How do I programmatically “restart” an Android app?

Question

Firstly, I know that one should not really kill/restart an application on Android. In my use case, I want to factory-reset my application in a specific case where a server s

Answer 1

Intent i = getBaseContext().getPackageManager().getLaunchIntentForPackage( getBaseContext().getPackageName() );
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);

Answer 2

Try using FLAG_ACTIVITY_CLEAR_TASK

Answer 3

I had to add a Handler to delay the exit:

 mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 200, mPendingIntent);
        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                Runtime.getRuntime().exit(0);
            }
        }, 100);

Answer 4

You can simply call:

public static void triggerRebirth(Context context, Intent nextIntent) {
    Intent intent = new Intent(context, YourClass.class);
    intent.addFlags(FLAG_ACTIVITY_NEW_TASK);
    intent.putExtra(KEY_RESTART_INTENT, nextIntent);
    context.startActivity(intent);
    if (context instanceof Activity) {
      ((Activity) context).finish();
    }

    Runtime.getRuntime().exit(0);
}

Which is used in the ProcessPhoenix library

---

As an alternative:

Here's a bit improved version of @Oleg Koshkin answer.

If you really want to restart your activity including a kill of the current process, try following code. Place it in a HelperClass or where you need it.

public static void doRestart(Context c) {
        try {
            //check if the context is given
            if (c != null) {
                //fetch the packagemanager so we can get the default launch activity 
                // (you can replace this intent with any other activity if you want
                PackageManager pm = c.getPackageManager();
                //check if we got the PackageManager
                if (pm != null) {
                    //create the intent with the default start activity for your application
                    Intent mStartActivity = pm.getLaunchIntentForPackage(
                            c.getPackageName()
                    );
                    if (mStartActivity != null) {
                        mStartActivity.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                        //create a pending intent so the application is restarted after System.exit(0) was called. 
                        // We use an AlarmManager to call this intent in 100ms
                        int mPendingIntentId = 223344;
                        PendingIntent mPendingIntent = PendingIntent
                                .getActivity(c, mPendingIntentId, mStartActivity,
                                        PendingIntent.FLAG_CANCEL_CURRENT);
                        AlarmManager mgr = (AlarmManager) c.getSystemService(Context.ALARM_SERVICE);
                        mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 100, mPendingIntent);
                        //kill the application
                        System.exit(0);
                    } else {
                        Log.e(TAG, "Was not able to restart application, mStartActivity null");
                    }
                } else {
                    Log.e(TAG, "Was not able to restart application, PM null");
                }
            } else {
                Log.e(TAG, "Was not able to restart application, Context null");
            }
        } catch (Exception ex) {
            Log.e(TAG, "Was not able to restart application");
        }
    }

This will also reinitialize jni classes and all static instances.

Answer 5

Directly start the initial screen with FLAG_ACTIVITY_CLEAR_TASK and FLAG_ACTIVITY_NEW_TASK.

Answer 6

You can use startInstrumentation method of Activity. You need implement empty Instrumentation and pointed in manifest. After that you can call this method for restart your app. Like this:

try {           
    InstrumentationInfo info = getPackageManager().queryInstrumentation(getPackageName(), 0).get(0);
    ComponentName component = new ComponentName(this, Class.forName(info.name));
    startInstrumentation(component, null, null);
} catch (Throwable e) {             
    new RuntimeException("Failed restart with Instrumentation", e);
}

I get Instrumentation class name dynamically but you can hardcode it. Some like this:

try {           
    startInstrumentation(new ComponentName(this, RebootInstrumentation.class), null, null); 
} catch (Throwable e) {             
    new RuntimeException("Failed restart with Instrumentation", e);
}

Call startInstrumentation make reload of your app. Read description of this method. But it can be not safe if acting like kill app.