diff --git a/src/net/micode/notes/gtask/data/MetaData.java b/src/net/micode/notes/gtask/data/MetaData.java
index b0bbe62..0789be1 100644
--- a/src/net/micode/notes/gtask/data/MetaData.java
+++ b/src/net/micode/notes/gtask/data/MetaData.java
@@ -31,33 +31,39 @@ public class MetaData extends Task {
     private String mRelatedGid = null;
 
     public void setMeta(String gid, JSONObject metaInfo) {
+//调用JSONObject库函数put ()，Task类中的setNotes ()和setName ()函数生成元数据库
+
         try {
             metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
         } catch (JSONException e) {
-            Log.e(TAG, "failed to put related gid");
+            Log.e(TAG, "failed to put related gid");//输出错误信息
         }
         setNotes(metaInfo.toString());
         setName(GTaskStringUtils.META_NOTE_NAME);
     }
 
     public String getRelatedGid() {
+//获取相关联的Gid
         return mRelatedGid;
     }
 
     @Override
     public boolean isWorthSaving() {
+//判断当前数据是否为空，若为空则返回真即值得保存
         return getNotes() != null;
     }
 
     @Override
     public void setContentByRemoteJSON(JSONObject js) {
+//使用远程json数据对象设置元数据内容
         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");
+                Log.w(TAG, "failed to get related gid");//输出警告信息
+
                 mRelatedGid = null;
             }
         }
@@ -66,16 +72,19 @@ public class MetaData extends Task {
     @Override
     public void setContentByLocalJSON(JSONObject js) {
         // this function should not be called
-        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+//使用本地json数据对象设置元数据内容
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");//传递非法参数异常
     }
 
     @Override
     public JSONObject getLocalJSONFromContent() {
+//从元数据内容中获取本地json对象
         throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
     }
 
     @Override
     public int getSyncAction(Cursor c) {
+//获取同步动作状态
         throw new IllegalAccessError("MetaData:getSyncAction should not be called");
     }
 
diff --git a/src/net/micode/notes/gtask/data/Node.java b/src/net/micode/notes/gtask/data/Node.java
index 63950e0..48dee83 100644
--- a/src/net/micode/notes/gtask/data/Node.java
+++ b/src/net/micode/notes/gtask/data/Node.java
@@ -21,6 +21,7 @@ import android.database.Cursor;
 import org.json.JSONObject;
 
 public abstract class Node {
+//定义了各种用于表征同步状态的常量
     public static final int SYNC_ACTION_NONE = 0;
 
     public static final int SYNC_ACTION_ADD_REMOTE = 1;
diff --git a/src/net/micode/notes/gtask/data/SqlData.java b/src/net/micode/notes/gtask/data/SqlData.java
index d3ec3be..b502e04 100644
--- a/src/net/micode/notes/gtask/data/SqlData.java
+++ b/src/net/micode/notes/gtask/data/SqlData.java
@@ -36,6 +36,7 @@ import org.json.JSONObject;
 
 
 public class SqlData {
+//得到类的简写名称存入字符串TAG中
     private static final String TAG = SqlData.class.getSimpleName();
 
     private static final int INVALID_ID = -99999;
@@ -72,6 +73,7 @@ public class SqlData {
     private ContentValues mDiffDataValues;
 
     public SqlData(Context context) {
+//构造函数，用于初始化数据
         mContentResolver = context.getContentResolver();
         mIsCreate = true;
         mDataId = INVALID_ID;
@@ -83,6 +85,7 @@ public class SqlData {
     }
 
     public SqlData(Context context, Cursor c) {
+//构造函数，用于初始化数据
         mContentResolver = context.getContentResolver();
         mIsCreate = false;
         loadFromCursor(c);
@@ -90,6 +93,7 @@ public class SqlData {
     }
 
     private void loadFromCursor(Cursor c) {
+//从当前的光标处将五列的数据加载到该类的对象
         mDataId = c.getLong(DATA_ID_COLUMN);
         mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN);
         mDataContent = c.getString(DATA_CONTENT_COLUMN);
@@ -98,6 +102,7 @@ public class SqlData {
     }
 
     public void setContent(JSONObject js) throws JSONException {
+//设置用于共享的数据
         long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID;
         if (mIsCreate || mDataId != dataId) {
             mDiffDataValues.put(DataColumns.ID, dataId);
@@ -131,6 +136,7 @@ public class SqlData {
     }
 
     public JSONObject getContent() throws JSONException {
+//获取共享的数据内容
         if (mIsCreate) {
             Log.e(TAG, "it seems that we haven't created this in database yet");
             return null;
@@ -145,7 +151,7 @@ public class SqlData {
     }
 
     public void commit(long noteId, boolean validateVersion, long version) {
-
+//把当前造作所做的修改保存到数据库
         if (mIsCreate) {
             if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) {
                 mDiffDataValues.remove(DataColumns.ID);
@@ -184,6 +190,7 @@ public class SqlData {
     }
 
     public long getId() {
+//获取当前id
         return mDataId;
     }
 }
diff --git a/src/net/micode/notes/gtask/data/SqlNote.java b/src/net/micode/notes/gtask/data/SqlNote.java
index 79a4095..c10e219 100644
--- a/src/net/micode/notes/gtask/data/SqlNote.java
+++ b/src/net/micode/notes/gtask/data/SqlNote.java
@@ -39,6 +39,7 @@ import java.util.ArrayList;
 
 
 public class SqlNote {
+//得到类的简写名称存入字符串TAG中
     private static final String TAG = SqlNote.class.getSimpleName();
 
     private static final int INVALID_ID = -99999;
@@ -123,6 +124,7 @@ public class SqlNote {
     private ArrayList<SqlData> mDataList;
 
     public SqlNote(Context context) {
+//构造函数
         mContext = context;
         mContentResolver = context.getContentResolver();
         mIsCreate = true;
@@ -144,6 +146,7 @@ public class SqlNote {
     }
 
     public SqlNote(Context context, Cursor c) {
+//构造函数
         mContext = context;
         mContentResolver = context.getContentResolver();
         mIsCreate = false;
@@ -167,6 +170,7 @@ public class SqlNote {
     }
 
     private void loadFromCursor(long id) {
+//
         Cursor c = null;
         try {
             c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",