Android - Show Toast from Service

android-serviceToast.java

// If you Service with threads, e.g. a Chat Service
// You want to show a toast such as indicating the connection is lost or stuff when your service is running foreground
// Get main the main thread, you are only allowed to draw UI in the main thread

Handler mainHandler = new Handler(getMainLooper());

 mainHandler.post(new Runnable() {
            @Override
            public void run() {
                // Do your stuff here related to UI, e.g. show toast
                Toast.makeText(getApplicationContext(), "I'm a toast!", Toast.LENGTH_SHORT).show();
            }
        });

// You can use this code if you use OkHTTP