day09

model-Note.txt

@@ -0,0 +1,254 @@
+/*
+ * 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.
+ */
+
+import android.content.ContentProviderOperation;//批量的更新、插入、删除数据。
+import android.content.ContentProviderResult;//操作的结果
+import android.content.ContentUris;//用于添加和获取Uri后面的ID
+import android.content.ContentValues;//一种用来存储基本数据类型数据的存储机制
+import android.content.Context;//需要用该类来弄清楚调用者的实例
+import android.content.OperationApplicationException;//操作应用程序容错
+import android.net.Uri;//表示待操作的数据
+import android.os.RemoteException;//远程容错
+import android.util.Log;//输出日志，比如说出错、警告等
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.Notes.TextNote;
+
+import java.util.ArrayList;
+
+
+public class Note {
+    private ContentValues mNoteDiffValues;
+    private NoteData mNoteData;
+    private static final String TAG = "Note";
+    /**
+     * Create a new note id for adding a new note to databases
+     */
+    public static synchronized long getNewNoteId(Context context, long folderId) {
+        // Create a new note in the database
+        ContentValues values = new ContentValues();
+        long createdTime = System.currentTimeMillis();
+        values.put(NoteColumns.CREATED_DATE, createdTime);
+        values.put(NoteColumns.MODIFIED_DATE, createdTime);
+        values.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
+        values.put(NoteColumns.LOCAL_MODIFIED, 1);
+        values.put(NoteColumns.PARENT_ID, folderId);//将数据写入数据库表格
+        Uri uri = context.getContentResolver().insert(Notes.CONTENT_NOTE_URI, values);//ContentResolver()主要是实现外部应用对ContentProvider中的数据
+
+        //实现添加、删除、修改和查询操作
+        long noteId = 0;
+        try {
+            noteId = Long.valueOf(uri.getPathSegments().get(1));
+        } catch (NumberFormatException e) {
+            Log.e(TAG, "Get note id error :" + e.toString());
+            noteId = 0;
+        }//异常处理
+        if (noteId == -1) {
+            throw new IllegalStateException("Wrong note id:" + noteId);
+        }
+        return noteId;
+    }
+
+    public Note() {
+        mNoteDiffValues = new ContentValues();
+        mNoteData = new NoteData();
+    }//定义两个变量用来存储便签的数据，一个是存储便签属性、一个是存储便签内容
+
+    public void setNoteValue(String key, String value) {
+        mNoteDiffValues.put(key, value);
+        mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+        mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+    }//设置数据库表格的标签属性数据
+
+    public void setTextData(String key, String value) {
+        mNoteData.setTextData(key, value);
+    }//设置数据库表格的标签文本内容的数据
+
+    public void setTextDataId(long id) {
+        mNoteData.setTextDataId(id);
+    }//设置文本数据的ID
+
+    public long getTextDataId() {
+        return mNoteData.mTextDataId;
+    }//得到文本数据的ID
+
+    public void setCallDataId(long id) {
+        mNoteData.setCallDataId(id);
+    }//设置电话号码数据的ID
+
+    public void setCallData(String key, String value) {
+        mNoteData.setCallData(key, value);
+    }//得到电话号码数据的ID
+
+    public boolean isLocalModified() {
+        return mNoteDiffValues.size() > 0 || mNoteData.isLocalModified();
+    }//判断是否是本地修改
+
+    public boolean syncNote(Context context, long noteId) {
+        if (noteId <= 0) {
+            throw new IllegalArgumentException("Wrong note id:" + noteId);
+        }
+
+        if (!isLocalModified()) {
+            return true;
+        }
+
+        /**
+         * In theory, once data changed, the note should be updated on {@link NoteColumns#LOCAL_MODIFIED} and
+         * {@link NoteColumns#MODIFIED_DATE}. For data safety, though update note fails, we also update the
+         * note data info
+         */
+        if (context.getContentResolver().update(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), mNoteDiffValues, null,
+                null) == 0) {
+            Log.e(TAG, "Update note error, should not happen");
+            // Do not return, fall through
+        }
+        mNoteDiffValues.clear();
+
+        if (mNoteData.isLocalModified()
+                && (mNoteData.pushIntoContentResolver(context, noteId) == null)) {
+            return false;
+        }
+
+        return true;
+    }//判断数据是否同步
+
+    //定义一个基本的便签内容的数据类，包含文本数据和电话号码数据
+    private class NoteData {
+        private long mTextDataId;
+
+        private ContentValues mTextDataValues;//文本数据
+
+        private long mCallDataId;
+
+        private ContentValues mCallDataValues;//电话号码数据
+
+        private static final String TAG = "NoteData";
+
+        public NoteData() {
+            mTextDataValues = new ContentValues();
+            mCallDataValues = new ContentValues();
+            mTextDataId = 0;
+            mCallDataId = 0;
+        }
+        //函数的具体实现
+        boolean isLocalModified() {
+            return mTextDataValues.size() > 0 || mCallDataValues.size() > 0;
+        }
+
+        void setTextDataId(long id) {
+            if(id <= 0) {
+                throw new IllegalArgumentException("Text data id should larger than 0");
+            }
+            mTextDataId = id;
+        }
+
+        void setCallDataId(long id) {
+            if (id <= 0) {
+                throw new IllegalArgumentException("Call data id should larger than 0");
+            }
+            mCallDataId = id;
+        }
+
+        void setCallData(String key, String value) {
+            mCallDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+
+        void setTextData(String key, String value) {
+            mTextDataValues.put(key, value);
+            mNoteDiffValues.put(NoteColumns.LOCAL_MODIFIED, 1);
+            mNoteDiffValues.put(NoteColumns.MODIFIED_DATE, System.currentTimeMillis());
+        }
+	//下面函数的作用是将新的数据通过Uri的操作存储到数据库
+        Uri pushIntoContentResolver(Context context, long noteId) {
+            /**
+             * Check for safety
+             */
+            if (noteId <= 0) {
+                throw new IllegalArgumentException("Wrong note id:" + noteId);
+            }//判断数据是否合法
+
+            ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+	    //数据库的操作列表
+            ContentProviderOperation.Builder builder = null;
+            if(mTextDataValues.size() > 0) {
+                mTextDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mTextDataId == 0) {
+                    mTextDataValues.put(DataColumns.MIME_TYPE, TextNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mTextDataValues);
+                    try {
+                        setTextDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new text data fail with noteId" + noteId);
+                        mTextDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mTextDataId));
+                    builder.withValues(mTextDataValues);
+                    operationList.add(builder.build());
+                }
+                mTextDataValues.clear();
+            }//把文本数据存入DataColumns
+
+            if(mCallDataValues.size() > 0) {
+                mCallDataValues.put(DataColumns.NOTE_ID, noteId);
+                if (mCallDataId == 0) {
+                    mCallDataValues.put(DataColumns.MIME_TYPE, CallNote.CONTENT_ITEM_TYPE);
+                    Uri uri = context.getContentResolver().insert(Notes.CONTENT_DATA_URI,
+                            mCallDataValues);
+                    try {
+                        setCallDataId(Long.valueOf(uri.getPathSegments().get(1)));
+                    } catch (NumberFormatException e) {
+                        Log.e(TAG, "Insert new call data fail with noteId" + noteId);
+                        mCallDataValues.clear();
+                        return null;
+                    }
+                } else {
+                    builder = ContentProviderOperation.newUpdate(ContentUris.withAppendedId(
+                            Notes.CONTENT_DATA_URI, mCallDataId));
+                    builder.withValues(mCallDataValues);
+                    operationList.add(builder.build());
+                }
+                mCallDataValues.clear();
+            }//把电话号码数据存入DataColumns
+
+            if (operationList.size() > 0) {
+                try {
+                    ContentProviderResult[] results = context.getContentResolver().applyBatch(
+                            Notes.AUTHORITY, operationList);
+                    return (results == null || results.length == 0 || results[0] == null) ? null
+                            : ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId);
+                } catch (RemoteException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                } catch (OperationApplicationException e) {
+                    Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+                    return null;
+                }
+            }//存储过程中的异常处理
+            return null;
+        }
+    }
+}

model-WorkingNote.txt

@@ -0,0 +1,390 @@
+/*
+ * 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.model;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ContentUris;
+import android.content.Context;
+import android.database.Cursor;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+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.Notes.TextNote;
+import net.micode.notes.tool.ResourceParser.NoteBgResources;
+
+
+public class WorkingNote {
+    // Note for the working note
+    private Note mNote;
+    // Note Id
+    private long mNoteId;
+    // Note content
+    private String mContent;
+    // Note mode
+    private int mMode;
+
+    private long mAlertDate;
+
+    private long mModifiedDate;
+
+    private int mBgColorId;
+
+    private int mWidgetId;
+
+    private int mWidgetType;
+
+    private long mFolderId;
+
+    private Context mContext;
+
+    private static final String TAG = "WorkingNote";
+
+    private boolean mIsDeleted;
+
+    private NoteSettingChangedListener mNoteSettingStatusListener;
+    // 声明 DATA_PROJECTION字符串数组
+    public static final String[] DATA_PROJECTION = new String[] {
+            DataColumns.ID,
+            DataColumns.CONTENT,
+            DataColumns.MIME_TYPE,
+            DataColumns.DATA1,
+            DataColumns.DATA2,
+            DataColumns.DATA3,
+            DataColumns.DATA4,
+    };
+    // 声明 NOTE_PROJECTION字符串数组
+    public static final String[] NOTE_PROJECTION = new String[] {
+            NoteColumns.PARENT_ID,
+            NoteColumns.ALERTED_DATE,
+            NoteColumns.BG_COLOR_ID,
+            NoteColumns.WIDGET_ID,
+            NoteColumns.WIDGET_TYPE,
+            NoteColumns.MODIFIED_DATE
+    };
+
+    private static final int DATA_ID_COLUMN = 0;
+
+    private static final int DATA_CONTENT_COLUMN = 1;
+
+    private static final int DATA_MIME_TYPE_COLUMN = 2;
+
+    private static final int DATA_MODE_COLUMN = 3;
+
+    private static final int NOTE_PARENT_ID_COLUMN = 0;
+
+    private static final int NOTE_ALERTED_DATE_COLUMN = 1;
+
+    private static final int NOTE_BG_COLOR_ID_COLUMN = 2;
+
+    private static final int NOTE_WIDGET_ID_COLUMN = 3;
+
+    private static final int NOTE_WIDGET_TYPE_COLUMN = 4;
+
+    private static final int NOTE_MODIFIED_DATE_COLUMN = 5;
+
+    // New note construct
+    private WorkingNote(Context context, long folderId) {
+        mContext = context;
+        mAlertDate = 0;
+        mModifiedDate = System.currentTimeMillis();
+        mFolderId = folderId;
+        mNote = new Note();
+        mNoteId = 0;
+        mIsDeleted = false;
+        mMode = 0;
+        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;
+    }
+
+    // WorkingNote的构造函数
+    // Existing note construct
+    private WorkingNote(Context context, long noteId, long folderId) {
+        mContext = context;
+        mNoteId = noteId;
+        mFolderId = folderId;
+        mIsDeleted = false;
+        mNote = new Note();
+        loadNote();
+    }
+
+    // 加载Note
+    // 通过数据库调用query函数找到第一个条目
+    private void loadNote() {
+        Cursor cursor = mContext.getContentResolver().query(
+                ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mNoteId), NOTE_PROJECTION, null,
+                null, null);
+        //若存在，储存相应信息
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                mFolderId = cursor.getLong(NOTE_PARENT_ID_COLUMN);
+                mBgColorId = cursor.getInt(NOTE_BG_COLOR_ID_COLUMN);
+                mWidgetId = cursor.getInt(NOTE_WIDGET_ID_COLUMN);
+                mWidgetType = cursor.getInt(NOTE_WIDGET_TYPE_COLUMN);
+                mAlertDate = cursor.getLong(NOTE_ALERTED_DATE_COLUMN);
+                mModifiedDate = cursor.getLong(NOTE_MODIFIED_DATE_COLUMN);
+            }
+            cursor.close();
+        //若不存在，报错
+        } else {
+            Log.e(TAG, "No note with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note with id " + mNoteId);
+        }
+        loadNoteData();
+    }
+
+    //加载NoteData
+    private void loadNoteData() {
+        Cursor cursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI, DATA_PROJECTION,
+                DataColumns.NOTE_ID + "=?", new String[] {
+                    String.valueOf(mNoteId)
+                }, null);
+
+        if (cursor != null) {
+            //查到信息不为空
+            if (cursor.moveToFirst()) {//查看第一项是否存在
+                do {
+                    String type = cursor.getString(DATA_MIME_TYPE_COLUMN);
+                    if (DataConstants.NOTE.equals(type)) {
+                        mContent = cursor.getString(DATA_CONTENT_COLUMN);
+                        mMode = cursor.getInt(DATA_MODE_COLUMN);
+                        mNote.setTextDataId(cursor.getLong(DATA_ID_COLUMN));
+                    } else if (DataConstants.CALL_NOTE.equals(type)) {
+                        mNote.setCallDataId(cursor.getLong(DATA_ID_COLUMN));
+                    } else {
+                        Log.d(TAG, "Wrong note type with type:" + type);
+                    }
+                } while (cursor.moveToNext());//查询所有项，直到为空
+            }
+            cursor.close();
+        } else {
+            Log.e(TAG, "No data with id:" + mNoteId);
+            throw new IllegalArgumentException("Unable to find note's data with id " + mNoteId);
+        }
+    }
+    //创建空的Note
+    //传参：context,文件夹id,widget,背景颜色
+    public static WorkingNote createEmptyNote(Context context, long folderId, int widgetId,
+            int widgetType, int defaultBgColorId) {
+        WorkingNote note = new WorkingNote(context, folderId);
+        //设定相关属性
+        note.setBgColorId(defaultBgColorId);
+        note.setWidgetId(widgetId);
+        note.setWidgetType(widgetType);
+        return note;
+    }
+
+    public static WorkingNote load(Context context, long id) {
+        return new WorkingNote(context, id, 0);
+    }
+    //保存Note
+    public synchronized boolean saveNote() {
+        if (isWorthSaving()) {//是否值得保存
+            if (!existInDatabase()) {//是否存在数据库中
+                if ((mNoteId = Note.getNewNoteId(mContext, mFolderId)) == 0) {
+                    Log.e(TAG, "Create new note fail with id:" + mNoteId);
+                    return false;
+                }
+            }
+
+            mNote.syncNote(mContext, mNoteId);
+
+            /**
+             * Update widget content if there exist any widget of this note
+             */
+            if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                    && mWidgetType != Notes.TYPE_WIDGET_INVALIDE
+                    && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();
+            }
+            return true;
+        } else {
+            return false;
+        }
+    }
+    //是否存在数据库中
+    public boolean existInDatabase() {
+        return mNoteId > 0;
+    }
+    //是否值得保存
+    private boolean isWorthSaving() {
+        //被删除，或（不在数据库中 内容为空） ，或本地已经保存过
+        if (mIsDeleted || (!existInDatabase() && TextUtils.isEmpty(mContent))
+                || (existInDatabase() && !mNote.isLocalModified())) {
+            return false;
+        } else {
+            return true;
+        }
+    }
+    //设置mNoteSettingStatuListener
+    public void setOnSettingStatusChangedListener(NoteSettingChangedListener l) {
+        mNoteSettingStatusListener = l;
+    }
+    //设置AlertDate
+    //若mAlertDate与data不同，则更改mAlertDate并设定NoteValue
+    public void setAlertDate(long date, boolean set) {
+        if (date != mAlertDate) {
+            mAlertDate = date;
+            mNote.setNoteValue(NoteColumns.ALERTED_DATE, String.valueOf(mAlertDate));
+        }
+        if (mNoteSettingStatusListener != null) {
+            mNoteSettingStatusListener.onClockAlertChanged(date, set);
+        }
+    }
+    //设定删除标记
+    public void markDeleted(boolean mark) {
+        //设定标记
+        mIsDeleted = mark;
+        if (mWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID
+                && mWidgetType != Notes.TYPE_WIDGET_INVALIDE && mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onWidgetChanged();//调用mNoteSettingStatusListener的 onWidgetChanged方法
+        }
+    }
+    //设定背景颜色
+    public void setBgColorId(int id) {
+        if (id != mBgColorId) {//设定条件id!=mBgColorId
+            mBgColorId = id;
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onBackgroundColorChanged();
+            }
+            mNote.setNoteValue(NoteColumns.BG_COLOR_ID, String.valueOf(id));
+        }
+    }
+    // 设定检查列表模式
+    // 参数：mode
+    public void setCheckListMode(int mode) {
+        if (mMode != mode) {//设定条件
+            if (mNoteSettingStatusListener != null) {
+                mNoteSettingStatusListener.onCheckListModeChanged(mMode, mode);
+            }
+            mMode = mode;
+            mNote.setTextData(TextNote.MODE, String.valueOf(mMode));
+        }
+    }
+    // 设定WidgetType
+    // 参数：type
+    public void setWidgetType(int type) {
+        if (type != mWidgetType) {//设定条件
+            mWidgetType = type;
+            mNote.setNoteValue(NoteColumns.WIDGET_TYPE, String.valueOf(mWidgetType));
+            // 调用Note的setNoteValue方法更改WidgetType
+
+        }
+    }
+    // 设定WidgetId
+    // 参数：id
+    public void setWidgetId(int id) {
+        if (id != mWidgetId) {//设定条件
+            mWidgetId = id;
+            mNote.setNoteValue(NoteColumns.WIDGET_ID, String.valueOf(mWidgetId));
+            // 调用Note的setNoteValue方法更改WidgetId
+        }
+    }
+    // 设定WorkingTex
+    // 参数：更改的text
+    public void setWorkingText(String text) {
+        if (!TextUtils.equals(mContent, text)) {
+            mContent = text;
+            mNote.setTextData(DataColumns.CONTENT, mContent);
+            // 调用Note的setTextData方法更改WorkingText
+        }
+    }
+    // 转变mNote的CallData及CallNote信息
+    // 参数：String phoneNumber, long callDate
+    public void convertToCallNote(String phoneNumber, long callDate) {
+        mNote.setCallData(CallNote.CALL_DATE, String.valueOf(callDate));
+        mNote.setCallData(CallNote.PHONE_NUMBER, phoneNumber);
+        mNote.setNoteValue(NoteColumns.PARENT_ID, String.valueOf(Notes.ID_CALL_RECORD_FOLDER));
+    }
+    //判断是否有时钟题型
+    public boolean hasClockAlert() {
+        return (mAlertDate > 0 ? true : false);
+    }
+    //获取Content
+    public String getContent() {
+        return mContent;
+    }
+    //获取AlertDate
+    public long getAlertDate() {
+        return mAlertDate;
+    }
+    //获取ModifiedDate
+    public long getModifiedDate() {
+        return mModifiedDate;
+    }
+    //获取背景颜色来源id
+    public int getBgColorResId() {
+        return NoteBgResources.getNoteBgResource(mBgColorId);
+    }
+    //获取背景颜色id
+    public int getBgColorId() {
+        return mBgColorId;
+    }
+    //获取标题背景颜色id
+    public int getTitleBgResId() {
+        return NoteBgResources.getNoteTitleBgResource(mBgColorId);
+    }
+    //获取CheckListMode
+    public int getCheckListMode() {
+        return mMode;
+    }
+    //获取便签id
+    public long getNoteId() {
+        return mNoteId;
+    }
+    //获取文件夹id
+    public long getFolderId() {
+        return mFolderId;
+    }
+    //获取WidgetId
+    public int getWidgetId() {
+        return mWidgetId;
+    }
+    //获取WidgetType
+    public int getWidgetType() {
+        return mWidgetType;
+    }
+    // 创建接口 NoteSettingChangedListener,便签更新监视
+    // 为NoteEditActivity提供接口
+    // 提供函数有
+    public interface NoteSettingChangedListener {
+        /**
+         * Called when the background color of current note has just changed
+         */
+        void onBackgroundColorChanged();
+
+        /**
+         * Called when user set clock
+         */
+        void onClockAlertChanged(long date, boolean set);
+
+        /**
+         * Call when user create note from widget
+         */
+        void onWidgetChanged();
+
+        /**
+         * Call when switch between check list mode and normal mode
+         * @param oldMode is previous mode before change
+         * @param newMode is new mode
+         */
+        void onCheckListModeChanged(int oldMode, int newMode);
+    }
+}

tool-BackupUtils.txt

@@ -0,0 +1,349 @@
+/*
+ * 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.tool;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.os.Environment;
+import android.text.TextUtils;
+import android.text.format.DateFormat;
+import android.util.Log;
+
+import net.micode.notes.R;
+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 java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+
+
+public class BackupUtils {
+    private static final String TAG = "BackupUtils";
+    // Singleton stuff
+    private static BackupUtils sInstance;//类里面为什么可以定义自身类对象?
+    //ynchronized 关键字，代表这个方法加锁,相当于不管哪一个线程（例如线程A）
+    //运行到这个方法时,都要检查有没有其它线程B（或者C、 D等）正在用这个方法(或者该类的其他同步方法)，有的话要等正在使用synchronized方法的线程B（或者C 、D）运行完这个方法后再运行此线程A,没有的话,锁定调用者,然后直接运行。
+    //它包括两种用法：synchronized 方法和 synchronized 块。
+    public static synchronized BackupUtils getInstance(Context context) {
+        if (sInstance == null) {
+            //如果当前备份不存在，则新声明一个
+            sInstance = new BackupUtils(context);
+        }
+        return sInstance;
+    }
+
+    /**
+     * Following states are signs to represents backup or restore
+     * status
+     */
+    // Currently, the sdcard is not mounted  SD卡没有被装入手机
+    public static final int STATE_SD_CARD_UNMOUONTED           = 0;
+    // The backup file not exist    备份文件夹不存在
+    public static final int STATE_BACKUP_FILE_NOT_EXIST        = 1;
+    // The data is not well formated, may be changed by other programs     数据已被破坏
+    public static final int STATE_DATA_DESTROIED               = 2;
+    // Some run-time exception which causes restore or backup fails     超时异常
+    public static final int STATE_SYSTEM_ERROR                 = 3;
+    // Backup or restore success    成功存储
+    public static final int STATE_SUCCESS                      = 4;
+
+    private TextExport mTextExport;
+    //初始化函数
+    private BackupUtils(Context context) {
+        mTextExport = new TextExport(context);
+    }
+    //外部储存功能是否可用
+    private static boolean externalStorageAvailable() {
+        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
+    }
+
+    public int exportToText() {
+        return mTextExport.exportToText();
+    }
+
+    public String getExportedTextFileName() {
+        return mTextExport.mFileName;
+    }
+
+    public String getExportedTextFileDir() {
+        return mTextExport.mFileDirectory;
+    }
+
+    private static class TextExport {
+        private static final String[] NOTE_PROJECTION = {
+                NoteColumns.ID,
+                NoteColumns.MODIFIED_DATE,
+                NoteColumns.SNIPPET,
+                NoteColumns.TYPE
+        };
+
+        private static final int NOTE_COLUMN_ID = 0;
+
+        private static final int NOTE_COLUMN_MODIFIED_DATE = 1;
+
+        private static final int NOTE_COLUMN_SNIPPET = 2;
+
+        private static final String[] DATA_PROJECTION = {
+                DataColumns.CONTENT,
+                DataColumns.MIME_TYPE,
+                DataColumns.DATA1,
+                DataColumns.DATA2,
+                DataColumns.DATA3,
+                DataColumns.DATA4,
+        };
+
+        private static final int DATA_COLUMN_CONTENT = 0;
+
+        private static final int DATA_COLUMN_MIME_TYPE = 1;
+
+        private static final int DATA_COLUMN_CALL_DATE = 2;
+
+        private static final int DATA_COLUMN_PHONE_NUMBER = 4;
+
+        private final String [] TEXT_FORMAT;
+        private static final int FORMAT_FOLDER_NAME          = 0;
+        private static final int FORMAT_NOTE_DATE            = 1;
+        private static final int FORMAT_NOTE_CONTENT         = 2;
+
+        private Context mContext;
+        private String mFileName;
+        private String mFileDirectory;
+
+        public TextExport(Context context) {
+            TEXT_FORMAT = context.getResources().getStringArray(R.array.format_for_exported_note);
+            mContext = context;
+            mFileName = "";
+            mFileDirectory = "";
+        }
+        //获取文本的组成部分
+        private String getFormat(int id) {
+            return TEXT_FORMAT[id];
+        }
+
+        /**
+         * Export the folder identified by folder id to text
+         */
+        private void exportFolderToText(String folderId, PrintStream ps) {
+            // Query notes belong to this folder  通过查询parent id是文件夹id的note来选出制定ID文件夹下的Note
+            Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION, NoteColumns.PARENT_ID + "=?", new String[] {
+                        folderId
+                    }, null);
+
+            if (notesCursor != null) {
+                if (notesCursor.moveToFirst()) {
+                    do {
+                        // Print note's last modified date   ps里面保存有这份note的日期
+                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
+                                mContext.getString(R.string.format_datetime_mdhm),
+                                notesCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
+                        // Query data belong to this note
+                        String noteId = notesCursor.getString(NOTE_COLUMN_ID);
+                        exportNoteToText(noteId, ps);
+                    } while (notesCursor.moveToNext());//将文件导出到text
+                }
+                notesCursor.close();
+            }
+        }
+
+        /**
+         * Export note identified by id to a print stream
+         */
+        private void exportNoteToText(String noteId, PrintStream ps) {
+            Cursor dataCursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI,
+                    DATA_PROJECTION, DataColumns.NOTE_ID + "=?", new String[] {
+                        noteId
+                    }, null);
+            //利用光标来扫描内容，区别为callnote和note两种，靠ps.printline输出
+            if (dataCursor != null) {
+                if (dataCursor.moveToFirst()) {
+                    do {
+                        String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);
+                        if (DataConstants.CALL_NOTE.equals(mimeType)) {
+                            // Print phone number
+                            String phoneNumber = dataCursor.getString(DATA_COLUMN_PHONE_NUMBER);
+                            long callDate = dataCursor.getLong(DATA_COLUMN_CALL_DATE);
+                            String location = dataCursor.getString(DATA_COLUMN_CONTENT);
+                            //判断是否为空字符
+                            if (!TextUtils.isEmpty(phoneNumber)) {
+                                ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
+                                        phoneNumber));
+                            }
+                            // Print call date
+                            ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT), DateFormat
+                                    .format(mContext.getString(R.string.format_datetime_mdhm),
+                                            callDate)));
+                            // Print call attachment location
+                            if (!TextUtils.isEmpty(location)) {
+                                ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
+                                        location));
+                            }
+                        } else if (DataConstants.NOTE.equals(mimeType)) {
+                            String content = dataCursor.getString(DATA_COLUMN_CONTENT);
+                            if (!TextUtils.isEmpty(content)) {
+                                ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
+                                        content));
+                            }
+                        }
+                    } while (dataCursor.moveToNext());
+                }
+                dataCursor.close();
+            }
+            // print a line separator between note
+            try {
+                ps.write(new byte[] {
+                        Character.LINE_SEPARATOR, Character.LETTER_NUMBER
+                });
+            } catch (IOException e) {
+                Log.e(TAG, e.toString());
+            }
+        }
+
+        /**
+         * Note will be exported as text which is user readable
+         */
+        //总函数，调用上面的exportFolder和exportNote
+        public int exportToText() {
+            if (!externalStorageAvailable()) {
+                Log.d(TAG, "Media was not mounted");
+                return STATE_SD_CARD_UNMOUONTED;
+            }
+
+            PrintStream ps = getExportToTextPrintStream();
+            if (ps == null) {
+                Log.e(TAG, "get print stream error");
+                return STATE_SYSTEM_ERROR;
+            }
+            // First export folder and its notes     导出文件夹，就是导出里面包含的便签
+            Cursor folderCursor = mContext.getContentResolver().query(
+                    Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION,
+                    "(" + NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER + " AND "
+                            + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER + ") OR "
+                            + NoteColumns.ID + "=" + Notes.ID_CALL_RECORD_FOLDER, null, null);
+
+            if (folderCursor != null) {
+                if (folderCursor.moveToFirst()) {
+                    do {
+                        // Print folder's name
+                        String folderName = "";
+                        if(folderCursor.getLong(NOTE_COLUMN_ID) == Notes.ID_CALL_RECORD_FOLDER) {
+                            folderName = mContext.getString(R.string.call_record_folder_name);
+                        } else {
+                            folderName = folderCursor.getString(NOTE_COLUMN_SNIPPET);
+                        }
+                        if (!TextUtils.isEmpty(folderName)) {
+                            ps.println(String.format(getFormat(FORMAT_FOLDER_NAME), folderName));
+                        }
+                        String folderId = folderCursor.getString(NOTE_COLUMN_ID);
+                        exportFolderToText(folderId, ps);
+                    } while (folderCursor.moveToNext());
+                }
+                folderCursor.close();
+            }
+
+            // Export notes in root's folder     将根目录里的便签导出（由于不属于任何文件夹，因此无法通过文件夹导出来实现这一部分便签的导出）
+            Cursor noteCursor = mContext.getContentResolver().query(
+                    Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION,
+                    NoteColumns.TYPE + "=" + +Notes.TYPE_NOTE + " AND " + NoteColumns.PARENT_ID
+                            + "=0", null, null);
+
+            if (noteCursor != null) {
+                if (noteCursor.moveToFirst()) {
+                    do {
+                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
+                                mContext.getString(R.string.format_datetime_mdhm),
+                                noteCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
+                        // Query data belong to this note
+                        String noteId = noteCursor.getString(NOTE_COLUMN_ID);
+                        exportNoteToText(noteId, ps);
+                    } while (noteCursor.moveToNext());
+                }
+                noteCursor.close();
+            }
+            ps.close();
+
+            return STATE_SUCCESS;
+        }
+
+        /**
+         * Get a print stream pointed to the file {@generateExportedTextFile}
+         */
+        private PrintStream getExportToTextPrintStream() {
+            File file = generateFileMountedOnSDcard(mContext, R.string.file_path,
+                    R.string.file_name_txt_format);
+            if (file == null) {
+                Log.e(TAG, "create file to exported failed");
+                return null;
+            }
+            mFileName = file.getName();
+            mFileDirectory = mContext.getString(R.string.file_path);
+            PrintStream ps = null;
+            try {
+                FileOutputStream fos = new FileOutputStream(file);
+                //将ps输出流输出到特定的文件，目的就是导出到文件，而不是直接输出
+                ps = new PrintStream(fos);
+            } catch (FileNotFoundException e) {
+                e.printStackTrace();
+                return null;
+            } catch (NullPointerException e) {
+                e.printStackTrace();
+                return null;
+            }
+            return ps;
+        }
+    }
+
+    /**
+     * Generate the text file to store imported data
+     */
+    private static File generateFileMountedOnSDcard(Context context, int filePathResId, int fileNameFormatResId) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(Environment.getExternalStorageDirectory());  //外部（SD卡）的存储路径
+        sb.append(context.getString(filePathResId));    //文件的存储路径
+        File filedir = new File(sb.toString());        //filedir应该就是用来存储路径信息
+        sb.append(context.getString(
+                fileNameFormatResId,
+                DateFormat.format(context.getString(R.string.format_date_ymd),
+                        System.currentTimeMillis())));
+        File file = new File(sb.toString());
+        //如果这些文件不存在，则新建
+        try {
+            if (!filedir.exists()) {
+                filedir.mkdir();
+            }
+            if (!file.exists()) {
+                file.createNewFile();
+            }
+            return file;
+        } catch (SecurityException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        // try catch 异常处理
+        return null;
+    }
+}
+
+

tool-DataUtils.txt

@@ -0,0 +1,297 @@
+/*
+ * 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.tool;
+
+import android.content.ContentProviderOperation;
+import android.content.ContentProviderResult;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.OperationApplicationException;
+import android.database.Cursor;
+import android.os.RemoteException;
+import android.util.Log;
+
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.CallNote;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.ui.NotesListAdapter.AppWidgetAttribute;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+
+
+public class DataUtils {
+    public static final String TAG = "DataUtils";
+    public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {
+        if (ids == null) {
+            Log.d(TAG, "the ids is null");
+            return true;
+        }
+        if (ids.size() == 0) {
+            Log.d(TAG, "no id is in the hashset");
+            return true;
+        }
+
+        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+        for (long id : ids) {
+            if(id == Notes.ID_ROOT_FOLDER) {
+                Log.e(TAG, "Don't delete system folder root");
+                continue;
+            }  //如果发现是根文件夹，则不删除
+            ContentProviderOperation.Builder builder = ContentProviderOperation
+                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+            operationList.add(builder.build());
+        }//将ids里包含的每一列的数据逐次加入到operationList中，等待最后的批量处理
+        try {
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            //数据库事务，数据库事务是由一组数据库操作序列组成，事务作为一个整体被执行
+            if (results == null || results.length == 0 || results[0] == null) {
+                Log.d(TAG, "delete notes failed, ids:" + ids.toString());
+                return false;
+            }
+            return true;
+        } catch (RemoteException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        } catch (OperationApplicationException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        }
+        return false;
+    }
+
+    public static void moveNoteToFoler(ContentResolver resolver, long id, long srcFolderId, long desFolderId) {
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.PARENT_ID, desFolderId);
+        values.put(NoteColumns.ORIGIN_PARENT_ID, srcFolderId);
+        values.put(NoteColumns.LOCAL_MODIFIED, 1);
+        resolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id), values, null, null);
+    }
+
+    public static boolean batchMoveToFolder(ContentResolver resolver, HashSet<Long> ids,
+            long folderId) {
+        if (ids == null) {
+            Log.d(TAG, "the ids is null");
+            return true;
+        }
+
+        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+        for (long id : ids) {
+            ContentProviderOperation.Builder builder = ContentProviderOperation
+                    .newUpdate(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+            builder.withValue(NoteColumns.PARENT_ID, folderId);
+            builder.withValue(NoteColumns.LOCAL_MODIFIED, 1);
+            operationList.add(builder.build());
+        }
+
+        try {
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            if (results == null || results.length == 0 || results[0] == null) {
+                Log.d(TAG, "delete notes failed, ids:" + ids.toString());
+                return false;
+            }
+            return true;
+        } catch (RemoteException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        } catch (OperationApplicationException e) {
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        }
+        return false;
+    }
+
+    /**
+     * Get the all folder count except system folders {@link Notes#TYPE_SYSTEM}}
+     */
+    public static int getUserFolderCount(ContentResolver resolver) {
+        Cursor cursor =resolver.query(Notes.CONTENT_NOTE_URI,
+                new String[] { "COUNT(*)" },
+                NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>?",
+                new String[] { String.valueOf(Notes.TYPE_FOLDER), String.valueOf(Notes.ID_TRASH_FOLER)},
+                null);//筛选条件：源文件不为trash folder
+
+        int count = 0;
+        if(cursor != null) {
+            if(cursor.moveToFirst()) {
+                try {
+                    count = cursor.getInt(0);
+                } catch (IndexOutOfBoundsException e) {
+                    Log.e(TAG, "get folder count failed:" + e.toString());
+                } finally {
+                    cursor.close();
+                }
+            }
+        }
+        return count;
+    }
+
+    public static boolean visibleInNoteDatabase(ContentResolver resolver, long noteId, int type) {
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
+                null,
+                NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER,
+                new String [] {String.valueOf(type)},
+                null);//查询条件：type符合，且不属于垃圾文件夹
+
+        boolean exist = false;
+        if (cursor != null) {
+            if (cursor.getCount() > 0) {//用getcount函数判断cursor是否为空
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static boolean existInNoteDatabase(ContentResolver resolver, long noteId) {
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
+                null, null, null, null);
+
+        boolean exist = false;
+        if (cursor != null) {
+            if (cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static boolean existInDataDatabase(ContentResolver resolver, long dataId) {
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId),
+                null, null, null, null);
+
+        boolean exist = false;
+        if (cursor != null) {
+            if (cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static boolean checkVisibleFolderName(ContentResolver resolver, String name) {
+        Cursor cursor = resolver.query(Notes.CONTENT_NOTE_URI, null,
+                NoteColumns.TYPE + "=" + Notes.TYPE_FOLDER +
+                " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER +
+                " AND " + NoteColumns.SNIPPET + "=?",
+                new String[] { name }, null);
+        //通过名字查询文件是否存在
+        boolean exist = false;
+        if(cursor != null) {
+            if(cursor.getCount() > 0) {
+                exist = true;
+            }
+            cursor.close();
+        }
+        return exist;
+    }
+
+    public static HashSet<AppWidgetAttribute> getFolderNoteWidget(ContentResolver resolver, long folderId) {
+        Cursor c = resolver.query(Notes.CONTENT_NOTE_URI,
+                new String[] { NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE },
+                NoteColumns.PARENT_ID + "=?",
+                new String[] { String.valueOf(folderId) },
+                null);//查询条件：父ID是传入的folderId;
+
+        HashSet<AppWidgetAttribute> set = null;
+        if (c != null) {
+            if (c.moveToFirst()) {
+                set = new HashSet<AppWidgetAttribute>();
+                do {
+                    try {
+                        AppWidgetAttribute widget = new AppWidgetAttribute();
+                        widget.widgetId = c.getInt(0);//0对应的NoteColumns.WIDGET_ID
+                        widget.widgetType = c.getInt(1);//1对应的NoteColumns.WIDGET_TYPE
+                        set.add(widget);
+                    } catch (IndexOutOfBoundsException e) {
+                        Log.e(TAG, e.toString());
+                    }
+                } while (c.moveToNext()); //查询下一条
+            }
+            c.close();
+        }
+        return set;
+    }
+
+    public static String getCallNumberByNoteId(ContentResolver resolver, long noteId) {
+        Cursor cursor = resolver.query(Notes.CONTENT_DATA_URI,
+                new String [] { CallNote.PHONE_NUMBER },
+                CallNote.NOTE_ID + "=? AND " + CallNote.MIME_TYPE + "=?",
+                new String [] { String.valueOf(noteId), CallNote.CONTENT_ITEM_TYPE },
+                null);
+
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                return cursor.getString(0);
+            } catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, "Get call number fails " + e.toString());
+            } finally {
+                cursor.close();
+            }
+        }
+        return "";
+    }
+
+    public static long getNoteIdByPhoneNumberAndCallDate(ContentResolver resolver, String phoneNumber, long callDate) {
+        Cursor cursor = resolver.query(Notes.CONTENT_DATA_URI,
+                new String [] { CallNote.NOTE_ID },
+                CallNote.CALL_DATE + "=? AND " + CallNote.MIME_TYPE + "=? AND PHONE_NUMBERS_EQUAL("
+                + CallNote.PHONE_NUMBER + ",?)",
+                new String [] { String.valueOf(callDate), CallNote.CONTENT_ITEM_TYPE, phoneNumber },
+                null);//通过数据库操作，查询条件是（callDate和phoneNumber匹配传入参数的值）
+
+        if (cursor != null) {
+            if (cursor.moveToFirst()) {
+                try {
+                    return cursor.getLong(0);//0对应的CallNote.NOTE_ID
+                } catch (IndexOutOfBoundsException e) {
+                    Log.e(TAG, "Get call note id fails " + e.toString());
+                }
+            }
+            cursor.close();
+        }
+        return 0;
+    }
+
+    public static String getSnippetById(ContentResolver resolver, long noteId) {
+        Cursor cursor = resolver.query(Notes.CONTENT_NOTE_URI,
+                new String [] { NoteColumns.SNIPPET },
+                NoteColumns.ID + "=?",
+                new String [] { String.valueOf(noteId)},
+                null);//查询条件：noteId
+
+        if (cursor != null) {
+            String snippet = "";
+            if (cursor.moveToFirst()) {
+                snippet = cursor.getString(0);
+            }
+            cursor.close();
+            return snippet;
+        }
+        throw new IllegalArgumentException("Note is not found with id: " + noteId);
+    }
+
+    public static String getFormattedSnippet(String snippet) {//对字符串进行格式处理，将字符串两头的空格去掉，同时将换行符去掉
+        if (snippet != null) {
+            snippet = snippet.trim();
+            int index = snippet.indexOf('\n');
+            if (index != -1) {
+                snippet = snippet.substring(0, index);
+            }
+        }
+        return snippet;
+    }
+}

tool-GTaskStringUtils.txt

@@ -0,0 +1,113 @@
+/*
+ * 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.
+ */
+//简介：定义了很多的静态字符串，目的就是为了提供jsonObject中相应字符串的"key"。把这些静态的定义单独写到了一个类里面，这是非常好的编程规范
+package net.micode.notes.tool;
+//这个类就是定义了一堆static string，实际就是为jsonObject提供Key，把这些定义全部写到一个类里，方便查看管理，是一个非常好的编程习惯
+public class GTaskStringUtils {
+
+    public final static String GTASK_JSON_ACTION_ID = "action_id";
+
+    public final static String GTASK_JSON_ACTION_LIST = "action_list";
+
+    public final static String GTASK_JSON_ACTION_TYPE = "action_type";
+
+    public final static String GTASK_JSON_ACTION_TYPE_CREATE = "create";
+
+    public final static String GTASK_JSON_ACTION_TYPE_GETALL = "get_all";
+
+    public final static String GTASK_JSON_ACTION_TYPE_MOVE = "move";
+
+    public final static String GTASK_JSON_ACTION_TYPE_UPDATE = "update";
+
+    public final static String GTASK_JSON_CREATOR_ID = "creator_id";
+
+    public final static String GTASK_JSON_CHILD_ENTITY = "child_entity";
+
+    public final static String GTASK_JSON_CLIENT_VERSION = "client_version";
+
+    public final static String GTASK_JSON_COMPLETED = "completed";
+
+    public final static String GTASK_JSON_CURRENT_LIST_ID = "current_list_id";
+
+    public final static String GTASK_JSON_DEFAULT_LIST_ID = "default_list_id";
+
+    public final static String GTASK_JSON_DELETED = "deleted";
+
+    public final static String GTASK_JSON_DEST_LIST = "dest_list";
+
+    public final static String GTASK_JSON_DEST_PARENT = "dest_parent";
+
+    public final static String GTASK_JSON_DEST_PARENT_TYPE = "dest_parent_type";
+
+    public final static String GTASK_JSON_ENTITY_DELTA = "entity_delta";
+
+    public final static String GTASK_JSON_ENTITY_TYPE = "entity_type";
+
+    public final static String GTASK_JSON_GET_DELETED = "get_deleted";
+
+    public final static String GTASK_JSON_ID = "id";
+
+    public final static String GTASK_JSON_INDEX = "index";
+
+    public final static String GTASK_JSON_LAST_MODIFIED = "last_modified";
+
+    public final static String GTASK_JSON_LATEST_SYNC_POINT = "latest_sync_point";
+
+    public final static String GTASK_JSON_LIST_ID = "list_id";
+
+    public final static String GTASK_JSON_LISTS = "lists";
+
+    public final static String GTASK_JSON_NAME = "name";
+
+    public final static String GTASK_JSON_NEW_ID = "new_id";
+
+    public final static String GTASK_JSON_NOTES = "notes";
+
+    public final static String GTASK_JSON_PARENT_ID = "parent_id";
+
+    public final static String GTASK_JSON_PRIOR_SIBLING_ID = "prior_sibling_id";
+
+    public final static String GTASK_JSON_RESULTS = "results";
+
+    public final static String GTASK_JSON_SOURCE_LIST = "source_list";
+
+    public final static String GTASK_JSON_TASKS = "tasks";
+
+    public final static String GTASK_JSON_TYPE = "type";
+
+    public final static String GTASK_JSON_TYPE_GROUP = "GROUP";
+
+    public final static String GTASK_JSON_TYPE_TASK = "TASK";
+
+    public final static String GTASK_JSON_USER = "user";
+
+    public final static String MIUI_FOLDER_PREFFIX = "[MIUI_Notes]";
+
+    public final static String FOLDER_DEFAULT = "Default";
+
+    public final static String FOLDER_CALL_NOTE = "Call_Note";
+
+    public final static String FOLDER_META = "METADATA";
+
+    public final static String META_HEAD_GTASK_ID = "meta_gid";
+
+    public final static String META_HEAD_NOTE = "meta_note";
+
+    public final static String META_HEAD_DATA = "meta_data";
+
+    public final static String META_NOTE_NAME = "[META INFO] DON'T UPDATE AND DELETE";
+
+}

tool-ResourceParser.txt

@@ -0,0 +1,195 @@
+/*
+ * 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.tool;
+
+/*简介：字面意义是资源分析器，实际上就是获取资源并且在程序中使用，比如颜色图片等
+ * 实现方法：主要利用R.java这个类，其中包括
+ * R.id      组件资源引用
+ * R.drawable  图片资源 （被使用）
+ * R.layout  布局资源
+ * R.menu   菜单资源
+ * R.String  文字资源
+ * R.style    主题资源 （被使用）
+ * 在按顺序设置好相应的id后，就可以编写简单的getXXX函数获取需要的资源
+ *
+ * 特殊的变量 ：
+ * @BG_DEFAULT_COLOR 默认背景颜色（黄）
+ * BG_DEFAULT_FONT_SIZE 默认文本大小（中）
+ */
+import android.content.Context;
+import android.preference.PreferenceManager;
+
+import net.micode.notes.R;
+import net.micode.notes.ui.NotesPreferenceActivity;
+
+public class ResourceParser {
+
+    public static final int YELLOW           = 0;
+    public static final int BLUE             = 1;
+    public static final int WHITE            = 2;
+    public static final int GREEN            = 3;
+    public static final int RED              = 4;
+
+    public static final int BG_DEFAULT_COLOR = YELLOW;
+
+    public static final int TEXT_SMALL       = 0;
+    public static final int TEXT_MEDIUM      = 1;
+    public static final int TEXT_LARGE       = 2;
+    public static final int TEXT_SUPER       = 3;
+
+    public static final int BG_DEFAULT_FONT_SIZE = TEXT_MEDIUM;
+
+    public static class NoteBgResources {
+        private final static int [] BG_EDIT_RESOURCES = new int [] {
+            R.drawable.edit_yellow,
+            R.drawable.edit_blue,
+            R.drawable.edit_white,
+            R.drawable.edit_green,
+            R.drawable.edit_red
+        };
+
+        private final static int [] BG_EDIT_TITLE_RESOURCES = new int [] {
+            R.drawable.edit_title_yellow,
+            R.drawable.edit_title_blue,
+            R.drawable.edit_title_white,
+            R.drawable.edit_title_green,
+            R.drawable.edit_title_red
+        };
+
+        public static int getNoteBgResource(int id) {
+            return BG_EDIT_RESOURCES[id];
+        }
+
+        public static int getNoteTitleBgResource(int id) {
+            return BG_EDIT_TITLE_RESOURCES[id];
+        }
+    }
+    //直接获取默认的背景颜色。
+    public static int getDefaultBgId(Context context) {
+        if (PreferenceManager.getDefaultSharedPreferences(context).getBoolean(
+                NotesPreferenceActivity.PREFERENCE_SET_BG_COLOR_KEY, false)) {
+            return (int) (Math.random() * NoteBgResources.BG_EDIT_RESOURCES.length);
+        } else {
+            return BG_DEFAULT_COLOR;
+        }
+    }
+
+    public static class NoteItemBgResources {
+        private final static int [] BG_FIRST_RESOURCES = new int [] {
+            R.drawable.list_yellow_up,
+            R.drawable.list_blue_up,
+            R.drawable.list_white_up,
+            R.drawable.list_green_up,
+            R.drawable.list_red_up
+        };
+
+        private final static int [] BG_NORMAL_RESOURCES = new int [] {
+            R.drawable.list_yellow_middle,
+            R.drawable.list_blue_middle,
+            R.drawable.list_white_middle,
+            R.drawable.list_green_middle,
+            R.drawable.list_red_middle
+        };
+
+        private final static int [] BG_LAST_RESOURCES = new int [] {
+            R.drawable.list_yellow_down,
+            R.drawable.list_blue_down,
+            R.drawable.list_white_down,
+            R.drawable.list_green_down,
+            R.drawable.list_red_down,
+        };
+
+        private final static int [] BG_SINGLE_RESOURCES = new int [] {
+            R.drawable.list_yellow_single,
+            R.drawable.list_blue_single,
+            R.drawable.list_white_single,
+            R.drawable.list_green_single,
+            R.drawable.list_red_single
+        };
+
+        public static int getNoteBgFirstRes(int id) {
+            return BG_FIRST_RESOURCES[id];
+        }
+
+        public static int getNoteBgLastRes(int id) {
+            return BG_LAST_RESOURCES[id];
+        }
+
+        public static int getNoteBgSingleRes(int id) {
+            return BG_SINGLE_RESOURCES[id];
+        }
+
+        public static int getNoteBgNormalRes(int id) {
+            return BG_NORMAL_RESOURCES[id];
+        }
+
+        public static int getFolderBgRes() {
+            return R.drawable.list_folder;
+        }
+    }
+
+    public static class WidgetBgResources {
+        private final static int [] BG_2X_RESOURCES = new int [] {
+            R.drawable.widget_2x_yellow,
+            R.drawable.widget_2x_blue,
+            R.drawable.widget_2x_white,
+            R.drawable.widget_2x_green,
+            R.drawable.widget_2x_red,
+        };
+
+        public static int getWidget2xBgResource(int id) {
+            return BG_2X_RESOURCES[id];
+        }
+
+        private final static int [] BG_4X_RESOURCES = new int [] {
+            R.drawable.widget_4x_yellow,
+            R.drawable.widget_4x_blue,
+            R.drawable.widget_4x_white,
+            R.drawable.widget_4x_green,
+            R.drawable.widget_4x_red
+        };
+
+        public static int getWidget4xBgResource(int id) {
+            return BG_4X_RESOURCES[id];
+        }
+    }
+
+    public static class TextAppearanceResources {
+        private final static int [] TEXTAPPEARANCE_RESOURCES = new int [] {
+            R.style.TextAppearanceNormal,
+            R.style.TextAppearanceMedium,
+            R.style.TextAppearanceLarge,
+            R.style.TextAppearanceSuper
+        };
+        //这里有一个容错的函数，防止输入的id大于资源总量，若如此，则自动返回默认的设置结果
+        public static int getTexAppearanceResource(int id) {
+            /**
+             * HACKME: Fix bug of store the resource id in shared preference.
+             * The id may larger than the length of resources, in this case,
+             * return the {@link ResourceParser#BG_DEFAULT_FONT_SIZE}
+             */
+            if (id >= TEXTAPPEARANCE_RESOURCES.length) {
+                return BG_DEFAULT_FONT_SIZE;
+            }
+            return TEXTAPPEARANCE_RESOURCES[id];
+        }
+
+        public static int getResourcesSize() {
+            return TEXTAPPEARANCE_RESOURCES.length;
+        }
+    }
+}