Merge pull request '注释代码' (#4) from develop into master

doc/韩嘉辉注释的代码/ActionFailureException.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.exception;
+
+public class ActionFailureException extends RuntimeException {
+    private static final long serialVersionUID = 4425249765923293627L;
+    /*
+     * serialVersionUID相当于java类的身份证。主要用于版本控制。
+     * serialVersionUID作用是序列化时保持版本的兼容性，即在版本升级时反序列化仍保持对象的唯一性。
+     * Made By Cuican
+     */
+
+    public ActionFailureException() {
+        super();
+    }
+    /*
+     * 在JAVA类中使用super来引用父类的成分，用this来引用当前对象.
+     * 如果一个类从另外一个类继承，我们new这个子类的实例对象的时候，这个子类对象里面会有一个父类对象。
+     * 怎么去引用里面的父类对象呢？使用super来引用
+     * 也就是说，此处super()以及super (paramString)可认为是Exception ()和Exception (paramString)
+     * Made By Cuican
+     */
+    public ActionFailureException(String paramString) {
+        super(paramString);
+    }
+
+    public ActionFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable);
+    }
+}

doc/韩嘉辉注释的代码/Contact.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.provider.ContactsContract.CommonDataKinds.Phone;
+import android.provider.ContactsContract.Data;
+import android.telephony.PhoneNumberUtils;
+import android.util.Log;
+
+import java.util.HashMap;
+
+public class Contact {
+//    创建contact类，调用的哈希类方法，实现对于联系人信息的储存与应用
+    private static HashMap<String, String> sContactCache;
+//    就是把Map里面的元素（包括类型）写入缓存
+    private static final String TAG = "Contact";
+//    java自定义标签TAG指向Contact
+
+    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
+
+    + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
+    + " AND " + Data.RAW_CONTACT_ID + " IN "
+            + "(SELECT raw_contact_id "
+            + " FROM phone_lookup"
+            + " WHERE min_match = '+')";
+//    CALLER_ID_SELECTION：根据信息筛选联系人，包含电话号码，信息类型，电话类型，联系人ID
+    public static String getContact(Context context, String phoneNumber) {
+//        功能：获取联系人
+//        实现过程：首先先在sContactCache这个HashMap中去找，如果没有找到就先新建立一个hashmap数据结构用来缓存，然后将CALL_ID_SELECTED中选择出电话号，然后去数据库里面查询，如果找到对应的联系人就把他加入到hashmap中并且返回联系人的名字，如果在数据库中还没有找到就返回null；如果直接在sContactCache这个HashMap中找到，就直接返回联系人名字对应的电话号码
+//        参数：一个是Context类型的变量，可以实现时活动，服务等，是调用这个方法的组件，另一个是一个string类型变量，表示输入的电话号码
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+//            对联系人缓存表进行初始化
+        }
+//        如果联系人缓存为空，重新从HashMap载入，包括数据类型
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+        // 查找HashMap中是否已有该phoneNumber信息 有的话直接获取并返回
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        //    修改原先数据库语句Caller_ID_SELECTION，用函数形参phonenumber的后七位电话号码代替"+"，因为int min_match=7，所以是七位
+        Cursor cursor = context.getContentResolver().query(
+                //        从数据库中读取数据。cursor类是对数据库的操作，获取整行的数据.Ressolver是对联系人内容的读取，其中provider提供了联系人数据
+                Data.CONTENT_URI,
+//                Contacts.CONTENT_URI就是提供联系人的内容的地址
+                new String [] { Phone.DISPLAY_NAME },
+//                这个参数告诉查询要返回的列（Column），Contacts Provider提供了联系人的ID和联系人的NAME等内容，在这里，我们只需要NAME，所以提供这个参数DISPLAY_NAME
+                selection,
+//                selection，设置条件，相当于SQL语句中的where
+                new String[] { phoneNumber },
+//                配合上一个参数使用，若上一个参数里有‘？’则替换掉‘？’符号，但是在这里，由于上一个参数没有设置，所以在这里就是依据phoneNumber作为参数
+                null);
+
+        if (cursor != null && cursor.moveToFirst()) {
+//            若数据库存在，则游标移动到游标所表示的信息元组的第一行开始
+            try {
+//                try-catch-finally ：先执行try块，有异常抛出，执行catch块，再执行finally块；没有异常抛出，直接执行finally块
+                String name = cursor.getString(0);
+//                返回cursor类型获取到的数据库：第x行的第0列的值。上文cursor已经由数据库根据phoneNumber查找到某一行的信息元组，再从这个元组中提取某一列的值。
+                sContactCache.put(phoneNumber, name);
+//                在哈希表中放入（键，值），也就是由电话号码索引的名字
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+//                如果查询时出错，就将Cursor get string error打印到错误日志，然后返回null
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+//                finally块通常用于try内，无论是否发生异常都会执行finally模块，因此多使用 finally 代码块执行关闭连接、关闭文件和释放线程的的操作。
+                cursor.close();
+//                使用游标过后释放，若不自己写释放代码，则系统会自动释放，但这里是处于安全编程的角度而写下释放资源。
+            }
+        } else {
+//            若数据库中找不到与phoneNumber匹配的联系人名，则提示下列信息
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}

doc/韩嘉辉注释的代码/GTaskASyncTask.java

@@ -0,0 +1,140 @@
+
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.remote;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.os.AsyncTask;
+
+import net.micode.notes.R;
+import net.micode.notes.ui.NotesListActivity;
+import net.micode.notes.ui.NotesPreferenceActivity;
+
+
+public class GTaskASyncTask extends AsyncTask<Void, String, Integer> {
+    /*异步操作类，实现GTask的异步操作过程
+     * 主要方法：
+     * private void showNotification(int tickerId, String content) 向用户提示当前同步的状态，是一个用于交互的方法
+     * protected Integer doInBackground(Void... unused) 此方法在后台线程执行，完成任务的主要工作，通常需要较长的时间
+     * protected void onProgressUpdate(String... progress)  可以使用进度条增加用户体验度。 此方法在主线程执行，用于显示任务执行的进度。
+     * protected void onPostExecute(Integer result)  相当于Handler 处理UI的方式，在这里面可以使用在doInBackground 得到的结果处理操作UI
+     */
+    private static int GTASK_SYNC_NOTIFICATION_ID = 5234235;
+//    定义一个变量用来存储往通知栏发送信息的ID，作为来自该应用的信息的标志
+    public interface OnCompleteListener {
+//    提供了一个对OnCompleteListener的接口，目的是在便签同步完成时发送消息
+        void onComplete();
+    }
+
+    private Context mContext;
+
+    private NotificationManager mNotifiManager;
+//    通知管理器，整个系统只有一个，通过getSystemService()函数来获得，它负责管理发送通知、清除通知等一系列的对通知的管理工作。
+    private GTaskManager mTaskManager;
+
+    private OnCompleteListener mOnCompleteListener;
+//    实例化是否完成的监听器
+    public GTaskASyncTask(Context context, OnCompleteListener listener) {
+//        功能：GTaskASyncTask类的构造函数
+//        实现：对GTaskASyncTask类的四个成员变量赋值
+//        参数：context类 通过它可以访问application的资源和相关的类
+        mContext = context;
+        mOnCompleteListener = listener;
+        mNotifiManager = (NotificationManager) mContext
+                .getSystemService(Context.NOTIFICATION_SERVICE);
+        mTaskManager = GTaskManager.getInstance();
+    }
+
+    public void cancelSync() {
+//        调用mTaskManager中的异步取消函数
+        mTaskManager.cancelSync();
+    }
+
+    public void publishProgess(String message) {
+//        publishProgress函数的作用是循环播放文字广告，这里引用为显示定义的字符串message
+        publishProgress(new String[] {
+            message
+        });
+    }
+
+    private void showNotification(int tickerId, String content) {
+//        显示通知消息，在这里主要用于向用户通知同步的进程
+        PendingIntent pendingIntent;
+        if (tickerId != R.string.ticker_success) {
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesPreferenceActivity.class), 0);
+
+        } else {
+            pendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(mContext,
+                    NotesListActivity.class), 0);
+        }
+
+
+        Notification.Builder builder = new Notification.Builder(mContext)
+                .setAutoCancel(true)
+                .setContentTitle(mContext.getString(R.string.app_name))
+                .setContentText(content)
+                .setContentIntent(pendingIntent)
+                .setWhen(System.currentTimeMillis())
+                .setOngoing(true);
+        Notification notification=builder.getNotification();
+        mNotifiManager.notify(GTASK_SYNC_NOTIFICATION_ID, notification);
+    }
+
+    @Override
+    protected Integer doInBackground(Void... unused) {
+        publishProgess(mContext.getString(R.string.sync_progress_login, NotesPreferenceActivity
+                .getSyncAccountName(mContext)));
+        return mTaskManager.sync(mContext, this);
+    }
+
+    @Override
+    protected void onProgressUpdate(String... progress) {
+        showNotification(R.string.ticker_syncing, progress[0]);
+        if (mContext instanceof GTaskSyncService) {
+            ((GTaskSyncService) mContext).sendBroadcast(progress[0]);
+        }
+    }
+
+    @Override
+    protected void onPostExecute(Integer result) {
+        if (result == GTaskManager.STATE_SUCCESS) {
+            showNotification(R.string.ticker_success, mContext.getString(
+                    R.string.success_sync_account, mTaskManager.getSyncAccount()));
+            NotesPreferenceActivity.setLastSyncTime(mContext, System.currentTimeMillis());
+        } else if (result == GTaskManager.STATE_NETWORK_ERROR) {
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_network));
+        } else if (result == GTaskManager.STATE_INTERNAL_ERROR) {
+            showNotification(R.string.ticker_fail, mContext.getString(R.string.error_sync_internal));
+        } else if (result == GTaskManager.STATE_SYNC_CANCELLED) {
+            showNotification(R.string.ticker_cancel, mContext
+                    .getString(R.string.error_sync_cancelled));
+        }
+        if (mOnCompleteListener != null) {
+            new Thread(new Runnable() {
+
+                public void run() {
+                    mOnCompleteListener.onComplete();
+                }
+            }).start();
+        }
+    }
+}

doc/韩嘉辉注释的代码/MetaData.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//1. 关于同步任务的元数据
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+
+public class MetaData extends Task {
+    /*
+     * 功能描述：得到类的简写名称存入字符串TAG中
+     * 实现过程：调用getSimpleName ()函数
+     */
+    private final static String TAG = MetaData.class.getSimpleName();
+    private String mRelatedGid = null;
+    /*
+     * 功能描述：设置数据，即生成元数据库
+     * 实现过程：调用JSONObject库函数put ()，Task类中的setNotes ()和setName ()函数
+     * 参数注解：
+     */
+    public void setMeta(String gid, JSONObject metaInfo)
+    {
+        //对函数块进行注释
+        try {
+            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
+            /*
+             * 将这对键值放入metaInfo这个jsonobject对象中
+             */
+        } catch (JSONException e) {
+            Log.e(TAG, "failed to put related gid");
+            /*
+             * 输出错误信息
+             */
+        }
+        setNotes(metaInfo.toString());
+        setName(GTaskStringUtils.META_NOTE_NAME);
+    }
+    /*
+     * 功能描述：获取相关联的Gid
+     */
+    public String getRelatedGid() {
+        return mRelatedGid;
+    }
+    /*
+     * 功能描述：判断当前数据是否为空，若为空则返回真即值得保存
+     * Made By CuiCan
+     */
+    @Override
+    public boolean isWorthSaving() {
+        return getNotes() != null;
+    }
+    /*
+     * 功能描述：使用远程json数据对象设置元数据内容
+     * 实现过程：调用父类Task中的setContentByRemoteJSON ()函数，并
+     * 参数注解：
+     */
+    @Override
+    public void setContentByRemoteJSON(JSONObject js) {
+        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");
+                /*
+                 * 输出警告信息
+                 */
+                mRelatedGid = null;
+            }
+        }
+    }
+    /*
+     * 功能描述：使用本地json数据对象设置元数据内容，一般不会用到，若用到，则抛出异常
+     * Made By CuiCan
+     */
+    @Override
+    public void setContentByLocalJSON(JSONObject js) {
+        // this function should not be called
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+        /*
+         * 传递非法参数异常
+         */
+    }
+    /*
+     * 功能描述：从元数据内容中获取本地json对象，一般不会用到，若用到，则抛出异常
+     * Made By CuiCan
+     */
+    @Override
+    public JSONObject getLocalJSONFromContent() {
+        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
+        /*
+         * 传递非法参数异常
+         * Made By Cui Can
+         */
+    }
+    /*
+     * 功能描述：获取同步动作状态，一般不会用到，若用到，则抛出异常
+     * Made By CuiCan
+     */
+    @Override
+    public int getSyncAction(Cursor c) {
+        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
+        /*
+         * 传递非法参数异常
+         * Made By Cui Can
+         */
+    }
+
+}
+

doc/韩嘉辉注释的代码/NetworkFailureException.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.exception;
+
+
+public class NetworkFailureException extends Exception {
+    private static final long serialVersionUID = 2107610287180234136L;
+    /*
+     * serialVersionUID相当于java类的身份证。主要用于版本控制。
+     * serialVersionUID作用是序列化时保持版本的兼容性，即在版本升级时反序列化仍保持对象的唯一性。
+     * Made By Cuican
+     */
+
+    public NetworkFailureException() {
+        super();
+    }
+
+    /*
+     * 在JAVA类中使用super来引用父类的成分，用this来引用当前对象.
+     * 如果一个类从另外一个类继承，我们new这个子类的实例对象的时候，这个子类对象里面会有一个父类对象。
+     * 怎么去引用里面的父类对象呢？使用super来引用
+     * 也就是说，此处super()以及super (paramString)可认为是Exception ()和Exception (paramString)
+     * Made By Cuican
+     */
+    public NetworkFailureException(String paramString) {
+        super(paramString);
+    }
+
+    public NetworkFailureException(String paramString, Throwable paramThrowable) {
+        super(paramString, paramThrowable);
+    }
+}

doc/韩嘉辉注释的代码/Node.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+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;// 本地和云端都无可更新内容（即本地和云端内容一致）
+
+    public static final int SYNC_ACTION_ADD_REMOTE = 1;// 需要在远程云端增加内容
+
+    public static final int SYNC_ACTION_ADD_LOCAL = 2;// 需要在本地增加内容
+
+    public static final int SYNC_ACTION_DEL_REMOTE = 3;// 需要在远程云端删除内容
+
+    public static final int SYNC_ACTION_DEL_LOCAL = 4;// 需要在本地删除内容
+
+    public static final int SYNC_ACTION_UPDATE_REMOTE = 5;// 需要将本地内容更新到远程云端
+
+    public static final int SYNC_ACTION_UPDATE_LOCAL = 6;// 需要将远程云端内容更新到本地
+
+    public static final int SYNC_ACTION_UPDATE_CONFLICT = 7;// 同步出现冲突
+
+    public static final int SYNC_ACTION_ERROR = 8;// 同步出现错误
+
+    private String mGid;
+
+    private String mName;
+
+    private long mLastModified;//记录最后一次修改时间
+
+    private boolean mDeleted;//表征是否被删除
+
+    public Node() {
+        mGid = null;
+        mName = "";
+        mLastModified = 0;
+        mDeleted = false;
+    }
+
+    public abstract JSONObject getCreateAction(int actionId);
+
+    public abstract JSONObject getUpdateAction(int actionId);
+
+    public abstract void setContentByRemoteJSON(JSONObject js);
+
+    public abstract void setContentByLocalJSON(JSONObject js);
+
+    public abstract JSONObject getLocalJSONFromContent();
+
+    public abstract int getSyncAction(Cursor c);
+
+    public void setGid(String gid) {
+        this.mGid = gid;
+    }
+
+    public void setName(String name) {
+        this.mName = name;
+    }
+
+    public void setLastModified(long lastModified) {
+        this.mLastModified = lastModified;
+    }
+
+    public void setDeleted(boolean deleted) {
+        this.mDeleted = deleted;
+    }
+
+    public String getGid() {
+        return this.mGid;
+    }
+
+    public String getName() {
+        return this.mName;
+    }
+
+    public long getLastModified() {
+        return this.mLastModified;
+    }
+
+    public boolean getDeleted() {
+        return this.mDeleted;
+    }
+
+}
+

doc/韩嘉辉注释的代码/Notes.java

@@ -0,0 +1,302 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//本文件实现便签的数据库,实现了对便签的相关属性包括：Anthority, Tag，以及数据，联系人的信息进行保存管理，实现了对若干属性的定义，并定义了DataColumns，DataColumns接口，可用于其余类的实现，在便签管理中实现TextNote,CallNote两个类，用于对便签内容的保存。
+package net.micode.notes.data;
+
+import android.net.Uri;
+//uri是统一资源标志符（Uniform Resource Identifier），而在这个类中定义了各种Uri常量，以便在其他的类中调用。Uri用处很多，涉及到安卓权限，比如通过Uri可以： 直接拨打电话、调出拨打电话界面、调WEB浏览器、卸载、安装、播放、调用发邮件、直接发邮件等系统功能
+public class Notes {
+//    Notes类，定义一些基本标识符。该类不对标识符进行任何操作，仅仅只是定义，供其他类调用
+    public static final String AUTHORITY = "micode_notes";
+//    定义了一个权限名，这里是为了符合Uri的格式而定义的。
+    public static final String TAG = "Notes";
+//    设置标签，表示APP的名称是Notes
+    public static final int TYPE_NOTE     = 0;
+//    以下三个常量对NoteColumns.TYPE的值进行设置时会用到
+    public static final int TYPE_FOLDER   = 1;
+    public static final int TYPE_SYSTEM   = 2;
+//    下列ID是系统文件的标识{1.根目录（默认文件夹）2.临时文件夹 3.通话记录}
+    /**
+     * Following IDs are system folders' identifiers
+     * {@link Notes#ID_ROOT_FOLDER } is default folder
+     * {@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;
+//    根文件夹ID=0
+    public static final int ID_TEMPARAY_FOLDER = -1;
+//    临时文件夹ID=-1
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+//    通话记录文件夹id=-2
+    public static final int ID_TRASH_FOLER = -3;
+//    垃圾文件夹id=-3
+
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
+//    . 定义ID：通知日期，背景颜色，小部件ID，小部件类型，文件夹ID，来电类型
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
+    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";
+
+    public static final int TYPE_WIDGET_INVALIDE      = -1;
+    public static final int TYPE_WIDGET_2X            = 0;
+    public static final int TYPE_WIDGET_4X            = 1;
+
+    public static class DataConstants {
+//        建立DataContants类：存放textnotes和callnotes地址
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
+//        定义变量NOTE，用来识别text_note的存放地址
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
+//        定义变量CALL_NOTE，用来标志call_note的存放地址
+    }
+
+    /**
+     * Uri to query all notes and folders
+     */
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+//    定义了Uri常量，便于以后调用系统查询功能（查询所有note和文件夹）
+    /**
+     * Uri to query data
+//     * 查询所有笔记和文件夹的uri
+     */
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+//    调用AUTHORITY的方法，操作data数据
+    public interface NoteColumns {
+//    定义一个接口类，这里是由若干属性（string）组织成的集合，在之后的NotesDatabaseHelper数据库创建、查询、修改中使用，这里储存的就是关于便签属性的信息，比如创建时间、修改时间、提醒时间等信息。
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+//    这些常量主要是定义便签的属性的。
+
+        /**
+         * The parent's id for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String PARENT_ID = "parent_id";
+//    父节点id的字符串
+
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+//    创建note和文件夹时的数据，如创建时间等
+
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+//    最近更新的时间等数据
+
+
+        /**
+         * Alert date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ALERTED_DATE = "alert_date";
+//    提醒时间等数据
+        /**
+         * Folder's name or text content of note
+         * <P> Type: TEXT </P>
+         */
+        public static final String SNIPPET = "snippet";
+// 文件夹的名称或便签的内容等数据
+        /**
+         * Note's widget id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String WIDGET_ID = "widget_id";
+//    语句：小部件的ID
+        /**
+         * Note's widget type
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String WIDGET_TYPE = "widget_type";
+//    便签背景颜色备注id
+        /**
+         * Note's background color's id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String BG_COLOR_ID = "bg_color_id";
+//    便签背景颜色的ID
+        /**
+         * For text note, it doesn't has attachment, for multi-media
+         * note, it has at least one attachment
+         * <P> Type: INTEGER </P>
+         */
+        public static final String HAS_ATTACHMENT = "has_attachment";
+//    标识是否有附件
+        /**
+         * Folder's count of notes
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String NOTES_COUNT = "notes_count";
+//    通过对相应标签字符串的定义，方便以后准确的引用
+        /**
+         * The file type: folder or note
+         * <P> Type: INTEGER </P>
+         */
+        public static final String TYPE = "type";
+//    类型：是便签还是文件夹
+        /**
+         * The last sync id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String SYNC_ID = "sync_id";
+//    最后一次同步的ID
+        /**
+         * Sign to indicate local modified or not
+         * <P> Type: INTEGER </P>
+         */
+        public static final String LOCAL_MODIFIED = "local_modified";
+//    表示是否修改本地的信号
+        /**
+         * Original parent id before moving into temporary folder
+         * <P> Type : INTEGER </P>
+         */
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";
+//    移动到临时文件夹之前的父节点的ID
+        /**
+         * The gtask id
+         * <P> Type : TEXT </P>
+         */
+        public static final String GTASK_ID = "gtask_id";
+//    后台任务的ID
+        /**
+         * The version code
+         * <P> Type : INTEGER (long) </P>
+         */
+        public static final String VERSION = "version";
+    }
+//    版本代号
+    public interface DataColumns {
+//    定义了接口类，在数据库的创建、查询中需要DataColumns的所有信息，主要存储便签数据的信息
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+//    主要是定义存储便签内容数据的
+        /**
+         * The MIME type of the item represented by this row.
+         * <P> Type: Text </P>
+         */
+        public static final String MIME_TYPE = "mime_type";
+//    这一行表示的项目的MIME类型。MIME是设定某种扩展名的文件用一种应用程序来打开的方式类型，当该扩展名文件被访问的时候，浏览器会自动使用指定应用程序来打开
+        /**
+         * The reference id to note that this data belongs to
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String NOTE_ID = "note_id";
+//    标签id
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+//    note或folder的创建时间
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+//    标记最后一次修改日期
+        /**
+         * Data's content
+         * <P> Type: TEXT </P>
+         */
+        public static final String CONTENT = "content";
+//    数据包含的内容
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
+        public static final String DATA1 = "data1";
+//    继承于DataColumns的一个类，用来组织文本内容的结构
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
+        public static final String DATA2 = "data2";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA3 = "data3";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA4 = "data4";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA5 = "data5";
+    }
+
+    public static final class TextNote implements DataColumns {
+//        文本数据（TextNote）通过关键字implements来实现接口，继承了DataColumns的所有定义常量
+        /**
+         * Mode to indicate the text in check list mode or not
+         * <P> Type: Integer 1:check list mode 0: normal mode </P>
+         */
+        public static final String MODE = DATA1;
+
+        public static final int MODE_CHECK_LIST = 1;
+//        便签模式 列表模式和文字模式
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";
+//        修改CONTENT_TYPE属性，即内容类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
+//        内容项目类型
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
+    }
+//    访问该content_provider的URI，parse方法返回的是一个URI类型。通过这个uri可以访问一个网络上或者本地上的资源
+    public static final class CallNote implements DataColumns {
+//    通话数据（CallNote）继承了接口类，而后进行了格式适配
+        /**
+         * Call date for this record
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CALL_DATE = DATA1;
+//    在DATA1中存放的是通话时间信息
+        /**
+         * Phone number for this record
+         * <P> Type: TEXT </P>
+         */
+        public static final String PHONE_NUMBER = DATA3;
+//    在DATA3中放的是通话号码信息
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";
+//    定义内容类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
+    }
+}

doc/韩嘉辉注释的代码/NotesDatabaseHelper.java

@@ -0,0 +1,393 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//该模块主要是用于存储Notes的数据，以及根据数据更改Notes结构体的变量
+package net.micode.notes.data;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.util.Log;
+
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+
+
+public class NotesDatabaseHelper extends SQLiteOpenHelper {
+//    创建SQLiteOpenHelper帮助类，实现创建和升级数据库的逻辑为了创建表和索引，需要调用 SQLiteDatabase 的 execSQL() 方法来执行 DDL 语句。如果没有异常，这个方法没有返回值。
+    private static final String DB_NAME = "note.db";
+//    定义数据库的名称为“note.db”
+    private static final int DB_VERSION = 4;
+//    定义数据库版本号为4
+    public interface TABLE {
+//    接口，分成note和data，在后面的程序里分别使用过
+        public static final String NOTE = "note";
+//    note和data都是数据库包含的信息类，所以自然有两个创建语句分别创建note和data的sql语句
+        public static final String DATA = "data";
+    }
+
+    private static final String TAG = "NotesDatabaseHelper";
+//    便签数据库的标签
+    private static NotesDatabaseHelper mInstance;
+//    创建类NotesDatabaseHelper的对象——mInstance
+    private static final String CREATE_NOTE_TABLE_SQL =
+//        当创建一个新的便签，就产生了各类关于便签的信息，比如ID，父便签ID，背景颜色，创建日期等，我们需要把这些信息放入数据库，这就是数据库的表头。我们在下面定义的涉及操作的字符串，全都是为了在之后执行db.execSQL("字符串")。
+        "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," +
+            NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +
+            NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +
+            NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
+            NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
+        ")";
+
+    private static final String CREATE_DATA_TABLE_SQL =
+//            大体同上，这里储存的是便签内容的信息，用这些信息作为数据库对便签内容存储的表头
+        "CREATE TABLE " + TABLE.DATA + "(" +
+            DataColumns.ID + " INTEGER PRIMARY KEY," +
+            DataColumns.MIME_TYPE + " TEXT NOT NULL," +
+            DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+            DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA1 + " INTEGER," +
+            DataColumns.DATA2 + " INTEGER," +
+            DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
+            DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
+        ")";
+
+    private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
+//            将便签的ID作为数据库的ID
+        "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
+     */
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+//            增加文件夹便签数量，当移动一个便签进入该文件夹后，以后在db.execSQL(字符串)中用到，启动自定义的数据库update触发器，有相关的一系列数据库操作。
+        "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
+     */
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+//            同上，从文件夹移除便签，文件夹便签数量减1，以后在db.execSQL(字符串)中用到，启动自定义的数据库updata触发器，附带相关的一系列操作
+        "CREATE TRIGGER decrease_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 + "=old." + NoteColumns.PARENT_ID +
+        "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
+        " END";
+
+    /**
+     * Increase folder's note count when insert new note to the folder
+     */
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
+//            文件夹中创建新便签，文件夹便签数量+1，启动自定义的数据库insert触发器，附带相关的一系列操作
+        "CREATE TRIGGER increase_folder_count_on_insert " +
+        " AFTER INSERT 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 delete note from the folder
+     */
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
+//            文件夹中删除便签，文件夹便签数量-1
+        "CREATE TRIGGER decrease_folder_count_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN " +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+        "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+        "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
+        " END";
+
+    /**
+     * Update note's content when insert data with type {@link DataConstants#NOTE}
+     */
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
+//            便签数据更新时，启动数据库insert触发器
+        "CREATE TRIGGER update_note_content_on_insert " +
+        " AFTER INSERT ON " + TABLE.DATA +
+        " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+        "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    /**
+     * Update note's content when data with {@link DataConstants#NOTE} type has changed
+     */
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
+//            便签数据更新时，启动数据库update触发器
+        "CREATE TRIGGER update_note_content_on_update " +
+        " AFTER UPDATE ON " + TABLE.DATA +
+        " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+        "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    /**
+     * Update note's content when data with {@link DataConstants#NOTE} type has deleted
+     */
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
+//            便签数据更新时，启动数据库delete触发器
+        "CREATE TRIGGER update_note_content_on_delete " +
+        " AFTER delete ON " + TABLE.DATA +
+        " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.SNIPPET + "=''" +
+        "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
+        " END";
+
+    /**
+     * Delete datas belong to note which has been deleted
+     */
+    private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
+//            删除便签数据，启动自定义的数据库delete触发器，有相关的一系列数据库操作。
+        "CREATE TRIGGER delete_data_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN" +
+        "  DELETE FROM " + TABLE.DATA +
+        "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    /**
+     * Delete notes belong to folder which has been deleted
+     */
+    private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
+//            文件夹删除便签，启动自定义的数据库delete触发器，有相关的一系列数据库操作。
+        "CREATE TRIGGER folder_delete_notes_on_delete " +
+        " AFTER DELETE ON " + TABLE.NOTE +
+        " BEGIN" +
+        "  DELETE FROM " + TABLE.NOTE +
+        "   WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    /**
+     * Move notes belong to folder which has been moved to trash folder
+     */
+    private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
+//            垃圾文件夹中便签还原，启动自定义的数据库trash触发器，有相关的一系列数据库操作。
+        "CREATE TRIGGER folder_move_notes_on_trash " +
+        " AFTER UPDATE ON " + TABLE.NOTE +
+        " WHEN new." + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+        " BEGIN" +
+        "  UPDATE " + TABLE.NOTE +
+        "   SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+        "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+        " END";
+
+    public NotesDatabaseHelper(Context context) {
+        super(context, DB_NAME, null, DB_VERSION);
+    }
+//    SQL的触发器是一个能由系统自动执行对数据库修改的语句，由文件的增加事件触发。
+    public void createNoteTable(SQLiteDatabase db) {
+//        create方法是数据库第一次创建的时候会被调用，调用了下文定义的私有函数
+        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        reCreateNoteTableTriggers(db);
+        createSystemFolder(db);
+        Log.d(TAG, "note table has been created");
+    }
+
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+//        重构原有的触发器，改成自己写的触发器，防止冲突
+        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);
+    }
+
+    private void createSystemFolder(SQLiteDatabase db) {
+        ContentValues values = new ContentValues();
+//        把系统文件夹：1.通话记录文件夹、2.根文件夹 3.垃圾文件夹 都创建出来
+        /**
+         * call record foler for call notes
+         */
+        values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        /**
+         * root folder which is default folder
+         */
+        values.clear();
+//        临时文件夹的修改操作
+        values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        /**
+         * temporary folder which is used for moving note
+         */
+        values.clear();
+//        创建垃圾文件夹的操作
+        values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+
+        /**
+         * create trash folder
+         */
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
+
+    public void createDataTable(SQLiteDatabase db) {
+//        创建数据库的data表单
+        db.execSQL(CREATE_DATA_TABLE_SQL);
+        reCreateDataTableTriggers(db);
+        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
+        Log.d(TAG, "data table has been created");
+    }
+
+    private void reCreateDataTableTriggers(SQLiteDatabase db) {
+//        重构数据库的data表单的触发器，防止定义冲突
+        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(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);
+    }
+
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+//        new和getInstance同为产生对象但是有区别：
+//  * 大部分类(非抽象类/接口/屏蔽了constructor的类)都可以用new，new就是通过生产一个新的实例对象，或者在栈上声明一个对象 ，每部分的调用的都是一个新的对象。
+//  * getInstance是少部分类才有的一个方法，各自的实现也不同。
+//  * getInstance在单例模式(保证一个类仅有一个实例，并提供一个访问它的全局访问点)的类中常见，用来生成唯一的实例，getInstance往往是static的
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+//        在对象生命周期开始的时候，onCreate被系统调用，所以这里重写这个函数，生成两个数据库表单，一个是便签表单，另一个是数据表单
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+//        数据库已经存在，且升级（version提高）的时候才会执行此函数
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
+
+        if (oldVersion == 1) {
+            upgradeToV2(db);
+            skipV2 = true; // this upgrade including the upgrade from v2 to v3
+            oldVersion++;
+        }
+
+        if (oldVersion == 2 && !skipV2) {
+            upgradeToV3(db);
+            reCreateTriggers = true;
+            oldVersion++;
+        }
+
+        if (oldVersion == 3) {
+            upgradeToV4(db);
+            oldVersion++;
+        }
+
+        if (reCreateTriggers) {
+//            若重构触发器的值为真，那么，要把便签（note）和数据（data）表单的数据库触发器重构，调用以上的定义
+            reCreateNoteTableTriggers(db);
+            reCreateDataTableTriggers(db);
+        }
+
+        if (oldVersion != newVersion) {
+//            当这个函数中的程序执行完后，判断是否版本升级成功，若版本号没有升级到相应new版本，这个就会抛出异常IllegalStateException，意思是方法接收到错误参数
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+    private void upgradeToV2(SQLiteDatabase db) {
+//        将数据库的版本更新到V2
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    private void upgradeToV3(SQLiteDatabase db) {
+//        比版本2，版本3升级多了好几个功能
+        // 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");
+        // add a column for gtask id
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // add a trash system folder
+        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);
+    }
+
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}

doc/韩嘉辉注释的代码/NotesProvider.java

@@ -0,0 +1,348 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+//便签信息提供类
+package net.micode.notes.data;
+
+
+import android.app.SearchManager;
+import android.content.ContentProvider;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.NotesDatabaseHelper.TABLE;
+
+
+public class NotesProvider extends ContentProvider {
+//    为存储和获取数据提供接口。可以在不同的应用程序之间共享数据
+//            ContentProvider提供的方法
+//    query：查询
+//    insert：插入
+//    update：更新
+//    delete：删除
+//    getType：得到数据类型
+    private static final UriMatcher mMatcher;
+//    识别所需的URI，本质上是基于正则表达式的字符串识别的工具
+    private NotesDatabaseHelper mHelper;
+//    我们自定义的数据库助手类在这里实例化
+
+    private static final String TAG = "NotesProvider";
+//    TAG用来做输出日志的log函数的第一个实参
+    private static final int URI_NOTE            = 1;
+//    1-6全部是Uri资源的id
+    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 {
+//        我们在使用uriMatcher时，先把需要匹配Uri路径全部给注册上
+        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
+        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);
+    }
+
+    /**
+     * 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.
+     */
+    private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
+//    构造查询语句，在安卓自带的搜索框中显示小米便签的搜索项目
+        + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","
+        + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+        + 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;
+
+    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+//    声明NOTES_SNIPPET_SEARCH_QUERY，便签搜索查询
+        + " FROM " + TABLE.NOTE
+        + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
+        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+
+    @Override
+    public boolean onCreate() {
+//        用于创建一个数据库NotesDatabse, 使用定义的getInstance方法
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+//                        查询uri在数据库中对应的位置
+            String sortOrder) {
+        Cursor c = null;
+        SQLiteDatabase db = mHelper.getReadableDatabase();
+//        实例化一个可读的数据库，其实根据上述onCreate实例化的单例，我们可以看出此处的db就是我们放入数据的db
+        String id = null;
+        switch (mMatcher.match(uri)) {
+//            根据URI来匹配查找的模式
+            case URI_NOTE:
+//                此处是查询多个便签，因为他没有指明具体ID
+                c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_NOTE_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_DATA:
+                c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_SEARCH:
+            case URI_SEARCH_SUGGEST:
+                if (sortOrder != null || projection != null) {
+                    throw new IllegalArgumentException(
+                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                }
+
+                String searchString = null;
+                if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
+//                    对sortOrder和projection不能赋值，否则就抛出异常
+                    if (uri.getPathSegments().size() > 1) {
+                        searchString = uri.getPathSegments().get(1);
+                    }
+                } else {
+                    searchString = uri.getQueryParameter("pattern");
+                }
+
+                if (TextUtils.isEmpty(searchString)) {
+                    return null;
+                }
+
+                try {
+                    searchString = String.format("%%%s%%", searchString);
+                    c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
+                            new String[] { searchString });
+                } catch (IllegalStateException ex) {
+                    Log.e(TAG, "got exception: " + ex.toString());
+                }
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (c != null) {
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+//        声明一个插入Uri
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+//        其中getWritableDatabase() 方法以读写方式打开数据库，一旦数据库的磁盘空间满了，数据库就只能读而不能写，倘若使用的是getWritableDatabase() 方法就会出错。
+        long dataId = 0, noteId = 0, insertedId = 0;
+        switch (mMatcher.match(uri)) {
+//            根据uri的匹配结果，对应于上面定义的常量，采取不同的对应动作
+            case URI_NOTE:
+                insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+                break;
+            case URI_DATA:
+                if (values.containsKey(DataColumns.NOTE_ID)) {
+                    noteId = values.getAsLong(DataColumns.NOTE_ID);
+                } else {
+                    Log.d(TAG, "Wrong data format without note id:" + values.toString());
+                }
+                insertedId = dataId = db.insert(TABLE.DATA, null, values);
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        // Notify the note uri
+        if (noteId > 0) {
+//            notifyChange获得一个ContextResolver对象并且更新里面的内容
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+        // Notify the data uri
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+        return ContentUris.withAppendedId(uri, insertedId);
+    }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+//        声明一个删除uri
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+//        获取可写的数据库
+        boolean deleteData = false;
+//        bool类型的常量，标志是否删除数据
+        switch (mMatcher.match(uri)) {
+//            查找匹配的uri
+            case URI_NOTE:
+                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                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);
+                if (noteId <= 0) {
+                    break;
+                }
+                count = db.delete(TABLE.NOTE,
+                        NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                break;
+            case URI_DATA:
+                count = db.delete(TABLE.DATA, selection, selectionArgs);
+                deleteData = true;
+                break;
+            case URI_DATA_ITEM:
+                id = uri.getPathSegments().get(1);
+                count = db.delete(TABLE.DATA,
+                        DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                deleteData = true;
+                break;
+            default:
+//                否则抛出异常，表示未知uri
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (count > 0) {
+//            代码段：对上述的操作进行判断，如果上述更改发生则count>0
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+//        声明版本升级URI
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+//        创建可读可写的数据库
+        boolean updateData = false;
+        switch (mMatcher.match(uri)) {
+//            根据不同的uri，更新数据库
+            case URI_NOTE:
+//                如果是便签类型，先升级，然后更新数据库
+                increaseNoteVersion(-1, selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+//                便签条目类型，则先获取对应便签id，然后升级，更新数据库
+                id = uri.getPathSegments().get(1);
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                break;
+            case URI_DATA:
+//                多个数据进行了修改
+                count = db.update(TABLE.DATA, values, selection, selectionArgs);
+                updateData = true;
+                break;
+            case URI_DATA_ITEM:
+//                指定数据进行了修改
+                id = uri.getPathSegments().get(1);
+                count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                updateData = true;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+
+        if (count > 0) {
+            if (updateData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    private String parseSelection(String selection) {
+//        将字符串解析成规定格式
+        return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+    }
+
+    private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+//        通过所给的ID等信息增加便签版本内容
+        StringBuilder sql = new StringBuilder(120);
+//        StringBuilder：适用于单线程下在字符缓冲区进行大量操作的情况，运行速度比String快
+        sql.append("UPDATE ");
+        sql.append(TABLE.NOTE);
+        sql.append(" SET ");
+        sql.append(NoteColumns.VERSION);
+        sql.append("=" + NoteColumns.VERSION + "+1 ");
+
+        if (id > 0 || !TextUtils.isEmpty(selection)) {
+//            操作条件selection不为空或者ID>0，增加WHERE语句
+            sql.append(" WHERE ");
+        }
+        if (id > 0) {
+//            ID>0，则添加ID
+            sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+        }
+        if (!TextUtils.isEmpty(selection)) {
+//            若selection字段为空，则添加该字段
+            String selectString = id > 0 ? parseSelection(selection) : selection;
+            for (String args : selectionArgs) {
+                selectString = selectString.replaceFirst("\\?", args);
+            }
+            sql.append(selectString);
+        }
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());
+//        把修改后的sql加入数据库
+    }
+
+    @Override
+    public String getType(Uri uri) {
+//        仅仅只是声明gettype，并无其他操作
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}

doc/韩嘉辉注释的代码/SqlData.java

@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.NotesDatabaseHelper.TABLE;
+import net.micode.notes.gtask.exception.ActionFailureException;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+
+/*
+ * Description：用于支持小米便签最底层的数据库相关操作，和sqlnote的关系上是子集关系，即data是note的子集（节点）。
+ * SqlData其实就是也就是所谓数据中的数据
+ */
+
+public class SqlData {
+    /*
+     * 功能描述：得到类的简写名称存入字符串TAG中
+     * 实现过程：调用getSimpleName ()函数
+     * Made By CuiCan
+     */
+    private static final String TAG = SqlData.class.getSimpleName();
+
+    private static final int INVALID_ID = -99999;//为mDataId置初始值-99999
+
+
+    /**
+     * 来自Notes类中定义的DataColumn中的一些常量
+     */
+
+    // 集合了interface DataColumns中所有SF常量
+    public static final String[] PROJECTION_DATA = new String[] {
+            DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1,
+            DataColumns.DATA3
+    };
+
+    /**
+     * 以下五个变量作为sql表中5列的编号
+     */
+    public static final int DATA_ID_COLUMN = 0;
+
+    public static final int DATA_MIME_TYPE_COLUMN = 1;
+
+    public static final int DATA_CONTENT_COLUMN = 2;
+
+    public static final int DATA_CONTENT_DATA_1_COLUMN = 3;
+
+    public static final int DATA_CONTENT_DATA_3_COLUMN = 4;
+
+    private ContentResolver mContentResolver;
+    //判断是否直接用Content生成，是为true，否则为false
+    private boolean mIsCreate;
+
+    private long mDataId;
+
+    private String mDataMimeType;
+
+    private String mDataContent;
+
+    private long mDataContentData1;
+
+    private String mDataContentData3;
+
+    private ContentValues mDiffDataValues;
+
+    /*
+     * 功能描述：构造函数，用于初始化数据
+     * 参数注解：mContentResolver用于获取ContentProvider提供的数据
+     * 参数注解： mIsCreate表征当前数据是用哪种方式创建（两种构造函数的参数不同）
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public SqlData(Context context) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;
+        mDataId = INVALID_ID;//mDataId置初始值-99999
+        mDataMimeType = DataConstants.NOTE;
+        mDataContent = "";
+        mDataContentData1 = 0;
+        mDataContentData3 = "";
+        mDiffDataValues = new ContentValues();
+    }
+
+
+    /*
+     * 功能描述：构造函数，初始化数据
+     * 参数注解：mContentResolver用于获取ContentProvider提供的数据
+     * 参数注解： mIsCreate表征当前数据是用哪种方式创建（两种构造函数的参数不同）
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public SqlData(Context context, Cursor c) {
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(c);
+        mDiffDataValues = new ContentValues();
+    }
+
+    /*
+     * 功能描述：从光标处加载数据
+     * 从当前的光标处将五列的数据加载到该类的对象
+     * Made By CuiCan
+     */
+    private void loadFromCursor(Cursor c) {
+        mDataId = c.getLong(DATA_ID_COLUMN);
+        mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN);
+        mDataContent = c.getString(DATA_CONTENT_COLUMN);
+        mDataContentData1 = c.getLong(DATA_CONTENT_DATA_1_COLUMN);
+        mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN);
+    }
+
+
+    /*
+     * 功能描述：设置用于共享的数据，并提供异常抛出与处理机制
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void setContent(JSONObject js) throws JSONException {
+        //如果传入的JSONObject对象中有DataColumns.ID这一项，则设置，否则设为INVALID_ID
+        long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID;
+        if (mIsCreate || mDataId != dataId) {
+            mDiffDataValues.put(DataColumns.ID, dataId);
+        }
+        mDataId = dataId;
+
+        String dataMimeType = js.has(DataColumns.MIME_TYPE) ? js.getString(DataColumns.MIME_TYPE)
+                : DataConstants.NOTE;
+        if (mIsCreate || !mDataMimeType.equals(dataMimeType)) {
+            mDiffDataValues.put(DataColumns.MIME_TYPE, dataMimeType);
+        }
+        mDataMimeType = dataMimeType;
+
+        String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : "";
+        if (mIsCreate || !mDataContent.equals(dataContent)) {
+            mDiffDataValues.put(DataColumns.CONTENT, dataContent);
+        }
+        mDataContent = dataContent;
+
+        long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0;
+        if (mIsCreate || mDataContentData1 != dataContentData1) {
+            mDiffDataValues.put(DataColumns.DATA1, dataContentData1);
+        }
+        mDataContentData1 = dataContentData1;
+
+        String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : "";
+        if (mIsCreate || !mDataContentData3.equals(dataContentData3)) {
+            mDiffDataValues.put(DataColumns.DATA3, dataContentData3);
+        }
+        mDataContentData3 = dataContentData3;
+    }
+
+
+    /*
+     * 功能描述：获取共享的数据内容，并提供异常抛出与处理机制
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public JSONObject getContent() throws JSONException {
+        if (mIsCreate) {
+            Log.e(TAG, "it seems that we haven't created this in database yet");
+            return null;
+        }
+        //创建JSONObject对象。并将相关数据放入其中，并返回。
+        JSONObject js = new JSONObject();
+        js.put(DataColumns.ID, mDataId);
+        js.put(DataColumns.MIME_TYPE, mDataMimeType);
+        js.put(DataColumns.CONTENT, mDataContent);
+        js.put(DataColumns.DATA1, mDataContentData1);
+        js.put(DataColumns.DATA3, mDataContentData3);
+        return js;
+    }
+
+    /*
+     * 功能描述：commit函数用于把当前造作所做的修改保存到数据库
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void commit(long noteId, boolean validateVersion, long version) {
+
+        if (mIsCreate) {
+            if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) {
+                mDiffDataValues.remove(DataColumns.ID);
+            }
+
+            mDiffDataValues.put(DataColumns.NOTE_ID, noteId);
+            Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues);
+            try {
+                mDataId = Long.valueOf(uri.getPathSegments().get(1));
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString());
+                throw new ActionFailureException("create note failed");
+            }
+        } else {
+            if (mDiffDataValues.size() > 0) {
+                int result = 0;
+                if (!validateVersion) {
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null);
+                } else {
+                    result = mContentResolver.update(ContentUris.withAppendedId(
+                                    Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues,
+                            " ? in (SELECT " + NoteColumns.ID + " FROM " + TABLE.NOTE
+                                    + " WHERE " + NoteColumns.VERSION + "=?)", new String[] {
+                                    String.valueOf(noteId), String.valueOf(version)
+                            });
+                }
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
+                }
+            }
+        }
+
+        mDiffDataValues.clear();
+        mIsCreate = false;
+    }
+
+    /*
+     * 功能描述：获取当前id
+     * 实现过程：
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public long getId() {
+        return mDataId;
+    }
+}

doc/韩嘉辉注释的代码/SqlNote.java

@@ -0,0 +1,604 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+import net.micode.notes.tool.ResourceParser;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+
+
+public class SqlNote {
+    /*
+     * 功能描述：得到类的简写名称存入字符串TAG中
+     * 实现过程：调用getSimpleName ()函数
+     * Made By CuiCan
+     */
+    private static final String TAG = SqlNote.class.getSimpleName();
+
+    private static final int INVALID_ID = -99999;
+    // 集合了interface NoteColumns中所有SF常量（17个）
+    public static final String[] PROJECTION_NOTE = new String[] {
+            NoteColumns.ID, NoteColumns.ALERTED_DATE, NoteColumns.BG_COLOR_ID,
+            NoteColumns.CREATED_DATE, NoteColumns.HAS_ATTACHMENT, NoteColumns.MODIFIED_DATE,
+            NoteColumns.NOTES_COUNT, NoteColumns.PARENT_ID, NoteColumns.SNIPPET, NoteColumns.TYPE,
+            NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE, NoteColumns.SYNC_ID,
+            NoteColumns.LOCAL_MODIFIED, NoteColumns.ORIGIN_PARENT_ID, NoteColumns.GTASK_ID,
+            NoteColumns.VERSION
+    };
+
+    //以下设置17个列的编号
+    public static final int ID_COLUMN = 0;
+
+    public static final int ALERTED_DATE_COLUMN = 1;
+
+    public static final int BG_COLOR_ID_COLUMN = 2;
+
+    public static final int CREATED_DATE_COLUMN = 3;
+
+    public static final int HAS_ATTACHMENT_COLUMN = 4;
+
+    public static final int MODIFIED_DATE_COLUMN = 5;
+
+    public static final int NOTES_COUNT_COLUMN = 6;
+
+    public static final int PARENT_ID_COLUMN = 7;
+
+    public static final int SNIPPET_COLUMN = 8;
+
+    public static final int TYPE_COLUMN = 9;
+
+    public static final int WIDGET_ID_COLUMN = 10;
+
+    public static final int WIDGET_TYPE_COLUMN = 11;
+
+    public static final int SYNC_ID_COLUMN = 12;
+
+    public static final int LOCAL_MODIFIED_COLUMN = 13;
+
+    public static final int ORIGIN_PARENT_ID_COLUMN = 14;
+
+    public static final int GTASK_ID_COLUMN = 15;
+
+    public static final int VERSION_COLUMN = 16;
+
+    //一下定义了17个内部的变量，其中12个可以由content中获得，5个需要初始化为0或者new
+    private Context mContext;
+
+    private ContentResolver mContentResolver;
+
+    private boolean mIsCreate;
+
+    private long mId;
+
+    private long mAlertDate;
+
+    private int mBgColorId;
+
+    private long mCreatedDate;
+
+    private int mHasAttachment;
+
+    private long mModifiedDate;
+
+    private long mParentId;
+
+    private String mSnippet;
+
+    private int mType;
+
+    private int mWidgetId;
+
+    private int mWidgetType;
+
+    private long mOriginParent;
+
+    private long mVersion;
+
+    private ContentValues mDiffNoteValues;
+
+    private ArrayList<SqlData> mDataList;
+
+    /*
+     * 功能描述：构造函数
+     * 参数注解： mIsCreate用于标示构造方式
+     * 参数注解：
+     * Made By CuiCan
+     */
+    //构造函数只有context，对所有的变量进行初始化
+    public SqlNote(Context context) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = true;
+        mId = INVALID_ID;
+        mAlertDate = 0;
+        mBgColorId = ResourceParser.getDefaultBgId(context);
+        mCreatedDate = System.currentTimeMillis();//调用系统函数获得创建时间
+        mHasAttachment = 0;
+        mModifiedDate = System.currentTimeMillis();//最后一次修改时间初始化为创建时间
+        mParentId = 0;
+        mSnippet = "";
+        mType = Notes.TYPE_NOTE;
+        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
+        mOriginParent = 0;
+        mVersion = 0;
+        mDiffNoteValues = new ContentValues();
+        mDataList = new ArrayList<SqlData>();
+    }
+
+
+    /*
+     * 功能描述：构造函数
+     * 参数注解： mIsCreate用于标示构造方式
+     * 参数注解：
+     * Made By CuiCan
+     */
+    //构造函数有context和一个数据库的cursor，多数变量通过cursor指向的一条记录直接进行初始化
+    public SqlNote(Context context, Cursor c) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(c);
+        mDataList = new ArrayList<SqlData>();
+        //
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues();
+    }
+
+
+    /*
+     * 功能描述：构造函数
+     * 参数注解： mIsCreate用于标示构造方式
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public SqlNote(Context context, long id) {
+        mContext = context;
+        mContentResolver = context.getContentResolver();
+        mIsCreate = false;
+        loadFromCursor(id);
+        mDataList = new ArrayList<SqlData>();
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+        mDiffNoteValues = new ContentValues();
+
+    }
+
+    /*
+     * 功能描述：通过id从光标处加载数据
+     * Made By CuiCan
+     */
+    private void loadFromCursor(long id) {
+        Cursor c = null;
+        try {
+            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
+                    new String[] {
+                            String.valueOf(id)
+                    }, null);//通过id获得对应的ContentResolver中的cursor
+            if (c != null) {
+                c.moveToNext();
+                loadFromCursor(c);//然后加载数据进行初始化，这样函数
+                //SqlNote(Context context, long id)与SqlNote(Context context, long id)的实现方式基本相同
+            } else {
+                Log.w(TAG, "loadFromCursor: cursor = null");
+            }
+        } finally {
+            if (c != null)
+                c.close();
+        }
+    }
+
+    /*
+     * 功能描述：通过游标从光标处加载数据
+     * Made By CuiCan
+     */
+    private void loadFromCursor(Cursor c) {
+        //直接从一条记录中的获得以下变量的初始值
+        mId = c.getLong(ID_COLUMN);
+        mAlertDate = c.getLong(ALERTED_DATE_COLUMN);
+        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN);
+        mCreatedDate = c.getLong(CREATED_DATE_COLUMN);
+        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN);
+        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN);
+        mParentId = c.getLong(PARENT_ID_COLUMN);
+        mSnippet = c.getString(SNIPPET_COLUMN);
+        mType = c.getInt(TYPE_COLUMN);
+        mWidgetId = c.getInt(WIDGET_ID_COLUMN);
+        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN);
+        mVersion = c.getLong(VERSION_COLUMN);
+    }
+
+    /*
+     * 功能描述：通过content机制获取共享数据并加载到数据库当前游标处
+     * 参数注解：
+     * Made By CuiCan
+     */
+    private void loadDataContent() {
+        Cursor c = null;
+        mDataList.clear();
+        try {
+            c = mContentResolver.query(Notes.CONTENT_DATA_URI, SqlData.PROJECTION_DATA,
+                    "(note_id=?)", new String[] {
+                            String.valueOf(mId)
+                    }, null);
+            if (c != null) {
+                if (c.getCount() == 0) {
+                    Log.w(TAG, "it seems that the note has not data");
+                    return;
+                }
+                while (c.moveToNext()) {
+                    SqlData data = new SqlData(mContext, c);
+                    mDataList.add(data);
+                }
+            } else {
+                Log.w(TAG, "loadDataContent: cursor = null");
+            }
+        } finally {
+            if (c != null)
+                c.close();
+        }
+    }
+
+    /*
+     * 功能描述：设置通过content机制用于共享的数据信息
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public boolean setContent(JSONObject js) {
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                Log.w(TAG, "cannot set system folder");
+            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                // for folder we can only update the snnipet and type
+                String snippet = note.has(NoteColumns.SNIPPET) ? note
+                        .getString(NoteColumns.SNIPPET) : "";
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+
+                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE;
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_NOTE) {
+                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+                long id = note.has(NoteColumns.ID) ? note.getLong(NoteColumns.ID) : INVALID_ID;
+                if (mIsCreate || mId != id) {
+                    mDiffNoteValues.put(NoteColumns.ID, id);
+                }
+                mId = id;
+
+                long alertDate = note.has(NoteColumns.ALERTED_DATE) ? note
+                        .getLong(NoteColumns.ALERTED_DATE) : 0;
+                if (mIsCreate || mAlertDate != alertDate) {
+                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate);
+                }
+                mAlertDate = alertDate;
+
+                int bgColorId = note.has(NoteColumns.BG_COLOR_ID) ? note
+                        .getInt(NoteColumns.BG_COLOR_ID) : ResourceParser.getDefaultBgId(mContext);
+                if (mIsCreate || mBgColorId != bgColorId) {
+                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId);
+                }
+                mBgColorId = bgColorId;
+                long createDate = note.has(NoteColumns.CREATED_DATE) ? note
+                        .getLong(NoteColumns.CREATED_DATE) : System.currentTimeMillis();
+                if (mIsCreate || mCreatedDate != createDate) {
+                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate);
+                }
+                mCreatedDate = createDate;
+
+                int hasAttachment = note.has(NoteColumns.HAS_ATTACHMENT) ? note
+                        .getInt(NoteColumns.HAS_ATTACHMENT) : 0;
+                if (mIsCreate || mHasAttachment != hasAttachment) {
+                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment);
+                }
+                mHasAttachment = hasAttachment;
+
+                long modifiedDate = note.has(NoteColumns.MODIFIED_DATE) ? note
+                        .getLong(NoteColumns.MODIFIED_DATE) : System.currentTimeMillis();
+                if (mIsCreate || mModifiedDate != modifiedDate) {
+                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate);
+                }
+                mModifiedDate = modifiedDate;
+
+                long parentId = note.has(NoteColumns.PARENT_ID) ? note
+                        .getLong(NoteColumns.PARENT_ID) : 0;
+                if (mIsCreate || mParentId != parentId) {
+                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId);
+                }
+                mParentId = parentId;
+
+                String snippet = note.has(NoteColumns.SNIPPET) ? note
+                        .getString(NoteColumns.SNIPPET) : "";
+                if (mIsCreate || !mSnippet.equals(snippet)) {
+                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
+                }
+                mSnippet = snippet;
+
+                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
+                        : Notes.TYPE_NOTE;
+                if (mIsCreate || mType != type) {
+                    mDiffNoteValues.put(NoteColumns.TYPE, type);
+                }
+                mType = type;
+
+                int widgetId = note.has(NoteColumns.WIDGET_ID) ? note.getInt(NoteColumns.WIDGET_ID)
+                        : AppWidgetManager.INVALID_APPWIDGET_ID;
+                if (mIsCreate || mWidgetId != widgetId) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId);
+                }
+                mWidgetId = widgetId;
+
+                int widgetType = note.has(NoteColumns.WIDGET_TYPE) ? note
+                        .getInt(NoteColumns.WIDGET_TYPE) : Notes.TYPE_WIDGET_INVALIDE;
+                if (mIsCreate || mWidgetType != widgetType) {
+                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType);
+                }
+                mWidgetType = widgetType;
+
+                long originParent = note.has(NoteColumns.ORIGIN_PARENT_ID) ? note
+                        .getLong(NoteColumns.ORIGIN_PARENT_ID) : 0;
+                if (mIsCreate || mOriginParent != originParent) {
+                    mDiffNoteValues.put(NoteColumns.ORIGIN_PARENT_ID, originParent);
+                }
+                mOriginParent = originParent;
+
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    SqlData sqlData = null;
+                    if (data.has(DataColumns.ID)) {
+                        long dataId = data.getLong(DataColumns.ID);
+                        for (SqlData temp : mDataList) {
+                            if (dataId == temp.getId()) {
+                                sqlData = temp;
+                            }
+                        }
+                    }
+
+                    if (sqlData == null) {
+                        sqlData = new SqlData(mContext);
+                        mDataList.add(sqlData);
+                    }
+
+                    sqlData.setContent(data);
+                }
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return false;
+        }
+        return true;
+    }
+
+    /*
+     * 功能描述：获取content机制提供的数据并加载到note中
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public JSONObject getContent() {
+        try {
+            JSONObject js = new JSONObject();
+
+            if (mIsCreate) {
+                Log.e(TAG, "it seems that we haven't created this in database yet");
+                return null;
+            }
+
+            JSONObject note = new JSONObject();
+            if (mType == Notes.TYPE_NOTE) {//类型为note时
+                note.put(NoteColumns.ID, mId);
+                note.put(NoteColumns.ALERTED_DATE, mAlertDate);
+                note.put(NoteColumns.BG_COLOR_ID, mBgColorId);
+                note.put(NoteColumns.CREATED_DATE, mCreatedDate);
+                note.put(NoteColumns.HAS_ATTACHMENT, mHasAttachment);
+                note.put(NoteColumns.MODIFIED_DATE, mModifiedDate);
+                note.put(NoteColumns.PARENT_ID, mParentId);
+                note.put(NoteColumns.SNIPPET, mSnippet);
+                note.put(NoteColumns.TYPE, mType);
+                note.put(NoteColumns.WIDGET_ID, mWidgetId);
+                note.put(NoteColumns.WIDGET_TYPE, mWidgetType);
+                note.put(NoteColumns.ORIGIN_PARENT_ID, mOriginParent);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+
+                JSONArray dataArray = new JSONArray();
+                for (SqlData sqlData : mDataList) {
+                    JSONObject data = sqlData.getContent();
+                    if (data != null) {
+                        dataArray.put(data);
+                    }
+                }
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
+            } else if (mType == Notes.TYPE_FOLDER || mType == Notes.TYPE_SYSTEM) {//类型为文件夹或者
+                note.put(NoteColumns.ID, mId);
+                note.put(NoteColumns.TYPE, mType);
+                note.put(NoteColumns.SNIPPET, mSnippet);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+            }
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    /*
+     * 功能描述：给当前id设置父id
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void setParentId(long id) {
+        mParentId = id;
+        mDiffNoteValues.put(NoteColumns.PARENT_ID, id);
+    }
+
+    /*
+     * 功能描述：给当前id设置Gtaskid
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void setGtaskId(String gid) {
+        mDiffNoteValues.put(NoteColumns.GTASK_ID, gid);
+    }
+
+    /*
+     * 功能描述：给当前id设置同步id
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void setSyncId(long syncId) {
+        mDiffNoteValues.put(NoteColumns.SYNC_ID, syncId);
+    }
+
+    /*
+     * 功能描述：初始化本地修改，即撤销所有当前修改
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void resetLocalModified() {
+        mDiffNoteValues.put(NoteColumns.LOCAL_MODIFIED, 0);
+    }
+
+    /*
+     * 功能描述：获得当前id
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public long getId() {
+        return mId;
+    }
+
+    /*
+     * 功能描述：获得当前id的父id
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public long getParentId() {
+        return mParentId;
+    }
+
+    /*
+     * 功能描述：获取小片段即用于显示的部分便签内容
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public String getSnippet() {
+        return mSnippet;
+    }
+
+    /*
+     * 功能描述：判断是否为便签类型
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public boolean isNoteType() {
+        return mType == Notes.TYPE_NOTE;
+    }
+
+    /*
+     * 功能描述：commit函数用于把当前造作所做的修改保存到数据库
+     * 参数注解：
+     * Made By CuiCan
+     */
+    public void commit(boolean validateVersion) {
+        if (mIsCreate) {
+            if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
+                mDiffNoteValues.remove(NoteColumns.ID);
+            }
+
+            Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues);
+            try {
+                mId = Long.valueOf(uri.getPathSegments().get(1));
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "Get note id error :" + e.toString());
+                throw new ActionFailureException("create note failed");
+            }
+            if (mId == 0) {
+                throw new IllegalStateException("Create thread id failed");
+            }
+
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {//直接使用sqldata中的实现
+                    sqlData.commit(mId, false, -1);
+                }
+            }
+        } else {
+            if (mId <= 0 && mId != Notes.ID_ROOT_FOLDER && mId != Notes.ID_CALL_RECORD_FOLDER) {
+                Log.e(TAG, "No such note");
+                throw new IllegalStateException("Try to update note with invalid id");
+            }
+            if (mDiffNoteValues.size() > 0) {
+                mVersion ++;
+                int result = 0;
+                if (!validateVersion) {//构造字符串
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                            + NoteColumns.ID + "=?)", new String[] {
+                            String.valueOf(mId)
+                    });
+                } else {
+                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
+                                    + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
+                            new String[] {
+                                    String.valueOf(mId), String.valueOf(mVersion)
+                            });
+                }
+                if (result == 0) {
+                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
+                }
+            }
+
+            if (mType == Notes.TYPE_NOTE) {
+                for (SqlData sqlData : mDataList) {
+                    sqlData.commit(mId, validateVersion, mVersion);
+                }
+            }
+        }
+
+        // refresh local info
+        loadFromCursor(mId);
+        if (mType == Notes.TYPE_NOTE)
+            loadDataContent();
+
+        mDiffNoteValues.clear();
+        mIsCreate = false;
+    }
+}

doc/韩嘉辉注释的代码/Task.java

@@ -0,0 +1,355 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.DataConstants;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+
+public class Task extends Node {
+    private static final String TAG = Task.class.getSimpleName();
+
+    private boolean mCompleted;//是否完成
+
+    private String mNotes;
+
+    private JSONObject mMetaInfo;//将在实例中存储数据的类型
+
+    private Task mPriorSibling;//对应的优先兄弟Task的指针（待完善）
+
+    private TaskList mParent;//所在的任务列表的指针
+
+    public Task() {
+        super();
+        mCompleted = false;
+        mNotes = null;
+        mPriorSibling = null;//TaskList中当前Task前面的Task的指针
+        mParent = null;//当前Task所在的TaskList
+        mMetaInfo = null;
+    }
+
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // index
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mParent.getChildTaskIndex(this));
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_TASK);
+            if (getNotes() != null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+            }
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+            // parent_id
+            if (mParent!= null) {
+                js.put(GTaskStringUtils.GTASK_JSON_PARENT_ID, mParent.getGid());
+            }
+
+            // dest_parent_type
+            js.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+
+            // list_id
+            if (mParent!= null) {
+                js.put(GTaskStringUtils.GTASK_JSON_LIST_ID, mParent.getGid());
+            }
+
+            // prior_sibling_id
+            if (mPriorSibling != null) {
+                js.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, mPriorSibling.getGid());
+            }
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate task-create jsonobject");
+        }
+
+        return js;
+    }
+
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // id
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            if (getNotes() != null) {
+                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
+            }
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate task-update jsonobject");
+        }
+
+        return js;
+    }
+
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js != null) {
+            try {
+                // id
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+                // last_modified
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+                // name
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+                // notes
+                if (js.has(GTaskStringUtils.GTASK_JSON_NOTES)) {
+                    setNotes(js.getString(GTaskStringUtils.GTASK_JSON_NOTES));
+                }
+
+                // deleted
+                if (js.has(GTaskStringUtils.GTASK_JSON_DELETED)) {
+                    setDeleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_DELETED));
+                }
+
+                // completed
+                if (js.has(GTaskStringUtils.GTASK_JSON_COMPLETED)) {
+                    setCompleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_COMPLETED));
+                }
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("fail to get task content from jsonobject");
+            }
+        }
+    }
+
+    public void setContentByLocalJSON(JSONObject js) {    //<2F><>metadata<74><61><EFBFBD><EFBFBD>ʵʩ
+        if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)
+                || !js.has(GTaskStringUtils.META_HEAD_DATA)) {
+            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
+        }
+
+        try {
+            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+            if (note.getInt(NoteColumns.TYPE) != Notes.TYPE_NOTE) {
+                Log.e(TAG, "invalid type");
+                return;
+            }
+
+            for (int i = 0; i < dataArray.length(); i++) {
+                JSONObject data = dataArray.getJSONObject(i);
+                if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                    setName(data.getString(DataColumns.CONTENT));
+                    break;
+                }
+            }
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+    public JSONObject getLocalJSONFromContent() {
+        String name = getName();
+        try {
+            if (mMetaInfo == null) {
+                // new task created from web
+                if (name == null) {
+                    Log.w(TAG, "the note seems to be an empty one");
+                    return null;
+                }
+
+                JSONObject js = new JSONObject();
+                JSONObject note = new JSONObject();
+                JSONArray dataArray = new JSONArray();
+                JSONObject data = new JSONObject();
+                data.put(DataColumns.CONTENT, name);
+                dataArray.put(data);
+                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
+                return js;
+            } else {
+                // synced task
+                JSONObject note = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+                JSONArray dataArray = mMetaInfo.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
+
+                for (int i = 0; i < dataArray.length(); i++) {
+                    JSONObject data = dataArray.getJSONObject(i);
+                    if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
+                        data.put(DataColumns.CONTENT, getName());
+                        break;
+                    }
+                }
+
+                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+                return mMetaInfo;
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public void setMetaInfo(MetaData metaData) {
+        if (metaData != null && metaData.getNotes() != null) {
+            try {
+                mMetaInfo = new JSONObject(metaData.getNotes());
+            } catch (JSONException e) {
+                Log.w(TAG, e.toString());
+                mMetaInfo = null;
+            }
+        }
+    }
+
+    public int getSyncAction(Cursor c) {
+        try {
+            JSONObject noteInfo = null;
+            if (mMetaInfo != null && mMetaInfo.has(GTaskStringUtils.META_HEAD_NOTE)) {
+                noteInfo = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+            }
+
+            if (noteInfo == null) {
+                Log.w(TAG, "it seems that note meta has been deleted");
+                return SYNC_ACTION_UPDATE_REMOTE;
+            }
+
+            if (!noteInfo.has(NoteColumns.ID)) {
+                Log.w(TAG, "remote note id seems to be deleted");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+            // validate the note id now
+            if (c.getLong(SqlNote.ID_COLUMN) != noteInfo.getLong(NoteColumns.ID)) {
+                Log.w(TAG, "note id doesn't match");
+                return SYNC_ACTION_UPDATE_LOCAL;
+            }
+
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // there is no local update
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // no update both side
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // apply remote to local
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // validate gtask id
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "gtask id doesn't match");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // local modification only
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    return SYNC_ACTION_UPDATE_CONFLICT;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+        return SYNC_ACTION_ERROR;
+    }
+
+    public boolean isWorthSaving() {
+        return mMetaInfo != null || (getName() != null && getName().trim().length() > 0)
+                || (getNotes() != null && getNotes().trim().length() > 0);
+    }
+
+    public void setCompleted(boolean completed) {
+        this.mCompleted = completed;
+    }
+
+    public void setNotes(String notes) {
+        this.mNotes = notes;
+    }
+
+    public void setPriorSibling(Task priorSibling) {
+        this.mPriorSibling = priorSibling;
+    }
+
+    public void setParent(TaskList parent) {
+        this.mParent = parent;
+    }
+
+    public boolean getCompleted() {
+        return this.mCompleted;
+    }
+
+    public String getNotes() {
+        return this.mNotes;
+    }
+
+    public Task getPriorSibling() {
+        return this.mPriorSibling;
+    }
+
+    public TaskList getParent() {
+        return this.mParent;
+    }
+
+}

doc/韩嘉辉注释的代码/TaskList.java

@@ -0,0 +1,400 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.gtask.data;
+
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.gtask.exception.ActionFailureException;
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+
+
+public class TaskList extends Node {
+    private static final String TAG = TaskList.class.getSimpleName();//tag标记
+
+    private int mIndex;//当前TaskList的指针
+
+    private ArrayList<Task> mChildren;//类中主要的保存数据的单元，用来实现一个以Task为元素的ArrayList
+
+    public TaskList() {
+        super();
+        mChildren = new ArrayList<Task>();
+        mIndex = 1;
+    }
+
+    /* (non-Javadoc)
+     * @see net.micode.notes.gtask.data.Node#getCreateAction(int)
+     * 生成并返回一个包含了一定数据的JSONObject实体
+     */
+    public JSONObject getCreateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // index
+            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mIndex);
+
+            // entity_delta
+            JSONObject entity = new JSONObject();//entity实体
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
+            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
+                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate tasklist-create jsonobject");
+        }
+
+        return js;
+    }
+
+    /* (non-Javadoc)
+     * @see net.micode.notes.gtask.data.Node#getUpdateAction(int)
+     * 生成并返回一个包含了一定数据的JSONObject实体
+     */
+    public JSONObject getUpdateAction(int actionId) {
+        JSONObject js = new JSONObject();
+
+        try {
+            // action_type
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
+                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);
+
+            // action_id
+            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);
+
+            // id
+            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());
+
+            // entity_delta
+            JSONObject entity = new JSONObject();
+            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
+            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
+            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);
+
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            throw new ActionFailureException("fail to generate tasklist-update jsonobject");
+        }
+
+        return js;
+    }
+
+    public void setContentByRemoteJSON(JSONObject js) {
+        if (js != null) {
+            try {
+                // id
+                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
+                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
+                }
+
+                // last_modified
+                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
+                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
+                }
+
+                // name
+                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
+                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
+                }
+
+            } catch (JSONException e) {
+                Log.e(TAG, e.toString());
+                e.printStackTrace();
+                throw new ActionFailureException("fail to get tasklist content from jsonobject");
+            }
+        }
+    }
+
+    public void setContentByLocalJSON(JSONObject js) {
+        if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)) {
+            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
+        }
+
+        try {
+            JSONObject folder = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
+
+            if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
+                String name = folder.getString(NoteColumns.SNIPPET);
+                setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + name);
+            } else if (folder.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
+                if (folder.getLong(NoteColumns.ID) == Notes.ID_ROOT_FOLDER)
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT);
+                else if (folder.getLong(NoteColumns.ID) == Notes.ID_CALL_RECORD_FOLDER)
+                    setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX
+                            + GTaskStringUtils.FOLDER_CALL_NOTE);
+                else
+                    Log.e(TAG, "invalid system folder");
+            } else {
+                Log.e(TAG, "error type");
+            }
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+    }
+
+    public JSONObject getLocalJSONFromContent() {
+        try {
+            JSONObject js = new JSONObject();
+            JSONObject folder = new JSONObject();
+
+            String folderName = getName();
+            if (getName().startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX))
+                folderName = folderName.substring(GTaskStringUtils.MIUI_FOLDER_PREFFIX.length(),
+                        folderName.length());
+            folder.put(NoteColumns.SNIPPET, folderName);
+            if (folderName.equals(GTaskStringUtils.FOLDER_DEFAULT)
+                    || folderName.equals(GTaskStringUtils.FOLDER_CALL_NOTE))
+                folder.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+            else
+                folder.put(NoteColumns.TYPE, Notes.TYPE_FOLDER);
+
+            js.put(GTaskStringUtils.META_HEAD_NOTE, folder);
+
+            return js;
+        } catch (JSONException e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public int getSyncAction(Cursor c) {
+        try {
+            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
+                // there is no local update
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // no update both side
+                    return SYNC_ACTION_NONE;
+                } else {
+                    // apply remote to local
+                    return SYNC_ACTION_UPDATE_LOCAL;
+                }
+            } else {
+                // validate gtask id
+                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
+                    Log.e(TAG, "gtask id doesn't match");
+                    return SYNC_ACTION_ERROR;
+                }
+                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
+                    // local modification only
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                } else {
+                    // for folder conflicts, just apply local modification
+                    return SYNC_ACTION_UPDATE_REMOTE;
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, e.toString());
+            e.printStackTrace();
+        }
+
+        return SYNC_ACTION_ERROR;
+    }
+
+    /**
+     * @return
+     * 功能：获得TaskList的大小，即mChildren的大小
+     */
+    public int getChildTaskCount() {
+        return mChildren.size();
+    }
+
+    /**
+     * @param task
+     * @return 返回值为是否成功添加任务。
+     * 功能：在当前任务表末尾添加新的任务。
+     */
+    public boolean addChildTask(Task task) {
+        boolean ret = false;
+        if (task != null && !mChildren.contains(task)) {
+            ret = mChildren.add(task);
+            if (ret) {
+                // need to set prior sibling and parent
+                task.setPriorSibling(mChildren.isEmpty() ? null : mChildren
+                        .get(mChildren.size() - 1));
+                task.setParent(this);
+                //注意：每一次ArrayList的变化都要紧跟相关Task中PriorSibling的更改
+                //，接下来几个函数都有相关操作
+            }
+        }
+        return ret;
+    }
+
+    /**
+     * @param task
+     * @param index
+     * @return
+     * 功能：在当前任务表的指定位置添加新的任务。
+     */
+    public boolean addChildTask(Task task, int index) {
+        if (index < 0 || index > mChildren.size()) {
+            Log.e(TAG, "add child task: invalid index");
+            return false;
+        }
+
+        int pos = mChildren.indexOf(task);
+        if (task != null && pos == -1) {
+            mChildren.add(index, task);
+
+            // update the task list
+            Task preTask = null;
+            Task afterTask = null;
+            if (index != 0)
+                preTask = mChildren.get(index - 1);
+            if (index != mChildren.size() - 1)
+                afterTask = mChildren.get(index + 1);
+
+            task.setPriorSibling(preTask);
+            if (afterTask != null)
+                afterTask.setPriorSibling(task);
+        }
+
+        return true;
+    }
+
+    /**
+     * @param task
+     * @return 返回删除是否成功
+     * 功能：删除TaskList中的一个Task
+     */
+    public boolean removeChildTask(Task task) {
+        boolean ret = false;
+        int index = mChildren.indexOf(task);
+        if (index != -1) {
+            ret = mChildren.remove(task);
+
+            if (ret) {
+                // reset prior sibling and parent
+                task.setPriorSibling(null);
+                task.setParent(null);
+
+                // update the task list
+                if (index != mChildren.size()) {
+                    mChildren.get(index).setPriorSibling(
+                            index == 0 ? null : mChildren.get(index - 1));
+                }
+            }
+        }
+        return ret;
+    }
+
+    /**
+     * @param task
+     * @param index
+     * @return
+     * 功能：将当前TaskList中含有的某个Task移到index位置
+     */
+    public boolean moveChildTask(Task task, int index) {
+
+        if (index < 0 || index >= mChildren.size()) {
+            Log.e(TAG, "move child task: invalid index");
+            return false;
+        }
+
+        int pos = mChildren.indexOf(task);
+        if (pos == -1) {
+            Log.e(TAG, "move child task: the task should in the list");
+            return false;
+        }
+
+        if (pos == index)
+            return true;
+        return (removeChildTask(task) && addChildTask(task, index));
+        //利用已实现好的功能完成当下功能；
+    }
+
+    /**
+     * @param gid
+     * @return返回寻找结果
+     * 功能：按gid寻找Task
+     */
+    public Task findChildTaskByGid(String gid) {
+        for (int i = 0; i < mChildren.size(); i++) {
+            Task t = mChildren.get(i);
+            if (t.getGid().equals(gid)) {
+                return t;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * @param task
+     * @return
+     * 功能：返回指定Task的index
+     */
+    public int getChildTaskIndex(Task task) {
+        return mChildren.indexOf(task);
+    }
+
+    /**
+     * @param index
+     * @return
+     * 功能：返回指定index的Task
+     */
+    public Task getChildTaskByIndex(int index) {
+        if (index < 0 || index >= mChildren.size()) {
+            Log.e(TAG, "getTaskByIndex: invalid index");
+            return null;
+        }
+        return mChildren.get(index);
+    }
+
+    /**
+     * @param gid
+     * @return
+     * 功能：返回指定gid的Task
+     */
+    public Task getChilTaskByGid(String gid) {
+        for (Task task : mChildren) {//一种常见的ArrayList的遍历方法（四种，见精读笔记）
+            if (task.getGid().equals(gid))
+                return task;
+        }
+        return null;
+    }
+
+    public ArrayList<Task> getChildTaskList() {
+        return this.mChildren;
+    }
+
+    public void setIndex(int index) {
+        this.mIndex = index;
+    }
+
+    public int getIndex() {
+        return this.mIndex;
+    }
+}