new annotation

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

@@ -36,6 +36,7 @@ import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
 
 public class NotesProvider extends ContentProvider {
+	//为存储和获取数据提供接口
     private static final UriMatcher mMatcher;
 
     private NotesDatabaseHelper mHelper;
@@ -59,7 +60,7 @@ public class NotesProvider extends ContentProvider {
         mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
         mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
         mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
-    }
+    }// 把需要匹配Uri路径全部给注册上
 
     /**
      * x'0A' represents the '\n' character in sqlite. For title and content in the search result,
@@ -72,24 +73,26 @@ public class NotesProvider extends ContentProvider {
         + 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;
+    //定义常量
 
     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;
+    //定义常量
 
     @Override
     public boolean onCreate() {
         mHelper = NotesDatabaseHelper.getInstance(getContext());
         return true;
-    }
+    }//实例化mHelper
 
     @Override
     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
             String sortOrder) {
         Cursor c = null;
-        SQLiteDatabase db = mHelper.getReadableDatabase();
+        SQLiteDatabase db = mHelper.getReadableDatabase();//get数据库
         String id = null;
         switch (mMatcher.match(uri)) {
             case URI_NOTE:
@@ -115,7 +118,7 @@ public class NotesProvider extends ContentProvider {
                 if (sortOrder != null || projection != null) {
                     throw new IllegalArgumentException(
                             "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
-                }
+                }//抛出数据异常
 
                 String searchString = null;
                 if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
@@ -139,17 +142,17 @@ public class NotesProvider extends ContentProvider {
                 }
                 break;
             default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
-        }
+                throw new IllegalArgumentException("Unknown URI " + uri);//抛出URI异常
+        }//查找Uri
         if (c != null) {
             c.setNotificationUri(getContext().getContentResolver(), uri);
         }
         return c;
-    }
+    }// 查询uri在数据库中对应的位置
 
     @Override
     public Uri insert(Uri uri, ContentValues values) {
-        SQLiteDatabase db = mHelper.getWritableDatabase();
+        SQLiteDatabase db = mHelper.getWritableDatabase();//get数据库
         long dataId = 0, noteId = 0, insertedId = 0;
         switch (mMatcher.match(uri)) {
             case URI_NOTE:
@@ -164,7 +167,7 @@ public class NotesProvider extends ContentProvider {
                 insertedId = dataId = db.insert(TABLE.DATA, null, values);
                 break;
             default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+                throw new IllegalArgumentException("Unknown URI " + uri);//抛出URI异常
         }
         // Notify the note uri
         if (noteId > 0) {
@@ -178,14 +181,14 @@ public class NotesProvider extends ContentProvider {
                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
         }
 
-        return ContentUris.withAppendedId(uri, insertedId);
+        return ContentUris.withAppendedId(uri, insertedId);//返回uri的路径
     }
 
     @Override
-    public int delete(Uri uri, String selection, String[] selectionArgs) {
+    public int delete(Uri uri, String selection, String[] selectionArgs) {//删除URI
         int count = 0;
         String id = null;
-        SQLiteDatabase db = mHelper.getWritableDatabase();
+        SQLiteDatabase db = mHelper.getWritableDatabase();//get数据库
         boolean deleteData = false;
         switch (mMatcher.match(uri)) {
             case URI_NOTE:
@@ -216,7 +219,7 @@ public class NotesProvider extends ContentProvider {
                 deleteData = true;
                 break;
             default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+                throw new IllegalArgumentException("Unknown URI " + uri);//抛出URI异常
         }
         if (count > 0) {
             if (deleteData) {
@@ -228,7 +231,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {//更新
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
@@ -269,7 +272,7 @@ public class NotesProvider extends ContentProvider {
 
     private String parseSelection(String selection) {
         return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
-    }
+    }//字符串变成规定格式
 
     private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
         StringBuilder sql = new StringBuilder(120);
@@ -294,7 +297,7 @@ public class NotesProvider extends ContentProvider {
         }
 
         mHelper.getWritableDatabase().execSQL(sql.toString());
-    }
+    } //升级
 
     @Override
     public String getType(Uri uri) {