I would like an example/sample code of 2 simple spring web/java applications where I need to send messages from the 1 and the 2nd application must receive the messages and respond back. I looked at few that had request/response in the same application but unable to separate them. I'm new to Amqp & RabbitMQ. Any help or direction would be greatly appreciated.
Thanks
See the stock trading sample, request reply messaging (client side) and MessageListenerAdapter which automatically handles request/reply on the server side (where your service is a POJO).
Related
I have recently developed a simple messaging application with Spring Boot and Spring Security. The application takes in 2 users - user A and user B. Once, user A performs a specific task a notification is sent to user B. Currently I am doing this by adding a Spring Messaging dependency and SockJS and it works great.
Here is where I am confused and hoping to receive some guidance. I realize there are many tutorials that speak about RabbitMQ and ActiveMQ. From what I understand, they are message brokers. May I ask what is the difference between SockJS and RabbitMQ/ActiveMQ? And do I need RabbitMQ/ActiveMQ in my current application together with SockJS?
SockJS is JavaScript based WebSocket client library that runs in a browser. It can be used to send messages to or receive messages from a broker.
Both RabbitMQ and ActiveMQ are message brokers, examples of message-oriented middleware. They both support WebSocket clients which use a messaging protocol (e.g. STOMP or AMQP). Brokers receive messages from and dispatch messages to clients.
You haven't really provided enough information to determine whether or not you actually need to use either RabbitMQ or ActiveMQ in your current application given that it's already working as it is.
After make a search about different ways to implement it, im stuck.
What im looking for is to realize this example (https://www.rabbitmq.com/tutorials/tutorial-six-spring-amqp.html) with Spring Integration.
I had found interesting post as this (Spring integration with Rabbit AMQP for "Client Sends Message -> Server Receives & returns msg on return queue --> Client get correlated msg") but didn't help me with what i need.
My case mill be a system where a client call the "convertSendAndReceive" method and a server (basede on Spring Integration) will response.
Thanks
According to your explanation it sounds like Outbound Gateway on the Client side and Inbound Gateway on the Server side pair is what you need.
Spring Integration AMQP support provides those implementations for you with built-in correlation functionality: https://docs.spring.io/spring-integration/docs/5.0.0.RELEASE/reference/html/amqp.html
Can I send a message to a message broker using SimpMessagingTemplate#convertAndSendToUser or SimpMessagingTemplate#convertAndSend methods without settings up a websocket message broker using #EnableWebSocketMessageBroker?
What I'm trying to do is utilise one websocket server to provide messaging for two application server instances(One spring 4 and one Spring 3). I created a one web server with Spring 4, Spring boot plus websocket message broker enabled.
Now I want two application servers to push messages to rabbitmq so it will broadcast them to clients subscribed to it.
First issue I faced is if there is no websockt message broker configuration available, SimpMessagingTemplate will not get autowired to application context. I couldn't get it injected without creating a websocket message board either.
Please help me to find out whether this is possible.
BTW I have a previous question unanswered related to this.
Well, After reading lots of documentation I found the answer myself. The key thing is this architecture is following.
In this architecture spring act as a gateway for communication between the message broker and client. Spring doesn't do anything(Other than when it necessary) but forward the request to the message broker(STOMP messages). The configuration kept on Spring defines couple of important things. One is the exchange and other were routing keys. Spring configuration gives us an abstract layer so we subscribe and push messages to message broker without a fuss.
SimpMessagingTemplate is the abstract layer which we use to communicate with message broker. Spring creates the bean using the given details. Well I couldn't create a instance of SimpMessagingTemplate manually. I have to update Spring 3 application to Spring 4 in order to use websockets.
Since Spring and message broker is decoupled, clustering the application instance doesn't make any effect on message broker. Spring will communicate to message broker only when it need to subscribe to a channel or when it need to publish a message to a channel. So if there is two instances subscribing to same channel it would be two queues binding the one exchange using same routing key. Messages published into a channel will be available to all subscribers(queues) because they all use same routing key. Refer to rabbitmq stop plugin documentation for more elaborative description.
I need a simple web-app in spring-boot that listens for messages on a JMS queue and when arriving it should appear on a webpage via WebSocket.
I have searched for examples and found several individual; either WebSocket or JMS which I have tested on their own but have not succeeded in wiring it together.
I have searched for an example but not found any and in my mind I think it should be pretty easy since it's a very basic requirement.
Do you know about any example with JMS and HTML display via WebSocket that you can share or can give some hints or help for me to solve it?
The Spring Integration comes to the rescue.
You can write <int-jms:message-driven-channel-adapter> to read messages from JMS queue and forward them to the <int-websocket:outbound-channel-adapter>. Where the last one just sends messages to the connected WebSocket session(s).
See these Spring Integration samples on the matter:
https://github.com/spring-projects/spring-integration-samples/tree/master/basic/jms
https://github.com/spring-projects/spring-integration-samples/tree/master/basic/web-sockets
UPDATE
To send the message to all subscribed WebSocket session you should do something like this:
<int:splitter input-channel="enricheMessage" output-channel="sendMessage" apply-sequence="false">
<int-groovy:script>
#serverWebSocketContainer.sessions.keySet().collect {
org.springframework.integration.support.MessageBuilder.withPayload(payload)
.copyHeaders(headers)
.setHeader('simpSessionId', it)
.build()
}
</int-groovy:script>
</int:splitter>
With this Groovy script I retrieve session ids from the serverWebSocketContainer (all those connected clients), iterate over them to build messages to send them over their websocket. And split finally, to send to the <int-websocket:outbound-channel-adapter> one by one.
I need to implement a real-time scenario via web sockets and ZeroMQ queue.
SockJS with Stomp in the client side
Spring MVC / Integration with #EnableWebSocketMessageBroker
Remote messaging queue with ZeroMQ
At this moement, I could connect client and Spring via web sockets but I need to add the magic of remote queues.
ZeroMQ is available from 2 remote URLs (one for publishing and another one for subscribing).
My question is: How can I implement ZeroMQ in order to stay listening subscribed URL or the publishing URL?
Additionally, this type of functionality is conceptually similar to Spring Integration Outbound Gateways which stay listening for the response. Is it possible to implement ZeroMQ via Spring integration?
Thank you
We have an open JIRA issue to add ZeroMQ support to Spring Integration.
But nothing is implemented yet; contributions are welcome!.