exit app android exam

 private void quitApplication() {
  try {
   ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
   List<ActivityManager.RunningAppProcessInfo> process = manager
     .getRunningAppProcesses();
   int pid = 0;
   for (RunningAppProcessInfo runningAppProcessInfo : process) {
    if (runningAppProcessInfo.processName
      .equals(this.getPackageName())) {
     pid = runningAppProcessInfo.pid;
     break;
    }
   }
   android.os.Process.killProcess(pid);
  } catch (Exception e) {
   Log.e(TAG, TAG + e);
  }
 }