FCM clients require devices running Android 4.4 or higher that also have the Google Play Store app installed, or an emulator running Android 4.4 with Google APIs. Note that you are not limited to deploying your Android apps through Google Play Store.
Set up the SDK
This section covers tasks you may have completed if you have already enabled other Firebase features for your app. If you haven't already, add Firebase to your Android project
Edit your app manifest
Add the following to your app's manifest:
- A service that extends
FirebaseMessagingService. This is required if you want to do any message handling beyond receiving notifications on apps in the background. To receive notifications in foregrounded apps, to receive data payload, to send upstream messages, and so on, you must extend this service.
<service
android:name=".java.MyFirebaseMessagingService"
android:exported="false">
<intent-filter>
<action android:name="com.google.firebase.MESSAGING_EVENT" />
</intent-filter>
</service>
<!-- Set custom default icon. This is used when no icon is set for incoming notification messages.
See README(https://goo.gl/l4GJaQ) for more. -->
<meta-data
android:name="com.google.firebase.messaging.default_notification_icon"
android:resource="@drawable/ic_stat_ic_notification" />
<!-- Set color used with incoming notification messages. This is used when no color is set for the incoming
notification message. See README(https://goo.gl/6BKBk7) for more. -->
<meta-data
android:name="com.google.firebase.messaging.default_notification_color"
android:resource="@color/colorAccent" />
default_notification_channel_id to the ID of your notification channel object
as shown; FCM will use this
value whenever incoming messages do not explicitly set a notification
channel. To learn more, see
Manage notification channels.
<meta-data
android:name="com.google.firebase.messaging.default_notification_channel_id"
android:value="@string/default_notification_channel_id" />
Access the device registration token
On initial startup of your app, the FCM SDK generates a registration
token for the client app instance. If you want to target single devices or
create device groups, you'll need to access this token by extending
FirebaseMessagingService and overriding onNewToken.
This section describes how to retrieve the token and how to monitor changes to the token. Because the token could be rotated after initial startup, you are strongly recommended to retrieve the latest updated registration token.
The registration token may change when:
- The app is restored on a new device
- The user uninstalls/reinstall the app
- The user clears app data.
Retrieve the current registration token
When you need to retrieve the current token, call
FirebaseMessaging.getInstance().getToken():
Java
FirebaseMessaging.getInstance().getToken()
.addOnCompleteListener(new OnCompleteListener<String>() {
@Override
public void onComplete(@NonNull Task<String> task) {
if (!task.isSuccessful()) {
Log.w(TAG, "Fetching FCM registration token failed", task.getException());
return;
}
// Get new FCM registration token
String token = task.getResult();
// Log and toast
String msg = getString(R.string.msg_token_fmt, token);
Log.d(TAG, msg);
Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
}
});
Kotlin+KTX
FirebaseMessaging.getInstance().token.addOnCompleteListener(OnCompleteListener { task ->
if (!task.isSuccessful) {
Log.w(TAG, "Fetching FCM registration token failed", task.exception)
return@OnCompleteListener
}
// Get new FCM registration token
val token = task.result
// Log and toast
val msg = getString(R.string.msg_token_fmt, token)
Log.d(TAG, msg)
Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
})
Monitor token generation
The onNewToken callback fires whenever a new token is generated.
Java
/**
* There are two scenarios when onNewToken is called:
* 1) When a new token is generated on initial app startup
* 2) Whenever an existing token is changed
* Under #2, there are three scenarios when the existing token is changed:
* A) App is restored to a new device
* B) User uninstalls/reinstalls the app
* C) User clears app data
*/
@Override
public void onNewToken(String token) {
Log.d(TAG, "Refreshed token: " + token);
// If you want to send messages to this application instance or
// manage this apps subscriptions on the server side, send the
// FCM registration token to your app server.
sendRegistrationToServer(token);
}
Kotlin+KTX
/**
* Called if the FCM registration token is updated. This may occur if the security of
* the previous token had been compromised. Note that this is called when the
* FCM registration token is initially generated so this is where you would retrieve the token.
*/
override fun onNewToken(token: String) {
Log.d(TAG, "Refreshed token: $token")
// If you want to send messages to this application instance or
// manage this apps subscriptions on the server side, send the
// FCM registration token to your app server.
sendRegistrationToServer(token)
}
After you've obtained the token, you can send it to your app server and store it using your preferred method.
Check for Google Play services
Apps that rely on the Play Services SDK
should always check the device for a compatible Google Play services APK before
accessing Google Play services features. It is recommended to do this in
two places: in the main activity's onCreate() method, and in its
onResume() method. The check in onCreate() ensures that the app
can't be used without a successful check. The check in onResume() ensures
that if the user returns to the running app through some other means, such as
through the back button, the check is still performed.
If the device doesn't have a compatible version of Google Play services, your app can call
GoogleApiAvailability.makeGooglePlayServicesAvailable()
to allow users to download Google Play services from the Play Store.
Prevent auto initialization
When an FCM registration token is generated, the library uploads
the identifier and configuration data to
Firebase. If you prefer to prevent token autogeneration, disable Analytics collection and
FCM auto initialization (you must disable both) by adding these metadata values to your
AndroidManifest.xml:
<meta-data
android:name="firebase_messaging_auto_init_enabled"
android:value="false" />
<meta-data
android:name="firebase_analytics_collection_enabled"
android:value="false" />
To re-enable FCM auto-init, make a runtime call:
Java
FirebaseMessaging.getInstance().setAutoInitEnabled(true);
Kotlin+KTX
Firebase.messaging.isAutoInitEnabled = true
To re-enable Analytics collection, call the
setAnalyticsCollectionEnabled()
method of the FirebaseAnalytics class. For example:
setAnalyticsCollectionEnabled(true);
These values persist across app restarts once set.
Next steps
After the client app is set up, you are ready to start sending downstream messages with the Notifications composer. This functionality is demonstrated in the quickstart sample, which you can download, run, and review.
To add other, more advanced behavior to your app, you can declare an intent filter and implement an activity to respond to incoming messages. For details, see the guides for sending messages from an app server:
Keep in mind that, to take advantage of these features, you'll need a server implementation and the server procotols (HTTP or XMPP), or an implementation of the Admin SDK.