精读了remote和tool中java源代码

src/Notes-master/app/src/main/java/net/micode/notes/gtask/remote/GTaskASyncTask.java

@@ -29,7 +29,7 @@ import net.micode.notes.ui.NotesListActivity;
 import net.micode.notes.ui.NotesPreferenceActivity;
 
 
-public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
+public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {   //异步操作类，实现Gtask异步操作过程
 
     private static int GTASK_SYNC_NOTIFICATION_ID = 5234235;
 
@@ -57,7 +57,7 @@ public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
         mTaskManager.cancelSync();
     }
 
-    public void publishProgess(String message) {
+    public void publishProgess(String message) {//发布进度单位，系统将会调用onProgressUpdate()方法更新这些值
         publishProgress(new String[] {
             message
         });
@@ -82,13 +82,13 @@ public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
 //        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);
 //    }
 
-    private void showNotification(int tickerId, String content) {
+    private void showNotification(int tickerId, String content) {//向用户提示当前同步的状态，是一个交互的方法
         PendingIntent pendingIntent;
-        if (tickerId != R.string.ticker_success) {
+        if (tickerId != R.string.ticker_success) {//如果同步不成功，那么从系统取得一个用于启动一个NotesPreferenceActivity的PendingIntent对象
             pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
                     NotesPreferenceActivity.class), 0);
 
-        } else {
+        } else {//如果同步成功，那么从系统取得一个用于启动一个NotesListActivity的PendingIntent对象
             pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
                     NotesListActivity.class), 0);
         }
@@ -102,17 +102,17 @@ public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
                 .setWhen(System.currentTimeMillis())
                 .setOngoing(true);
         Notification notification=builder.getNotification();
-        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);
+        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);//通过NotificationManager对象的notify（）方法来执行一个notification的消息
     }
     @Override
-    protected Integer doInBackground(Void... unused) {
+    protected Integer doInBackground(Void... unused) {//完成任务的主要工作
         publishProgess(mContext.getString(R.string.sync_progress_login, NotesPreferenceActivity
                 .getSyncAccountName(mContext)));
         return mTaskManager.sync(mContext, this);
     }
 
     @Override
-    protected void onProgressUpdate(String... progress) {
+    protected void onProgressUpdate(String... progress) {//显示任务执行进度，增加进度条的功能
         showNotification(R.string.ticker_syncing, progress[0]);
         if (mContext instanceof GTaskSyncService) {
             ((GTaskSyncService) mContext).sendBroadcast(progress[0]);
@@ -120,7 +120,7 @@ public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
     }
 
     @Override
-    protected void onPostExecute(Integer result) {
+    protected void onPostExecute(Integer result) {//得到结果处理操作ui，管理操作ui的方式
         if (result == GTaskManager.STATE_SUCCESS) {
             showNotification(R.string.ticker_success, mContext.getString(
                     R.string.success_sync_account, mTaskManager.getSyncAccount()));
@@ -138,7 +138,7 @@ public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
 
                 public void run() {
                     mOnCompleteListener.onComplete();
-                }
+                }//完成后的操作，使用onComplete()将所有值都重新初始化，相当于完成一次操作
             }).start();
         }
     }

src/Notes-master/app/src/main/java/net/micode/notes/gtask/remote/GTaskClient.java

@@ -60,7 +60,7 @@ import java.util.zip.GZIPInputStream;
 import java.util.zip.Inflater;
 import java.util.zip.InflaterInputStream;
 
-
+//主要功能：实现GTASK的登录操作，进行GTASK任务的创建，创建任务列表，从网络上获取任务和任务列表的内容
 public class GTaskClient {
     private static final String TAG = GTaskClient.class.getSimpleName();
 
@@ -102,49 +102,51 @@ public class GTaskClient {
         mUpdateArray = null;
     }
 
-    public static synchronized GTaskClient getInstance() {
+    public static synchronized GTaskClient getInstance() {//用来获取的实例化对象
         if (mInstance == null) {
             mInstance = new GTaskClient();
         }
         return mInstance;
     }
 
-    public boolean login(Activity activity) {
+    public boolean login(Activity activity) {//实现登录操作的函数，传入参数activity
         // we suppose that the cookie would expire after 5 minutes
         // then we need to re-login
-        final long interval = 1000 * 60 * 5;
+        final long interval = 1000 * 60 * 5;//判断最后一次登录是否超过五分钟
         if (mLastLoginTime + interval < System.currentTimeMillis()) {
             mLoggedin = false;
         }
 
         // need to re-login after account switch
+        // 重新登录
         if (mLoggedin
                 && !TextUtils.equals(getSyncAccount().name, NotesPreferenceActivity
                         .getSyncAccountName(activity))) {
             mLoggedin = false;
         }
-
+        //如果没超时就不用登录
         if (mLoggedin) {
             Log.d(TAG, "already logged in");
             return true;
         }
 
-        mLastLoginTime = System.currentTimeMillis();
-        String authToken = loginGoogleAccount(activity, false);
+        mLastLoginTime = System.currentTimeMillis();//更新登录时间即为系统时间
+        String authToken = loginGoogleAccount(activity, false);//判断是否登录google账户
         if (authToken == null) {
             Log.e(TAG, "login google account failed");
             return false;
         }
 
         // login with custom domain if necessary
-        if (!(mAccount.name.toLowerCase().endsWith("gmail.com") || mAccount.name.toLowerCase()
-                .endsWith("googlemail.com"))) {
+        //尝试使用用户自己的域名登录
+        if (!(mAccount.name.toLowerCase().endsWith("gmail.com") || mAccount.name.toLowerCase()//将用户名改为统一格式后判断是否为googl账户
+                .endsWith("googlemail.com"))) {//
             StringBuilder url = new StringBuilder(GTASK_URL).append("a/");
             int index = mAccount.name.indexOf('@') + 1;
             String suffix = mAccount.name.substring(index);
             url.append(suffix + "/");
-            mGetUrl = url.toString() + "ig";
-            mPostUrl = url.toString() + "r/ig";
+            mGetUrl = url.toString() + "ig";//设置用户对应的geturl
+            mPostUrl = url.toString() + "r/ig";//设置用户对应的posturl
 
             if (tryToLoginGtask(activity, authToken)) {
                 mLoggedin = true;
@@ -152,6 +154,7 @@ public class GTaskClient {
         }
 
         // try to login with google official url
+        //如果用户无法登录使用官方的url进行登录
         if (!mLoggedin) {
             mGetUrl = GTASK_GET_URL;
             mPostUrl = GTASK_POST_URL;
@@ -163,11 +166,14 @@ public class GTaskClient {
         mLoggedin = true;
         return true;
     }
-
-    private String loginGoogleAccount(Activity activity, boolean invalidateToken) {
+    //具体实现登录账户方法
+    //使用令牌
+    //使用accountmanager进行管理注册账号
+    //返回账号的令牌
+    private String loginGoogleAccount(Activity activity, boolean invalidateToken) {//使用令牌登录google账号
         String authToken;
-        AccountManager accountManager = AccountManager.get(activity);
-        Account[] accounts = accountManager.getAccountsByType("com.google");
+        AccountManager accountManager = AccountManager.get(activity);//提供给用户注册的接口
+        Account[] accounts = accountManager.getAccountsByType("com.google");//获取全部以com.google结尾的account
 
         if (accounts.length == 0) {
             Log.e(TAG, "there is no available google account");
@@ -176,6 +182,7 @@ public class GTaskClient {
 
         String accountName = NotesPreferenceActivity.getSyncAccountName(activity);
         Account account = null;
+        //查询是否已经注册过，查找注册库信息
         for (Account a : accounts) {
             if (a.name.equals(accountName)) {
                 account = a;
@@ -190,6 +197,7 @@ public class GTaskClient {
         }
 
         // get the token now
+        //获取选中账号的令牌
         AccountManagerFuture<Bundle> accountManagerFuture = accountManager.getAuthToken(account,
                 "goanna_mobile", null, activity, null, null);
         try {
@@ -204,9 +212,9 @@ public class GTaskClient {
             authToken = null;
         }
 
-        return authToken;
+        return authToken;//令牌
     }
-
+    //尝试登陆Gtask，这只是一个预先判断令牌是否是有效以及是否能登上GTask的方法,而不是具体实现登陆的方法
     private boolean tryToLoginGtask(Activity activity, String authToken) {
         if (!loginGtask(authToken)) {
             // maybe the auth token is out of date, now let's invalidate the
@@ -224,26 +232,27 @@ public class GTaskClient {
         }
         return true;
     }
-
+    //实现登录GTask的具体操作
     private boolean loginGtask(String authToken) {
         int timeoutConnection = 10000;
-        int timeoutSocket = 15000;
+        int timeoutSocket = 15000;//socket是一种通信连接实现数据的交换的端口
         HttpParams httpParameters = new BasicHttpParams();
-        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
-        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
+        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);//设置连接超时时间
+        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);//设置设置端口超时时间
         mHttpClient = new DefaultHttpClient(httpParameters);
-        BasicCookieStore localBasicCookieStore = new BasicCookieStore();
+        BasicCookieStore localBasicCookieStore = new BasicCookieStore();//设置本地cookie
         mHttpClient.setCookieStore(localBasicCookieStore);
         HttpProtocolParams.setUseExpectContinue(mHttpClient.getParams(), false);
 
         // login gtask
         try {
-            String loginUrl = mGetUrl + "?auth=" + authToken;
-            HttpGet httpGet = new HttpGet(loginUrl);
+            String loginUrl = mGetUrl + "?auth=" + authToken;//设置登录的url
+            HttpGet httpGet = new HttpGet(loginUrl);//通过登录的uri实例化网页上资源的查找
             HttpResponse response = null;
             response = mHttpClient.execute(httpGet);
 
             // get the cookie now
+            //获取CookieStore里存放的cookie
             List<Cookie> cookies = mHttpClient.getCookieStore().getCookies();
             boolean hasAuthCookie = false;
             for (Cookie cookie : cookies) {
@@ -256,6 +265,7 @@ public class GTaskClient {
             }
 
             // get the client version
+            //获取client的内容，具体操作是在返回的Content中截取从_setup(开始到)}</script>中间的字符串内容，也就是gtask_url的内容
             String resString = getResponseContent(response.getEntity());
             String jsBegin = "_setup(";
             String jsEnd = ")}</script>";
@@ -290,7 +300,7 @@ public class GTaskClient {
         httpPost.setHeader("AT", "1");
         return httpPost;
     }
-
+    //通过URL获取响应后返回的数据，也就是网络上的数据和资源
     private String getResponseContent(HttpEntity entity) throws IOException {
         String contentEncoding = null;
         if (entity.getContentEncoding() != null) {
@@ -299,7 +309,7 @@ public class GTaskClient {
         }
 
         InputStream input = entity.getContent();
-        if (contentEncoding != null && contentEncoding.equalsIgnoreCase("gzip")) {
+        if (contentEncoding != null && contentEncoding.equalsIgnoreCase("gzip")) {//压缩数据库
             input = new GZIPInputStream(entity.getContent());
         } else if (contentEncoding != null && contentEncoding.equalsIgnoreCase("deflate")) {
             Inflater inflater = new Inflater(true);
@@ -322,7 +332,10 @@ public class GTaskClient {
             input.close();
         }
     }
-
+     //通过JSON发送请求，请求的具体内容在json的实例化对象js中然后传入
+     // 利用UrlEncodedFormEntity entity和httpPost.setEntity(entity)方法把js中的内容放置到httpPost中
+     //执行请求后使用getResponseContent方法得到返回的数据和资源
+     // 将资源再次放入json后返回
     private JSONObject postRequest(JSONObject js) throws NetworkFailureException {
         if (!mLoggedin) {
             Log.e(TAG, "please login first");
@@ -359,7 +372,7 @@ public class GTaskClient {
             throw new ActionFailureException("error occurs when posting request");
         }
     }
-
+    //创建单个任务，传入的参数是.gtask.data.task包里的task类对象，利用json获取task里的内容，并且创建相应的jsPost
     public void createTask(Task task) throws NetworkFailureException {
         commitUpdate();
         try {
@@ -385,7 +398,7 @@ public class GTaskClient {
             throw new ActionFailureException("create task: handing jsonobject failed");
         }
     }
-
+    //创建一个任务列表，与createTask几乎一样，区别就是最后设置的是tasklist的gid
     public void createTaskList(TaskList tasklist) throws NetworkFailureException {
         commitUpdate();
         try {
@@ -411,7 +424,7 @@ public class GTaskClient {
             throw new ActionFailureException("create tasklist: handing jsonobject failed");
         }
     }
-
+    //同步更新操作，使用jsonobject进行数据存储
     public void commitUpdate() throws NetworkFailureException {
         if (mUpdateArray != null) {
             try {
@@ -432,7 +445,7 @@ public class GTaskClient {
             }
         }
     }
-
+    //添加更新事项
     public void addUpdateNode(Node node) throws NetworkFailureException {
         if (node != null) {
             // too many update items may result in an error
@@ -446,7 +459,12 @@ public class GTaskClient {
             mUpdateArray.put(node.getUpdateAction(getActionId()));
         }
     }
-
+    /*
+     * 移动task,比如讲task移动到不同的task列表中去
+     * 通过getGid获取task所属列表的gid
+     * 通过JSONObject.put(String name, Object value)函数设置移动后的task的相关属性值，从而达到移动的目的
+     * 最后还是通过postRequest进行更新后的发送
+     */
     public void moveTask(Task task, TaskList preParent, TaskList curParent)
             throws NetworkFailureException {
         commitUpdate();
@@ -485,7 +503,11 @@ public class GTaskClient {
             throw new ActionFailureException("move task: handing jsonobject failed");
         }
     }
-
+    /*
+     * 删除操作节点
+     * 还是利用JSON
+     * 删除过后使用postRequest发送删除后的结果
+     */
     public void deleteNode(Node node) throws NetworkFailureException {
         commitUpdate();
         try {
@@ -508,7 +530,11 @@ public class GTaskClient {
             throw new ActionFailureException("delete node: handing jsonobject failed");
         }
     }
-
+    /*
+     * 获取任务列表
+     * 首先通过GetURI使用getResponseContent从网上获取数据
+     * 然后筛选出"_setup("到)}</script>的部分，并且从中获取GTASK_JSON_LISTS的内容返回
+     */
     public JSONArray getTaskLists() throws NetworkFailureException {
         if (!mLoggedin) {
             Log.e(TAG, "please login first");
@@ -546,7 +572,7 @@ public class GTaskClient {
             throw new ActionFailureException("get task lists: handing jasonobject failed");
         }
     }
-
+    //通过传入的TASKList的gid,从网络上获取相应属于这个任务列表的任务
     public JSONArray getTaskList(String listGid) throws NetworkFailureException {
         commitUpdate();
         try {
@@ -579,6 +605,7 @@ public class GTaskClient {
         return mAccount;
     }
 
+    //重置更新的内容
     public void resetUpdateArray() {
         mUpdateArray = null;
     }

src/Notes-master/app/src/main/java/net/micode/notes/gtask/remote/GTaskManager.java

@@ -88,15 +88,15 @@ public class GTaskManager {
     private HashMap<Long, String> mNidToGid;
 
     private GTaskManager() {
-        mSyncing = false;
-        mCancelled = false;
-        mGTaskListHashMap = new HashMap<String, TaskList>();
+        mSyncing = false;                                      //正在同步,flase代表未执行
+        mCancelled = false;                                    //全局标识，flase代表可以执行
+        mGTaskListHashMap = new HashMap<String, TaskList>();   //<>代表Java的泛型,就是创建一个用类型作为参数的类。
         mGTaskHashMap = new HashMap<String, Node>();
         mMetaHashMap = new HashMap<String, MetaData>();
         mMetaList = null;
         mLocalDeleteIdMap = new HashSet<Long>();
-        mGidToNid = new HashMap<String, Long>();
-        mNidToGid = new HashMap<Long, String>();
+        mGidToNid = new HashMap<String, Long>();    //GoogleID to NodeID??
+        mNidToGid = new HashMap<Long, String>();    //NodeID to GoogleID???通过hashmap散列表建立映射
     }
 
     public static synchronized GTaskManager getInstance() {
@@ -105,12 +105,12 @@ public class GTaskManager {
         }
         return mInstance;
     }
-
+    //指明该函数可能运行在多线程的环境下
     public synchronized void setActivityContext(Activity activity) {
         // used for getting authtoken
         mActivity = activity;
     }
-
+    //实现了本地同步操作和远端同步操作
     public int sync(Context context, GTaskASyncTask asyncTask) {
         if (mSyncing) {
             Log.d(TAG, "Sync is in progress");
@@ -167,7 +167,7 @@ public class GTaskManager {
 
         return mCancelled ? STATE_SYNC_CANCELLED : STATE_SUCCESS;
     }
-
+    //初始化GtaskList，获取Google上的JSONtasklist转为本地TaskList
     private void initGTaskList() throws NetworkFailureException {
         if (mCancelled)
             return;
@@ -246,7 +246,7 @@ public class GTaskManager {
             throw new ActionFailureException("initGTaskList: handing JSONObject failed");
         }
     }
-
+    //本地内容同步操作
     private void syncContent() throws NetworkFailureException {
         int syncType;
         Cursor c = null;
@@ -475,7 +475,7 @@ public class GTaskManager {
         if (!mCancelled)
             GTaskClient.getInstance().commitUpdate();
     }
-
+    //功能：syncType分类，addLocalNode，addRemoteNode，deleteNode，updateLocalNode，updateRemoteNode
     private void doContentSync(int syncType, Node node, Cursor c) throws NetworkFailureException {
         if (mCancelled) {
             return;
@@ -521,7 +521,7 @@ public class GTaskManager {
                 throw new ActionFailureException("unkown sync action type");
         }
     }
-
+    //本地增加Node
     private void addLocalNode(Node node) throws NetworkFailureException {
         if (mCancelled) {
             return;
@@ -595,7 +595,7 @@ public class GTaskManager {
         // update meta
         updateRemoteMeta(node.getGid(), sqlNote);
     }
-
+    //功能：update本地node
     private void updateLocalNode(Node node, Cursor c) throws NetworkFailureException {
         if (mCancelled) {
             return;
@@ -618,7 +618,7 @@ public class GTaskManager {
         // update meta info
         updateRemoteMeta(node.getGid(), sqlNote);
     }
-
+    //功能：远程增加Node
     private void addRemoteNode(Node node, Cursor c) throws NetworkFailureException {
         if (mCancelled) {
             return;
@@ -691,7 +691,7 @@ public class GTaskManager {
         mGidToNid.put(n.getGid(), sqlNote.getId());
         mNidToGid.put(sqlNote.getId(), n.getGid());
     }
-
+    //功能：更新远端的Node，包含meta更新(updateRemoteMeta)
     private void updateRemoteNode(Node node, Cursor c) throws NetworkFailureException {
         if (mCancelled) {
             return;
@@ -729,7 +729,7 @@ public class GTaskManager {
         sqlNote.resetLocalModified();
         sqlNote.commit(true);
     }
-
+    //功能：升级远程meta。  meta---元数据----计算机文件系统管理数据---管理数据的数据
     private void updateRemoteMeta(String gid, SqlNote sqlNote) throws NetworkFailureException {
         if (sqlNote != null && sqlNote.isNoteType()) {
             MetaData metaData = mMetaHashMap.get(gid);
@@ -745,7 +745,7 @@ public class GTaskManager {
             }
         }
     }
-
+    //功能：刷新本地，给sync的ID对应上最后更改过的对象
     private void refreshLocalSyncId() throws NetworkFailureException {
         if (mCancelled) {
             return;
@@ -789,7 +789,7 @@ public class GTaskManager {
             }
         }
     }
-
+    //功能：获取同步账号,mAccount.name
     public String getSyncAccount() {
         return GTaskClient.getInstance().getSyncAccount().name;
     }

src/Notes-master/app/src/main/java/net/micode/notes/gtask/remote/GTaskSyncService.java

@@ -22,7 +22,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
 import android.os.IBinder;
-
+//Service是在一段不定的时间运行在后台，不和用户交互的应用组件
 public class GTaskSyncService extends Service {
     public final static String ACTION_STRING_NAME = "sync_action_type";
 
@@ -41,7 +41,7 @@ public class GTaskSyncService extends Service {
     private static GTaskASyncTask mSyncTask = null;
 
     private static String mSyncProgress = "";
-
+    //启动一个同步工作
     private void startSync() {
         if (mSyncTask == null) {
             mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {
@@ -55,7 +55,7 @@ public class GTaskSyncService extends Service {
             mSyncTask.execute();
         }
     }
-
+    //取消同步
     private void cancelSync() {
         if (mSyncTask != null) {
             mSyncTask.cancelSync();
@@ -66,7 +66,7 @@ public class GTaskSyncService extends Service {
     public void onCreate() {
         mSyncTask = null;
     }
-
+    //service生命周期的组成部分，相当于重启service（比如在被暂停之后），而不是创建一个新的service
     @Override
     public int onStartCommand(Intent intent, int flags, int startId) {
         Bundle bundle = intent.getExtras();
@@ -85,7 +85,7 @@ public class GTaskSyncService extends Service {
         }
         return super.onStartCommand(intent, flags, startId);
     }
-
+    //在没有内存的情况下如果存在service则结束掉这的service
     @Override
     public void onLowMemory() {
         if (mSyncTask != null) {
@@ -96,7 +96,7 @@ public class GTaskSyncService extends Service {
     public IBinder onBind(Intent intent) {
         return null;
     }
-
+    //发送同步的相关通知
     public void sendBroadcast(String msg) {
         mSyncProgress = msg;
         Intent intent = new Intent(GTASK_SERVICE_BROADCAST_NAME);
@@ -117,7 +117,7 @@ public class GTaskSyncService extends Service {
         intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_CANCEL_SYNC);
         context.startService(intent);
     }
-
+    //判读是否在进行同步
     public static boolean isSyncing() {
         return mSyncTask != null;
     }

src/Notes-master/app/src/main/java/net/micode/notes/tool/BackupUtils.java

@@ -42,6 +42,9 @@ public class BackupUtils {
     private static BackupUtils sInstance;
 
     public static synchronized BackupUtils getInstance(Context context) {
+        //ynchronized 关键字，代表这个方法加锁,相当于不管哪一个线程（例如线程A）
+        //运行到这个方法时,都要检查有没有其它线程B（或者C、 D等）正在用这个方法(或者该类的其他同步方法)，有的话要等正在使用synchronized方法的线程B（或者C 、D）运行完这个方法后再运行此线程A,没有的话,锁定调用者,然后直接运行。
+        //它包括两种用法：synchronized 方法和 synchronized 块。
         if (sInstance == null) {
             sInstance = new BackupUtils(context);
         }
@@ -139,6 +142,7 @@ public class BackupUtils {
         /**
          * Export the folder identified by folder id to text
          */
+        //通过查询parent id是文件夹id的note来选出制定ID文件夹下的Note
         private void exportFolderToText(String folderId, PrintStream ps) {
             // Query notes belong to this folder
             Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
@@ -218,6 +222,7 @@ public class BackupUtils {
         /**
          * Note will be exported as text which is user readable
          */
+        //注释将导出为用户可读的文本
         public int exportToText() {
             if (!externalStorageAvailable()) {
                 Log.d(TAG, "Media was not mounted");
@@ -229,7 +234,7 @@ public class BackupUtils {
                 Log.e(TAG, "get print stream error");
                 return STATE_SYSTEM_ERROR;
             }
-            // First export folder and its notes
+            // First export folder and its notes导出文件夹
             Cursor folderCursor = mContext.getContentResolver().query(
                     Notes.CONTENT_NOTE_URI,
                     NOTE_PROJECTION,
@@ -258,6 +263,7 @@ public class BackupUtils {
             }
 
             // Export notes in root's folder
+            // 将根目录里的便签导出（由于不属于任何文件夹，因此无法通过文件夹导出来实现这一部分便签的导出）
             Cursor noteCursor = mContext.getContentResolver().query(
                     Notes.CONTENT_NOTE_URI,
                     NOTE_PROJECTION,
@@ -314,16 +320,16 @@ public class BackupUtils {
      */
     private static File generateFileMountedOnSDcard(Context context, int filePathResId, int fileNameFormatResId) {
         StringBuilder sb = new StringBuilder();
-        sb.append(Environment.getExternalStorageDirectory());
-        sb.append(context.getString(filePathResId));
-        File filedir = new File(sb.toString());
+        sb.append(Environment.getExternalStorageDirectory());  //外部（SD卡）的存储路径
+        sb.append(context.getString(filePathResId));    //文件的存储路径
+        File filedir = new File(sb.toString());        //filedir应该就是用来存储路径信息
         sb.append(context.getString(
                 fileNameFormatResId,
                 DateFormat.format(context.getString(R.string.format_date_ymd),
                         System.currentTimeMillis())));
         File file = new File(sb.toString());
 
-        try {
+        try {//如果这些文件不存在，则新建
             if (!filedir.exists()) {
                 filedir.mkdir();
             }
@@ -337,6 +343,7 @@ public class BackupUtils {
             e.printStackTrace();
         }
 
+        // try catch 异常处理
         return null;
     }
 }

src/Notes-master/app/src/main/java/net/micode/notes/tool/DataUtils.java

@@ -37,7 +37,7 @@ import java.util.HashSet;
 
 public class DataUtils {
     public static final String TAG = "DataUtils";
-    public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {
+    public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {//直接删除多个笔记
         if (ids == null) {
             Log.d(TAG, "the ids is null");
             return true;
@@ -46,7 +46,7 @@ public class DataUtils {
             Log.d(TAG, "no id is in the hashset");
             return true;
         }
-
+        //提供一个任务列表
         ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
         for (long id : ids) {
             if(id == Notes.ID_ROOT_FOLDER) {
@@ -54,11 +54,12 @@ public class DataUtils {
                 continue;
             }
             ContentProviderOperation.Builder builder = ContentProviderOperation
-                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));//用newDelete实现删除功能
             operationList.add(builder.build());
         }
-        try {
+        try {//主机名（或叫Authority）用于唯一标识这个ContentProvider，外部调用者可以根据这个标识来找到它。
             ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            //数据库事务，数据库事务是由一组数据库操作序列组成，事务作为一个整体被执行
             if (results == null || results.length == 0 || results[0] == null) {
                 Log.d(TAG, "delete notes failed, ids:" + ids.toString());
                 return false;
@@ -114,7 +115,7 @@ public class DataUtils {
     /**
      * Get the all folder count except system folders {@link Notes#TYPE_SYSTEM}}
      */
-    public static int getUserFolderCount(ContentResolver resolver) {
+    public static int getUserFolderCount(ContentResolver resolver) {//通过withAppendedId方法，为该Uri加上ID
         Cursor cursor =resolver.query(Notes.CONTENT_NOTE_URI,
                 new String[] { "COUNT(*)" },
                 NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>?",
@@ -145,7 +146,7 @@ public class DataUtils {
 
         boolean exist = false;
         if (cursor != null) {
-            if (cursor.getCount() > 0) {
+            if (cursor.getCount() > 0) {//用getcount函数判断cursor是否为空
                 exist = true;
             }
             cursor.close();
@@ -187,6 +188,7 @@ public class DataUtils {
                 " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER +
                 " AND " + NoteColumns.SNIPPET + "=?",
                 new String[] { name }, null);
+        //通过名字查询文件是否存在
         boolean exist = false;
         if(cursor != null) {
             if(cursor.getCount() > 0) {
@@ -250,7 +252,7 @@ public class DataUtils {
                 + CallNote.PHONE_NUMBER + ",?)",
                 new String [] { String.valueOf(callDate), CallNote.CONTENT_ITEM_TYPE, phoneNumber },
                 null);
-
+        //通过数据库操作，查询条件是（callDate和phoneNumber匹配传入参数的值）
         if (cursor != null) {
             if (cursor.moveToFirst()) {
                 try {

src/Notes-master/app/src/main/java/net/micode/notes/tool/GTaskStringUtils.java

@@ -15,7 +15,7 @@
  */
 
 package net.micode.notes.tool;
-
+//为jsonObject提供Key，把这些定义全部写到一个类里，方便查看管理
 public class GTaskStringUtils {
 
     public final static String GTASK_JSON_ACTION_ID = "action_id";

src/Notes-master/app/src/main/java/net/micode/notes/tool/ResourceParser.java

@@ -21,7 +21,7 @@ import android.preference.PreferenceManager;
 
 import net.micode.notes.R;
 import net.micode.notes.ui.NotesPreferenceActivity;
-
+//获取资源并且在程序中使用，比如颜色图片等
 public class ResourceParser {
 
     public static final int YELLOW           = 0;