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;
	}
}