SharedPreferences getSharedPreferences always returns previous value even it has been changed

Question

I have a service that is started when the main activity starts. I call the Service using this code

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    startService(new Intent(this, CheckService.class));
    finish();
}

The Service has the following code:

public class CheckService extends Service {

private static final String TAG = "CheckService";
WakeLock wakeLock;



public CheckService() {
    // TODO Auto-generated constructor stub
}

@Override
public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    // TODO Auto-generated method stub
    return START_STICKY;
}

@Override
public void onTaskRemoved(Intent rootIntent) {
    // TODO Auto-generated method stub
    Intent restartService = new Intent(getApplicationContext(),
            this.getClass());
    restartService.setPackage(getPackageName());
    PendingIntent restartServicePI = PendingIntent.getService(
            getApplicationContext(), 1, restartService,
            PendingIntent.FLAG_ONE_SHOT);

    //Restart the service once it has been killed android


    AlarmManager alarmService = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
    alarmService.set(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime() + 100, restartServicePI);

}

@Override
public void onCreate() {
    // TODO Auto-generated method stub
    super.onCreate();

    PowerManager pm = (PowerManager) getSystemService(this.POWER_SERVICE);

    wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "DoNotSleep");

    Log.e("Checker", "Service Created");

    Timer myTimer = new Timer();
    myTimer.schedule(new TimerTask() {
        @Override
        public void run() {
            check_pref();

        }
    }, 0, 5000);


}

@Override
@Deprecated
public void onStart(Intent intent, int startId) {
    // TODO Auto-generated method stub
    super.onStart(intent, startId);



}


@Override
public void onDestroy() {
    super.onDestroy();
    sendBroadcast(new Intent("YouWillNeverKillMe"));
}



public void check_pref( ) {
    Context con;
    Log.e("check_pref", "Restarting");

    try {

        Process   p = Runtime.getRuntime().exec("su");
        DataOutputStream dos = new DataOutputStream(p.getOutputStream());
        dos.writeBytes("chmod -R 0777 /data/data/com.my.project.app/\n");
        dos.writeBytes("exit\n");
        dos.flush();
        dos.close();
        p.waitFor();
        p.destroy();
        con = createPackageContext("com.my.project.app", 0);
        SharedPreferences pref = con.getSharedPreferences("myprefs", 0);
        String login_id = pref.getString("login", "");
        System.out.println(login_id);

    }   catch (PackageManager.NameNotFoundException e)

    {
        Log.e("check_pref", e.toString());
    }


    catch (NullPointerException e){
        e.printStackTrace();
    }
    catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
    catch (InterruptedException e){
    e.printStackTrace();
}

}
}

Every 5 seconds in my service runs method check_pref(), which checks login in another app (com.my.project.app) and prints it in Logcat. But even login has been changed it returns same value as previously. Only if I restart app it returns actual value. My device(android 5.1.1) is rooted and I allowed permissions for my app. Whats wrong with my code? How to make it always return the actual value, which located in /data/data/com.my.project.app/myprefs.xml ?

PS. I found a solution. I changed SharedPreferences pref = con.getSharedPreferences("myprefs", 0); to SharedPreferences pref = con.getSharedPreferences("myprefs", MODE_MULTI_PROCESS); and it works now.

Where are the SharedPreferences saved? Are you sure that the value is correctly stored? — Al0x, Nov 25 '17 at 08:53
[This](https://stackoverflow.com/questions/10186215/sharedpreferences-value-is-not-updated) may help you. also see [this](https://stackoverflow.com/a/14129373/5894421) — J4GD33P 51NGH, Nov 25 '17 at 08:53
SharedPreferences saved by third party app (com.my.project.app) and located in /data/data/com.my.project.app/myprefs.xml. Yes I checked by opening myprefs.xml in file manager. Like I said, first time when I starting my app its displays value as in myprefs.xml. — TheEldrone, Nov 25 '17 at 08:59

score 1 · Accepted Answer · edited Jan 08 '18 at 22:14

1

I changed

SharedPreferences pref = con.getSharedPreferences("myprefs", 0);

to

SharedPreferences pref = con.getSharedPreferences("myprefs", MODE_MULTI_PROCESS);

and it works now.

edited Jan 08 '18 at 22:14

Paul Roub

36,322
27
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answered Jan 08 '18 at 21:46

TheEldrone

87
1
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SharedPreferences getSharedPreferences always returns previous value even it has been changed

1 Answers1