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SharedPreferencesBackupHelper automatic recovery does not work

I am trying to use SharedPreferencesBackupHelper to store the value of SharedPreferences in the cloud.

AndroidManifest.xml

<application
    android:allowBackup="true"
    android:backupAgent=".DataBackupAgent"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >

    <meta-data android:name="com.google.android.backup.api_key" android:value="AEdPqrEAAAAIXMH86OqosQlXYuS0QbfyOaZT8fUadY1QUDzo2w" />

    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

DataBackupAgent.java:

Public class DataBackupAgent extends BackupAgentHelper {

public static final String PREFS = "data_prefs";
public static final String PREFS_BACKUP_KEY = "myprefs";

@Override
public void onCreate() {
    SharedPreferencesBackupHelper helper = new SharedPreferencesBackupHelper(this, PREFS);
    addHelper(PREFS_BACKUP_KEY, helper);
}

}

MainActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    backupManager = new BackupManager(this);
    prefs = getSharedPreferences(DataBackupAgent.PREFS, Context.MODE_PRIVATE);
    edit = prefs.edit();

    text = (EditText)findViewById(R.id.editText);
    String value = prefs.getString(DataBackupAgent.PREFS_BACKUP_KEY,"");
    text.setText(value);

    Button btnBackup = (Button)findViewById(R.id.button);
    btnBackup.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            edit.putString(DataBackupAgent.PREFS_BACKUP_KEY,text.getText().toString());
            edit.commit();
            backupManager.dataChanged();
        }
    });
}

My steps:

  • Write something in EditText, click the "Backup" button
  • Close the application and reopen. The saved value will be displayed in the EditText
  • Uninstall the application and reinstall it. The saved value is not displayed at all in EditText.

Edit on 02/27/2015:

I added the following manual recovery code:

    backupManager.requestRestore(new RestoreObserver() {
        @Override
        public void restoreFinished(int error) {
            super.restoreFinished(error);

            String value = prefs.getString(DataBackupAgent.PREFS_BACKUP_KEY,"");
            text.setText(value);
        }

        @Override
        public void restoreStarting(int numPackages) {
            super.restoreStarting(numPackages);
        }

        @Override
        public void onUpdate(int nowBeingRestored, String currentPackage) {
            super.onUpdate(nowBeingRestored, currentPackage);
        }
    });

Unfortunately, callback functions are not called.

This means that return or automatic recovery does not work at all. Any ideas? Thanks

+4
1

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