RegistrationIntentService.java

package com.example.barnes.ummo.gcm;

/**
 * Created by sihle on 12/3/15.
 */
import android.app.IntentService;
import android.content.Intent;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.util.Log;

import com.example.barnes.ummo.R;
import com.google.android.gms.gcm.GoogleCloudMessaging;
import com.google.android.gms.iid.InstanceID;

import java.io.IOException;

/**
 * Created by sihle on 11/28/15.
 */
public class RegistrationIntentService extends IntentService {
    private static final String TAG = "RegIntentService";

    public static final String SENT_TOKEN_TO_SERVER = "sentTokenToServer";
    public static final String GCM_TOKEN = "gcmToken";

    public RegistrationIntentService(){
        super(TAG);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        Log.d(TAG,"Handle Intenet");
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
        String token = "";
        InstanceID instanceID = InstanceID.getInstance(this);
        String senderId = getResources().getString(R.string.gcm_defaultSenderId);

        // Fetch token here
        try {

            token = instanceID.getToken(senderId, GoogleCloudMessaging.INSTANCE_ID_SCOPE);
            Log.d(TAG, "GCM Registration Token: " + token);


        } catch (IOException e) {
            Log.d(TAG, "Failed to complete token refresh", e);
            // If an exception happens while fetching the new token or updating our registration data
            // on a third-party server, this ensures that we'll attempt the update at a later time.
            sharedPreferences.edit().putBoolean(SENT_TOKEN_TO_SERVER, false).apply();
        }
        // save token
        sharedPreferences.edit().putString(GCM_TOKEN, token).apply();
        // pass along this data
        sendRegistrationToServer(token);
    }

    private void sendRegistrationToServer(String token) {
        // Add custom implementation, as needed.
    }
}