Android数据库备份类

/**
 * Android数据库备份类
 */
public class BackupTask extends AsyncTask<String,Void,Integer> implements
        CompletionListener {
 
    // 定义常量
    public static final int BACKUP_SUCCESS = 1;
    public static final int RESTORE_SUCCESS = 2;
    public static final int BACKUP_ERROR = 3;
    public static final int RESTORE_NOFLEERROR = 4;
    public static final String COMMAND_BACKUP = "backupDatabase";
    public static final String COMMAND_RESTORE = "restroeDatabase";
    private Context mContext;
 
    public BackupTask(Context context) {
        this.mContext = context;
    }
 
    @Override
    protected Integer doInBackground(String... params) {
        // 1,获得数据库路径
        File dbFile = mContext.getDatabasePath("xxx.db");
        // 2,创建保存的数据库的路径
        File exportDir = new File(Environment.getExternalStorageDirectory(),"shopBackup");
        if (!exportDir.exists()) {
            exportDir.mkdirs();
        }
        File backup = new File(exportDir,dbFile.getName());
        // 3,检查操作
        String command = params[0];
        if (command.equals(COMMAND_BACKUP)) {
            // 复制文件
            try {
                backup.createNewFile();
                fileCopy(dbFile,backup);
                return BACKUP_SUCCESS;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return BACKUP_ERROR;
            }
        } else {
            return BACKUP_ERROR;
        }
 
    }
 
    private void fileCopy(File source,File dest) throws IOException {
        FileChannel inChannel = new FileInputStream(source).getChannel();
        FileChannel outChannel = new FileOutputStream(dest).getChannel();
        // FileInputStream fis = new FileInputStream(dbFile);
        // FileOutputStream fos = new FileOutputStream(backup);
        // byte buffer[] = new byte[4 * 1024];
        // while(fis.read(buffer) != -1){
        // fos.write(buffer);
        // }
        // fos.flush();
        //
        long size = inChannel.size();
        try {
            inChannel.transferTo(0,inChannel.size(),outChannel);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (inChannel != null) {
                inChannel.close();
            }
            if (outChannel != null) {
                outChannel.close();
            }
        }
    }
 
    @Override
    protected void onPostExecute(Integer result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        switch (result) {
        case BACKUP_SUCCESS:
            onBackupComplete();
            break;
 
        default:
            break;
        }
    }
 
    @Override
    public void onBackupComplete() {
 
        Log.d("backup","ok");
 
    }
 
    @Override
    public void onRestoreComplete() {
        // TODO Auto-generated method stub
 
    }
 
    @Override
    public void onError(int errorCode) {
        // TODO Auto-generated method stub
 
    }
 
}