java用户在发送消息时未收到推送通知。应用程序不会崩溃，所以不能说我哪里出错了。只是其他用户没有得到它们

Question

在我的应用程序中，当用户之间发送消息时，其他用户应收到推送通知。我看了一个教程来学习如何做到这一点，一年前的许多课程现在都被弃用了。无论如何，应用程序不会崩溃，但当用户发送消息时，不会显示任何通知

有人能告诉我我错过了什么吗？我可以看到Tokens节点是在Firebase中创建的，Tokens > UserId > Url，但正如我所说，其他用户没有收到推送通知

有人能指出我收到Toast信息的原因吗？每当有人发送消息时，唯一发生的事情就是我收到了Toast消息。没有别的事情发生。但是Toast消息为什么会响

MyFirebaseMessaging

public class MyFirebaseMessaging extends FirebaseMessagingService {

    String NOTIFICATION_CHANNEL_ID = "com.e.events";

    @Override
    public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);

        String sent = remoteMessage.getData().get("sent");

        FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();

        if (firebaseUser != null && sent.equals(firebaseUser.getUid())) {

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                sendOreoNotification(remoteMessage);
            } else {
                sendNotification(remoteMessage);
            }
        }
    }

    private void sendOreoNotification(RemoteMessage remoteMessage) {

        String user = remoteMessage.getData().get("user");
        String icon = remoteMessage.getData().get("icon");
        String title = remoteMessage.getData().get("title");
        String body = remoteMessage.getData().get("body");

        RemoteMessage.Notification notification = remoteMessage.getNotification();
        int j = Integer.parseInt(user.replaceAll("[\\D]", ""));
        Intent intent = new Intent(this, MessageActivity.class);
        Bundle bundle = new Bundle();
        bundle.putString("userid", user);
        intent.putExtras(bundle);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, j, intent, PendingIntent.FLAG_ONE_SHOT);
        Uri defaultSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);

        OreoNotification oreoNotification = new OreoNotification(this);
        Notification.Builder builder = oreoNotification.getOreoNotification(title, body, pendingIntent, defaultSound, icon);

        int i = 0;
        if (j > 0) {
            i = j;
        }

        oreoNotification.getManager().notify(i, builder.build());
    }

    private void sendNotification(RemoteMessage remoteMessage) {

        String user = remoteMessage.getData().get("user");
        String icon = remoteMessage.getData().get("icon");
        String title = remoteMessage.getData().get("title");
        String body = remoteMessage.getData().get("body");

        RemoteMessage.Notification notification = remoteMessage.getNotification();
        int j = Integer.parseInt(user.replaceAll("[\\D]", ""));
        Intent intent = new Intent(this, MessageActivity.class);
        Bundle bundle = new Bundle();
        bundle.putString("userid", user);
        intent.putExtras(bundle);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, j, intent, PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID)
                .setSmallIcon(Integer.parseInt(icon))
                .setContentTitle(title)
                .setContentText(body)
                .setAutoCancel(true)
                .setSound(defaultSound)
                .setContentIntent(pendingIntent);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        int i = 0;
        if (j > 0) {
            i = j;
        }

        notificationManager.notify(i, builder.build());
    }

    @Override
    public void onNewToken(@NonNull String s) {
        super.onNewToken(s);
        Log.d("TokenFirebase", s);

        FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();

        String refreshToken = FirebaseInstanceId.getInstance().getInstanceId().getResult().getToken();
        if (firebaseUser != null) {
            updateToken(refreshToken);
        }
    }

    private void updateToken(String refreshToken) {
        FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();

        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Tokens");
        Token token = new Token(refreshToken);
        reference.child(firebaseUser.getUid()).setValue(token);
    }
}

消息活动

private void sendNotification(String receiver, String username, String message) {
        DatabaseReference tokens = FirebaseDatabase.getInstance().getReference("Tokens");
        Query query = tokens.orderByKey().equalTo(receiver);
        query.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                    Token token = snapshot.getValue(Token.class);
                    Data data = new Data(mFirebaseUser.getUid(), R.mipmap.ic_launcher, username + ": " + message, "New Message", mId);

                    Sender sender = new Sender(data, token.getToken());

                    mAPIService.sendNotification(sender).enqueue(new Callback<MyResponse>() {
                        @Override
                        public void onResponse(Call<MyResponse> call, Response<MyResponse> response) {
                            if (response.code() == 200) {
                                if (response.body().success != 1) {
                                    Toast.makeText(MessageActivity.this, "Unsuccessful", Toast.LENGTH_SHORT).show();
                                }
                            }
                        }

                        @Override
                        public void onFailure(Call<MyResponse> call, Throwable t) {

                        }
                    });
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }