FCM 푸시 알림

manifest 에 서비스 등록

<service android:name=”.MyFireBaseMessagingService”>
<intent-filter>
<action android:name=”com.google.firebase.MESSAGING_EVENT” />
</intent-filter>
</service>

인터넷 권한 허용

<uses–permission android:name=“android.permission.INTERNET”></uses–permission>

MyFireBaseMessagingService.java

public class MyFireBaseMessagingService extends FirebaseMessagingService {
    @Override
    public void onNewToken(String token) {
        Log.d("FCM Log", "Refreshed token: " + token);
    }
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        if (remoteMessage.getNotification() != null) {
            Log.d("FCM Log", "알림 메시지: " + remoteMessage.getNotification().getBody());
            String messageBody = remoteMessage.getNotification().getBody();
            String messageTitle = remoteMessage.getNotification().getTitle();
            Intent intent = new Intent(this, MainActivity.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_ONE_SHOT);
            String channelId = "Channel ID";
            Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
            NotificationCompat.Builder notificationBuilder =
                    new NotificationCompat.Builder(this, channelId)
                            .setSmallIcon(R.mipmap.ic_launcher)
                            .setContentTitle(messageTitle)
                            .setContentText(messageBody)
                            .setAutoCancel(true)
                            .setSound(defaultSoundUri)
                            .setContentIntent(pendingIntent);
            NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                String channelName = "Channel Name";
                NotificationChannel channel = new NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH);
                notificationManager.createNotificationChannel(channel);
            }
            notificationManager.notify(0, notificationBuilder.build());
        }
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FirebaseInstanceId.getInstance().getInstanceId()
                .addOnCompleteListener(new OnCompleteListener() {
                    @Override
                    public void onComplete(@NonNull Task task) {
                        if (!task.isSuccessful()) {
                            Log.w("FCM Log", "getInstanceId failed", task.getException());
                            return;
                        }
                        String token = task.getResult().getToken();
                        Log.d("FCM Log", "FCM 토큰: " + token);
                        Toast.makeText(MainActivity.this, token, Toast.LENGTH_SHORT).show();
                    }
                });
    }
}

Firebase
https://console.firebase.google.com/

안드로이드 앱 FCM 푸시 알림 예제 (+ 서버에서 푸시 알림 보내기)
http://blog.naver.com/PostView.nhn?blogId=ndb796&logNo=221553341369

안드로이드 FCM 푸시 알림 구현
https://triest.tistory.com/40

안드로이드 앱 만들기 #19 (FCM 푸시알림) – 홍드로이드
https://www.youtube.com/watch?v=pPMEgVarhWU

홍드로이드 github
https://github.com/hongdroid94/19_FCM