android數據庫備份還原

詳情參考  某android平板項目開發筆記—計劃任務備份/kf/201204/128614.html
新建一個類繼承 AsyncTask
 
public class BackupTask extends AsyncTask<String, Void, Integer> {
    private static final String COMMAND_BACKUP = "backupDatabase";
    public static final String COMMAND_RESTORE = "restroeDatabase";
    private static final int BACKUP_SUCCESS = 1;
    public static final int RESTORE_SUCCESS = 2;
    private static final int BACKUP_ERROR = 3;
    public static final int RESTORE_NOFLEERROR = 4;
    private Context mContext;

    public BackupTask(Context context) {
        this.mContext = context;
    }

    @Override
    protected Integer doInBackground(String… params) {
        // TODO Auto-generated method stub
        File dbFile = mContext.getDatabasePath("db_dlion.db");  // 獲得數據庫路徑,默認是/data/data/(包名)org.dlion/databases/
        File exportDir = new File(Environment.getExternalStorageDirectory(),
                "dbBackup");
        if (!exportDir.exists()) {
            exportDir.mkdirs();
        }
        File backup = new File(exportDir, dbFile.getName());
        String command = params[0];
        if (command.equals(COMMAND_BACKUP)) {
            try {
                backup.createNewFile();
                fileCopy(dbFile, backup);
                return BACKUP_SUCCESS;
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
                return BACKUP_ERROR;
            }
        } else if (command.equals(COMMAND_RESTORE)) {
            try {
                fileCopy(backup, dbFile);
                return RESTORE_SUCCESS;
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
                return RESTORE_NOFLEERROR;
            }
        } else {
            return BACKUP_ERROR;
        }
    }

    private void fileCopy(File dbFile, File backup) throws IOException {
        // TODO Auto-generated method stub
        FileChannel inChannel = new FileInputStream(dbFile).getChannel();
        FileChannel outChannel = new FileOutputStream(backup).getChannel();
        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();
            }
        }
    }

    protected void onPostExecute(Integer result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        switch (result) {
        case BACKUP_SUCCESS:
            Log.d("backup", "ok");
            break;

        case BACKUP_ERROR:
            Log.d("backup", "fail");
            break;
        case RESTORE_SUCCESS:
            Log.d("restore", "success");
            break;
        case RESTORE_NOFLEERROR:
            Log.d("restore", "fail");
            break;
        default:
            break;
        }
    }
}
 
在 mainActivity 裡異步加載備份、還原:
 
  // 數據恢復
    private void dataRecover() {
        // TODO Auto-generated method stub
        new BackupTask(this).execute("restroeDatabase");
    }

    // 數據備份
    private void dataBackup() {
        // TODO Auto-generated method stub
        new BackupTask(this).execute("backupDatabase");
    }

摘自 oldfeel

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