SimpleCloudNotifier/app/src/main/java/com/blackforestbytes/simplecloudnotifier/MainActivity.java

package com.blackforestbytes.simplecloudnotifier;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.InstanceIdResult;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                FirebaseInstanceId.getInstance().getInstanceId().addOnSuccessListener(new OnSuccessListener<InstanceIdResult>() {
                    @Override
                    public void onSuccess(InstanceIdResult instanceIdResult) {
                        Log.d("FB::ID", instanceIdResult.getId());
                        Log.d("FB::TOKEN", instanceIdResult.getToken());
                    }
                });
            }
        });
    }
}