Is it possible to ignore plugged in Headset and still use phone speakers?

Question

I would like to use the Phone Speakers while a Headset is plugged-in, instead of the Headset-Speakers.

Is it possible to do that? if yes, how can I achieve it?
I'm developing an App in Java for Android 9.
Detection if Headset is Plugged in works so far:

public class HeadsetIntentReceiver extends BroadcastReceiver {
private String TAG = "HeadSet";

public HeadsetIntentReceiver() {
    Log.d(TAG, "Created");
}

@Override
public void onReceive(Context context, Intent intent) {
    if(intent.getAction().equals(Intent.ACTION_HEADSET_PLUG)) {
        int state = intent.getIntExtra("state", -1);
        switch(state) {
            case(0):
                Log.d(TAG, "Headset unplugged");
                break;
            case(1):
                Log.d(TAG, "Headset plugged");
                break;
            default:
                Log.d(TAG, "Error");
        }
    }
}
}

EDIT:
I tried the following Solutions, but Nothing happend:

1. How to mute audio in headset but let it play on speaker programmatically?

2. How to disable the wired headset programmatically in Java

   Thanks in Advance for any helpful advice.

---

(Please don't answer "Unplug the Headset")

Answer 1

I think you are looking for AudioManager

Attach AUDIO_SERVICE to AudioManager, set AudioManager as MODE_IN_COMMUNICATION and then set your speaker phone on. You can use the speaker as if you were talking on the phone.

AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
audioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
audioManager.setSpeakerphoneOn(true);

Remember to restore it after use. for example,

protected void onPause() {
    super.onPause();
    audioManager.setMode(AudioManager.MODE_NORMAL);
    audioManager.setSpeakerphoneOn(false);
}