author hzx
+ * 版本：1.0
+ * 创建日期：2023/10/28
+ * 描述：NotesProvider  便签内容提供者
+ */
 public class NotesProvider extends ContentProvider {
     private static final UriMatcher mMatcher;