Firebase upstream messages

问题

When sending upstream message most of the times the message does not get to my server, and even when the message received to the server the onMessageSent(String msgId) function isn't called (the onMessageReceived(RemoteMessage fcmMessage) work very well).

Why the function isn't called and why do I need to send 10 upstream messages to get response from the firebase cloud messaging to my server?

new AsyncTask<Void, Void, String>() {
        @Override
        protected String doInBackground(Void... params) {
            String sendTo = SENDER_ID + "@gcm.googleapis.com";
            RemoteMessage.Builder data = new RemoteMessage.Builder(sendTo);
            data.addData("Hello", "World");

            try {
                for (int i = 0; i < 10; i++) {
                    Thread.sleep(1000);
                    String messageID = getRandomString();
                    data.setMessageId(messageID);
                    Logger.d(TAG, "messageID: " + messageID);
                    FirebaseMessaging.getInstance().send(data.build());

                }

            } catch (Exception e) {
                Logger.e(TAG, "Error sending upstream message: " + e.getMessage());
                return "Error sending upstream message:" + e.getMessage();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            if (result != null) {
                Logger.e(TAG, "send message failed: " + result);
            }
        }

    }.execute(null, null, null);

}

回答1:

Found out the problem!!! The problem was on the server side. Every time I send a message to the app (android), I started a new connection to the gcm server, when maintaining a continuous connection it worked great. For the problem with the onMessageSent not called it was because, before you send the message you need to set time to live (setTtl(Time_in_seconds)) for the message.

    RemoteMessage.Builder data = new RemoteMessage.Builder(mSendTo);

    data.setMessageId(messageID);
    data.setTtl(120);


    data.addData("Hello", "World");

    FirebaseMessaging.getInstance().send(data.build());

回答2:

buttonUpstreamEcho.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            Log.d(TAG, "Echo Upstream message logic");
            String message = editTextEcho.getText().toString();
            Log.d(TAG, "Message: " + message + ", recipient: " + token);
            FirebaseMessaging.getInstance().send(new RemoteMessage.Builder(FCM_PROJECT_SENDER_ID + FCM_SERVER_CONNECTION)
                    .setMessageId(Integer.toString(RANDOM.nextInt()))
                    .addData("message", message)
                    .addData("action", BACKEND_ACTION_ECHO)
                    .build());
            // To send a message to other device through the XMPP Server, you should add the
            // receiverId and change the action name to BACKEND_ACTION_MESSAGE in the data
        }
    });

This is a sample Android project to showcase the Firebase Cloud Messaging (FCM) to manage upstream and downstream messages.

https://github.com/carlosCharz/FCMTest

This is the video in youtube that explains what it does.

https://www.youtube.com/watch?v=SEzOKSoAMG0

Hope you find it useful.

回答3:

Using the builder pattern - it is always best to chain your calls to the setter methods. So my suggestion, and based on some working examples such as this one here, would be to change your code into something like this (note that I got rid of the for-loop - you can put it back if you need it, I don't see why - perhaps you were testing out?:

new AsyncTask<Void, Void, String>() {
        @Override
        protected String doInBackground(Void... params) {
            String sendTo = SENDER_ID + "@gcm.googleapis.com";
             String messageID = getRandomString();            
            try {
                FirebaseMessaging.getInstance().send(new RemoteMessage.Builder(sendTo)
                   .setMessageId(messageID)
                   .addData("my_message", "Hello, World")
                   .build());
            } catch (Exception e) {
                Logger.e(TAG, "Error sending upstream message: " + e.getMessage());
                return "Error sending upstream message:" + e.getMessage();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            if (result != null) {
                Logger.e(TAG, "send message failed: " + result);
            }
        }

    }.execute(null, null, null);

}

I hope this helps - try it out and let me know if it works or what errors you are getting.

来源：https://stackoverflow.com/questions/39724024/firebase-upstream-messages