spring broker channel access

Question

I have a few questions one how to use spring websockets and messaging. So I have a program that interfaces with an external web service producer endpoint that will send data payloads to my web service consumer endpoint. While on the other end of my program I will be routing these data payloads to multiple websocket connections (stomp and sockjs). The external web service producer is providing a subscription ID in each data payload for every query requests so my approach is to send them back to the broker with a SimpMessagingTemplate with it's own unique destination (ie. /user/{subscriptionId}/subscribe). That way I can subscribe each websocket client to an existing destination if a duplicate query was made and only make requests for a new subscripion to the external web service producer if otherwise.

1. How do I access my SimpMessagingTemplate from within different component such as my web service consumer so that I can send the data payloads to my message broker? Do I just declare my SimpMessagingTemplate static and declare a getter function within my controller where the template object is stored?

2. How do I get a list of all known destinations and as well as the number of stomp client subscribers to each one? The external web service producer sets a termination time for each subscription, so I would like to implement auto renewal requests if there are still subscribers to a destination. I suppose I can keep track of it myself with Maps/Caches and update them everytime a websocket session is opened or closed, but i prefer to do it with spring if possible as it minimizes my risk and probably less error prone, or perhaps a full featured broker such as RabbitMQ or ActiveMQ is necessary to do this.

Answer 1

Found the answers I needed:

1. All I need to do is use spring Autowiring support and the bean will be injected with the object initialized

   @Autowired private SimpMessagingTemplate

2. Need a full featured broker for this, however for what I want to do i decided it would be too much work and essentially not needed. I decided I will just implement my own subscription checking with the 3rd party web service on my own with java maps/caches. I've set went to painstaking lengths by setting breakpoints in eclipse in the java .class files even with a java decompiler plugin and found out that all of this information can be found in the DefaultSubscriberRegistry class. Although I can not access it with the api given by Spring, I can rest assured it is being properly handled by the application. When a client subscribes or disconnects to my application, the information in the internal maps/caches of the registry are added and removed accordingly. Furthermore I can make make changes to my own implemented map/caches by implementing the interfaces provided by Spring such as SessionSubscribeEvent or SessionDisconnectedEvent and sub class it with ApplicationListener and they will be triggered whenever a client subscribes or disconnects.

   public class SubscribeEvent implements ApplicationListener