android实现本程序数据的备份与恢复

本文原创，转载爬虫请保留原文地址：http://maosidiaoxian.iteye.com/blog/1488067 

android中数据存储方式主要有四种，即SharePreferences,Sqlite3,文件和ContentProvider。所以要对本程序的数据进行备份，其实也就是把这些数据文件拷贝到另外的目录，在恢复时再拷贝回来。 
以下以我的一个程序为例，其中使用了SharePreferences及sqlite3两个数据存储的方法。在备份时将其拷到SD卡，恢复时再拷贝回来。由于对文件流的操作在这里不是我应该关注的地方，于是直接用了apache开源项目commons中的IO包里的FileUtils类的方法。 
在使用过程中，发现直接复制到手机中结果是操作失败，不知道是不是我权限没有添加上。不过复制到SD卡上却是成功的。 
下面的ApkInfo及ResourceUtil是我自己封装的，顾名思义，里面包含程序的图标、包名、程序名等等一系列信息，所在的包放在了google code（http://code.google.com/p/cfuture-androidkit/）有sourceforge（http://sourceforge.net/projects/cf-androidkit/files/）中。 
备份与恢复的代码如下： 

 /*
  * @(#)Backup.java             Project:UniversityTimetable
  * Date:2012-4-16
  *
  * Copyright (c) 2011 CFuture09, Institute of Software,
  * Guangdong Ocean University, Zhanjiang, GuangDong, China.
  * All rights reserved.
  *
  * 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 com.lurencun.cfuture09.universityTimetable.backup.util;

 import java.io.File;
 import java.io.IOException;

 import org.apache.commons.io.FileUtils;

 import android.content.Context;
 import android.os.Environment;
 import android.widget.Toast;

 import com.sinaapp.msdxblog.androidkit.util.ResourceUtil;
 import com.sinaapp.msdxblog.androidkit.util.entity.ApkInfo;

 /**
  * @author Geek_Soledad ([email protected])
  */
 public class Backup {

     private String SHARED_PREFS;
     private String DATABASES;
     private String APP_PATH;
     private Context mContext;
     private String BACKUP_PATH;
     private String BACKUP_DATABASES;
     private String BACKUP_SHARED_PREFS;

     public Backup(Context context) {
         mContext = context;
         ApkInfo apkInfo = new ResourceUtil(context).getApkInfo();
         APP_PATH = new StringBuilder("/data/data/").append(apkInfo.packageName)
                 .toString();
         SHARED_PREFS = APP_PATH + "/shared_prefs";
         DATABASES = APP_PATH + "/databases";
         if (Environment.MEDIA_MOUNTED.equals(Environment
                 .getExternalStorageState())) {
             BACKUP_PATH = "/sdcard/lurencun/backup";
         } else {
             BACKUP_PATH = "/com.lurencun/backup/";
             Toast.makeText(mContext, "没有检测到SD卡，可能无法备份成功", Toast.LENGTH_SHORT)
                     .show();
         }
         BACKUP_PATH += apkInfo.packageName;
         BACKUP_DATABASES = BACKUP_PATH + "/database";
         BACKUP_SHARED_PREFS = BACKUP_PATH + "/shared_prefs";
     }

     /**
      * 备份文件
      *
      * @return 当且仅当数据库及配置文件都备份成功时返回true。
      */
     public boolean doBackup() {
         return backupDB() && backupSharePrefs();
     }

     private boolean backupDB() {
         return copyDir(DATABASES, BACKUP_DATABASES, "备份数据库文件成功:"
                 + BACKUP_DATABASES, "备份数据库文件失败");
     }

     private boolean backupSharePrefs() {
         return copyDir(DATABASES, BACKUP_DATABASES, "备份配置文件成功:"
                 + BACKUP_SHARED_PREFS, "备份配置文件失败");
     }

     /**
      * 恢复
      *
      * @return 当且仅当数据库及配置文件都恢复成功时返回true。
      */
     public boolean doRestore() {
         return restoreDB() && restoreSharePrefs();
     }

     private boolean restoreDB() {
         return copyDir(BACKUP_DATABASES, DATABASES, "恢复数据库文件成功", "恢复数据库文件失败");
     }

     private boolean restoreSharePrefs() {
         return copyDir(BACKUP_SHARED_PREFS, SHARED_PREFS, "恢复配置文件成功",
                 "恢复配置文件失败");
     }

     private final void showToast(String msg) {
         Toast.makeText(mContext, msg, Toast.LENGTH_SHORT).show();
     }

     /**
      * 复制目录
      *
      * @param srcDir
      *            源目录
      * @param destDir
      *            目标目录
      * @param successMsg
      *            复制成功的提示语
      * @param failedMsg
      *            复制失败的提示语
      * @return 当复制成功时返回true, 否则返回false。
      */
     private final boolean copyDir(String srcDir, String destDir,
             String successMsg, String failedMsg) {
         try {
             FileUtils.copyDirectory(new File(srcDir), new File(destDir));
         } catch (IOException e) {
             e.printStackTrace();
             showToast(failedMsg);
             return false;
         }
         showToast(successMsg);
         return true;
     }
 }