This document summarizes the differences between Google Cloud Messaging (GCM) and Firebase Cloud Messaging (FCM). It outlines the changes needed for Android applications to migrate from GCM to FCM, including updating dependencies, removing permissions, changing receivers, listeners, and subscriber services. It also provides the new server endpoints for sending messages with FCM compared to GCM.

1. FCM &
GCM
Weihung
2016/06

2. About
 Name:Weihung Liu
 Android develop more than 5 years
 Innooz co, Ltd (英諾奧茲）
 FB:Android 開發者讀書會 板主
 FB:Weihung.TW

3. Agenda
 What is FCM
 Firebase Notification
 FCM & FN
 Dependencies
 Apply plugin
 Permissions
 Receiver
 Listener service
 InstanceIDListenerService
 Remove registration
 Subscribe to topic
 Server endpoints
 Firebase notification

4. What is FCM
Google Cloud Message say:
Firebase Cloud Message(FCM) is
the new version of GCM.

5. Firebase Notifications
 Firebase Notifications is a lightweight,
serverless messaging solution built on
Firebase Cloud Messaging.
 With a user-friendly graphical console and
reduced coding requirements.
 Lets users easily send messages to reengage
and retain users.

6. FCM & FN
https://firebase.google.com/support/faq/#messaging-difference

7. Android Dependencies
 Before
compile "com.google.android.gms:play-services-
gcm:8.4.0”
 After
compile "com.google.firebase:firebase-
messaging:9.0.2”

8. Apply plugin
 Add in the end of build.gradle
apply plugin: 'com.google.gms.google-services'

9. Android Permissions
 Before
<uses-permission
android:name="android.permission.WAKE_LOCK" />
<permission android:name="<your-package-
name>.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="<your-package-
name>.permission.C2D_MESSAGE" />
 After
No permissions

10. Android Receiver
 Before
<receiver
android:name="com.google.android.gms.gcm.GcmReceiver"
android:exported="true"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="com.example.gcm" />
</intent-filter>
</receiver>
 After
No receiver

11. Android Listener service
 A service extending InstanceIDListenerService
is now required only if you want to access the
FCM token.
 Manage device tokens to send a messages to
single device directly
 Send messages to device group
 Subscribe devices to topics with the server

12. Android
InstanceIDListenerService
 Before
public class MyInstanceIDListenerService extends
InstanceIDListenerService {
...
@Override
public void onTokenRefresh() {
Intent intent = new Intent(this,
RegistrationIntentService.class);
startService(intent);
}
}

13. Android
InstanceIDListenerService
 After
public class MyInstanceIDListenerService extends
FirebaseInstanceIdService {
...
@Override
public void onTokenRefresh() {
String refreshedToken =
FirebaseInstanceId.getInstance().getToken();
sendRegistrationToServer(refreshedToken);
}
}

14. Android Remove registration
 You no longer need to explicitly initiate the
generation of a registration token — the library
does this automatically
Before
InstanceID instanceID = InstanceID.getInstance(this);
String token =
instanceID.getToken(getString(R.string.gcm_defaultSenderId),
GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);
After
String token = FirebaseInstanceId.getInstance().getToken();

15. Android Listener service
 Before
<service
android:name=".MyInstanceIDListenerService"
android:exported="false">
<intent-filter>
<action android:name="com.google.android.gms.iid.InstanceID" />
</intent-filter>
</service>
 After
<service
android:name=".MyInstanceIDListenerService">
<intent-filter>
<action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
</intent-filter>
</service>

16. Android Listener service
 Before
public class MyGcmListenerService extends
GcmListenerService {
@Override
public void onMessageReceived(String from,
Bundle data){
...
}
}

17. Android Listener service
 After
public class MyFcmListenerService extends
FirebaseMessagingService {
@Override
public void onMessageReceived(RemoteMessage
message){
String from = message.getFrom();
Map data = message.getData();
}
...
}

18. Android Subscribe to topic
 Before
// Blocking methods. Execute them inside an AsyncTask or
background thread.
GcmPubSub.getInstance(context).subscribe("token",
"/topics/mytopic", null /* extras bundle */);
GcmPubSub.getInstance(context).unsubscribe("token",
"/topics/mytopic");
 After
// Non-blocking methods. No need to use AsyncTask or
background thread.
FirebaseMessaging.getInstance().subscribeToTopic("mytopic"
);
FirebaseMessaging.getInstance().unsubscribeToTopic("mytop
ic");

19. Server endpoints
 Before
 gcm-http.googleapis.com/gcm/
 gcm-xmpp.googleapis.com
 After
 fcm.googleapis.com/fcm/
 fcm-xmpp.googleapis.com

20. Firebase notification

21. Firebase notification

22. Firebase notification

23. Firebase notification

24. Firebase notification

25. Q&A