数据库备份和恢复代码,Java代码库,德仔网

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【Java】数据库备份和恢复
作者:523450269 / 发布于2013/7/19/ 803

	package cn.fly.backup;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.nio.channels.FileChannel;
	import java.text.SimpleDateFormat;
	import java.util.Date;

	import android.app.AlertDialog;
	import android.content.Context;
	import android.content.DialogInterface;
	import android.content.DialogInterface.OnClickListener;
	import android.os.AsyncTask;
	import android.os.Environment;
	import android.view.ViewGroup.LayoutParams;
	import android.view.Window;
	import android.view.WindowManager;
	import android.widget.ProgressBar;
	import android.widget.Toast;

	public class BackupAndRestore {
	private Context mContext = null;
	private String[] fileList = null; // 数据库文件列表
	private int choicePostion = -3; // 选择数据库列表中的位置
	private AlertDialog dialog = null;
	private String BACK_FOLDER = "backup";
	private String appName = "myApp";

	public BackupAndRestore(Context context) {
	 mContext = context;
	}

	/**
	 * 恢复数据的Dialog
	 */
	public void restoreDB() {
	 fileList = getFileList();
	 AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
	 builder.setIcon(android.R.drawable.ic_dialog_info);
	 builder.setTitle("恢复");
	 builder.setSingleChoiceItems(getFileList(), -1, new DialogClick());
	 builder.setPositiveButton("确定", new DialogClick());
	 builder.setNegativeButton("取消", new DialogClick());
	 builder.show();
	}

	/**
	 * 备份数据库
	 */
	public void backupDB() {
	 showDialog("是否备份数据库", 'B');
	}

	/**
	 * 显示一个Dialog
	 *
	 * @param title
	 * 标题 ，必须引用资源ID resource ID
	 * @param sign
	 * 根据标示调用方法 I - 恢复默认设置 D - 恢复默认设置 H -选择主机
	 */
	private void showDialog(String title, char sign) {
	 final char s = sign;
	 new AlertDialog.Builder(mContext).setTitle(title)
	 .setPositiveButton("确定", new OnClickListener() {
	 @Override
	 public void onClick(DialogInterface dialogI, int which) {
	 switch (s) {
	 case 'B': // 备份数据库
	 if (dialog == null) {
	 dialog = awaitDialog(mContext);
	 } else {
	 dialog.show();
	 }
	 new ExecuteTask().execute('B');
	 break;
	 default:
	 break;
	 }
	 }
	 }).setNegativeButton("取消", new OnClickListener() {
	 @Override
	 public void onClick(DialogInterface dialog, int which) {
	 }
	 }).show();
	}

	/**
	 * 备份操作
	 *
	 * @return
	 */
	private boolean backUp() {
	 boolean isOk = false;
	 String sp = File.separator;
	 File sdFile = sdCardOk();
	 if (sdFile != null) {
	 try {
	 String[] dbNames = { "数据库名称" };
	 // 创建日期文件夹
	 String folder_date = datePrefix();
	 File f = new File(sdFile.getAbsolutePath() + sp + folder_date);
	 if (!f.exists()) {
	 f.mkdirs();
	 }
	 for (int i = 0; i < dbNames.length; i++) {
	 String dbName = dbNames[i];
	 File dbFile = dbOk(dbName);
	 if (dbFile != null) {
	 File backFile = new File(f.getAbsolutePath() + sp
	 + dbFile.getName());
	 backFile.createNewFile();
	 isOk = fileCopy(backFile, dbFile.getAbsoluteFile());
	 if (!isOk) {
	 break;
	 }
	 }
	 }
	 } catch (IOException e) {
	 // TODO Auto-generated catch block
	 e.printStackTrace();
	 }
	 }
	 return isOk;
	}

	/**
	 * 时间前缀
	 *
	 * @return
	 */
	private String datePrefix() {
	 SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
	 Date date = new Date(System.currentTimeMillis());
	 String str = format.format(date);
	 return str;
	}

	/**
	 * 文件夹列表
	 *
	 * @return
	 */
	private String[] getFileList() {
	 String[] fileList = null;
	 File file = sdCardOk();
	 if (file != null) {
	 File[] list = file.listFiles();
	 if (list != null && list.length > 0) {
	 fileList = new String[list.length];
	 for (int i = 0; i < list.length; i++) {
	 fileList[i] = list[i].getName();
	 }
	 }
	 }
	 return fileList;
	}

	/**
	 * sdCard是否存在 备份的文件夹是否存在
	 *
	 * @return null不能使用
	 */
	private File sdCardOk() {
	 File bkFile = null;
	 String state = Environment.getExternalStorageState();
	 if (Environment.MEDIA_MOUNTED.equals(state)) {
	 String sp = File.separator;
	 String backUpPath = Environment.getExternalStorageDirectory() + sp
	 + appName + sp + BACK_FOLDER;
	 bkFile = new File(backUpPath);
	 if (!bkFile.exists()) {
	 bkFile.mkdirs();
	 } else
	 return bkFile;
	 } else
	 Toast.makeText(mContext, "Sdcard 不存在", Toast.LENGTH_SHORT).show();
	 return bkFile;
	}

	/**
	 * 恢复数据库
	 *
	 * @param name
	 * 选择的文件名称 选中的数据库名称
	 * @param resoreDbName
	 * 需要恢复的数据库名称
	 * @return
	 */
	public boolean restore(String name, File f) {
	 boolean isOk = false;
	 if (f != null) {
	 File dbFile = dbOk(name);
	 try {
	 // System.out.println("覆盖的名称"+dbName);
	 if (dbFile != null) {
	 isOk = fileCopy(dbFile, f.getAbsoluteFile());
	 } else
	 isOk = false;
	 } catch (IOException e) {
	 e.printStackTrace();
	 }
	 }
	 return isOk;
	}

	/**
	 * 数据库文件是否存在，并可以使用
	 *
	 * @return
	 */
	private File dbOk(String dbName) {
	 String sp = File.separator;
	 String absPath = Environment.getDataDirectory().getAbsolutePath();
	 String pakName = mContext.getPackageName();
	 String dbPath = absPath + sp + "data" + sp + pakName + sp + "databases"
	 + sp + dbName;
	 File file = new File(dbPath);
	 if (file.exists()) {
	 return file;
	 } else {
	 return null;
	 }
	}

	/**
	 * 等候动画
	 */
	public AlertDialog awaitDialog(Context context) {
	 ProgressBar bar = new ProgressBar(context);
	 bar.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
	 LayoutParams.WRAP_CONTENT));
	 AlertDialog dialog = new AlertDialog.Builder(context).create();
	 dialog.setCancelable(false);
	 dialog.show();
	 Window window = dialog.getWindow();
	 WindowManager.LayoutParams params = window.getAttributes();
	 params.width = 50;
	 params.height = 50;
	 window.setAttributes(params);
	 window.setContentView(bar);
	 return dialog;
	}

	/**
	 *
	 * @param outFile
	 * 写入
	 * @param inFile
	 * 读取
	 * @throws FileNotFoundException
	 */
	private boolean fileCopy(File outFile, File inFile) throws IOException {
	 if (outFile == null || inFile == null) {
	 return false;
	 }
	 boolean isOk = true;
	 FileChannel inChannel = new FileInputStream(inFile).getChannel();// 只读
	 FileChannel outChannel = new FileOutputStream(outFile).getChannel();// 只写
	 try {
	 long size = inChannel.transferTo(0, inChannel.size(), outChannel);
	 if (size <= 0) {
	 isOk = false;
	 }
	 } catch (IOException e) {
	 isOk = false;
	 e.printStackTrace();
	 } finally {
	 if (inChannel != null) {
	 inChannel.close();
	 }
	 if (outChannel != null) {
	 outChannel.close();
	 }
	 }
	 return isOk;
	}

	private class DialogClick implements DialogInterface.OnClickListener {
	 @Override
	 public void onClick(DialogInterface dialog, int which) {
	 if (which == -1) {// 确定
	 if (choicePostion < 0) {
	 Toast.makeText(mContext, "选择数据库", Toast.LENGTH_SHORT)
	 .show();
	 return;
	 }
	 String sp = File.separator;
	 String folderName = fileList[choicePostion];
	 String backUpPath = Environment.getExternalStorageDirectory()
	 + sp + appName + sp + BACK_FOLDER + sp + folderName;
	 File file = new File(backUpPath);
	 if (file.isDirectory()) {
	 File[] files = file.listFiles();
	 boolean isOk = false;
	 for (int i = 0; i < files.length; i++) {
	 File f = files[i];
	 isOk = restore(f.getName(), f);
	 if (!isOk) {
	 String fail_msg = "恢复失败" + ":" + f.getName();
	 Toast.makeText(mContext, fail_msg,
	 Toast.LENGTH_SHORT).show();
	 return;
	 }
	 }
	 if (isOk) {
	 // 如果有数据体现则需要刷新出新的数据

	 }
	 }
	 } else if (which == -2) {// 取消
	 } else if (which >= 0) {
	 choicePostion = which;
	 }
	 }
	}

	/**
	 * 执行任务
	 *
	 * @author Administrator
	 *
	 */
	private class ExecuteTask extends AsyncTask<Character, Void, Boolean> {
	 @Override
	 protected Boolean doInBackground(Character... params) {
	 char c = params[0];
	 if (c == 'B') {
	 backUp();
	 }
	 return null;
	 }

	 @Override
	 protected void onPostExecute(Boolean result) {
	 super.onPostExecute(result);
	 if (dialog != null) {
	 dialog.dismiss();
	 }
	 }
	}
	}
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