我正在处理一个必须接收推送通知的应用程序，我尽一切努力使它工作，但它不工作，这是我的代码

public class MyFirebaseInstanceService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
        if (remoteMessage.getData().isEmpty()) {

            showNotification(remoteMessage.getNotification().getTitle(), remoteMessage.getNotification().getBody());
        }

        else
        {
            showNotification(remoteMessage.getData());

        }

    }

    private void showNotification(Map<String, String> data) {
        String title = data.get("title").toString();
        String body = data.get("body").toString();

        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "example.myapplication.service.test";

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
        {
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,"Notification",
                    NotificationManager.IMPORTANCE_DEFAULT);

            notificationChannel.setDescription("Team Tarang");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.BLUE);
            notificationChannel.enableLights(true);
            notificationManager.createNotificationChannel(notificationChannel);
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this,NOTIFICATION_CHANNEL_ID);

        notificationBuilder.setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_ALL)
                .setWhen(System.currentTimeMillis())
                .setContentTitle(title)
                .setContentText(body)
                .setContentInfo("Info");

        notificationManager.notify(new Random().nextInt(),notificationBuilder.build());

    }

    private void showNotification(String title, String body) {
        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "example.myapplication.service.test";

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
        {
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,"Notification",
                    NotificationManager.IMPORTANCE_DEFAULT);

            notificationChannel.setDescription("Team Tarang");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.BLUE);
            notificationChannel.enableLights(true);
            notificationManager.createNotificationChannel(notificationChannel);
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this,NOTIFICATION_CHANNEL_ID);

        notificationBuilder.setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_ALL)
                .setWhen(System.currentTimeMillis())
                .setContentTitle(title)
                .setContentText(body)
                .setContentInfo("Info");

        notificationManager.notify(new Random().nextInt(),notificationBuilder.build());
    }

    @Override
    public void onNewToken(String s) {
        super.onNewToken(s);

        Log.d("TOKENFIREBASE",s);
    }
}

这是我的androidmanifest.xml代码

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.almohamady.pushnotifications">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service
            android:name=".services.MyFirebaseMessagingService"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
            </intent-filter>
        </service>

    </application>

</manifest>

我已经通过firebaseandroid studio工具建立了连接，比如这张照片

任何人都可以帮我解决这个问题。