Question

Good Morning.

I have a question about how to create an application without GUI. It should start when the user pushes the icon. Reading other posts, seems that the natural way of doing this would be a Service.

Since the app has no GUI, it makes no sense to add any Activity. For this reason, the Service has to be unbinded. So, if there is no component calling startService, and no external component is sending an intent, ¿how does the service start?

Is there any attribute in the manifest to achieve this? Or maybe extending Application and using onCreate to start the service?

Thanks.

UPDATES:
-There’s no way to start a Service in the same app without an Intent. Other options would be autostart or Broadcast receivers, but these don’t fit my requirements.
-Tried a test app without Activities, and the icon isn’t even showing in the launcher. Don’t know the reason of this, maybe related to the manifest not having a LAUNCHER activity.

Answer 1

The list of applications shown in the Android launcher is basically the list of all activities in the system that have a LAUNCHER intent filter:

<intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

If you put this intent filter on a <service>, it will not work (just tried). Thus, the only way to do what you want to do is through an Activity. I think the cleanest way is something like this:

public void onCreate(Bundle savedInstanceState) {
    Intent service = new Intent(this, MyService.class);
    startService(service);
    Toast.makeText(this, "Service started.", Toast.LENGTH_SHORT).show();
    finish();
}

The user will not see anything except a small message at the bottom of the screen saying “Service started.” that will automatically disappear in a couple of seconds. It’s clean and user-friendly.