I am creating a message bus jar which connects to different MQ broker like Rabbit MQ. The jar will be used by many applications to send and receive message from Rabbit.
While sending message is working as expected from my application, not clear about how to design the listener. Obviously the #RabbitListener is in the jar but I want the message should reach the class in applications.
Any suggestions appreciated.
Is there any better way to create a kind of bus library for rabbit spring and use in applications.
Sounds like you need to make yourself familiar with https://spring.io/projects/spring-integration. And also take a look, please, into this project which already implements something similar: https://spring.io/projects/spring-cloud-bus
Related
I am trying to implement activemq(just want to receive messages) with spring integration.I cant find any clues how to provide java configuration for activemq. What are the minimum required components for job. Somewhere we have channel, adapter somewhere we dont. I am unable to understand spring concepts of adapter, channel and service activator. They are all feeling same to me. I find the integration documentation going above my head. I never had problems with understanding other spring modules(boot, mvc, cloud, batch). Can someone point me in the right direction or what is it that I am doing wrong.
You probably are missing the fact that Spring Integration is a reference implementation for well-known Enterprise Integration Patterns. So, please, consider to start from the theory and ideas. Then you can come back to Spring Integration as an API for those EIP. See respective book on the matter: https://www.enterpriseintegrationpatterns.com.
To read messages from JMS destination you need to use a JmsMessageDrivenEndpoint with respective ConnectionFactory injected.
There is nothing more about that than an ActiveMQConnectionFactory as a bean.
For example in tests we do like this:
new ActiveMQConnectionFactory("vm://localhost?broker.persistent=false")
And an in-memory broker is started.
See a test class with Java DSL for some way how to configure JMS components: https://github.com/spring-projects/spring-integration/blob/master/spring-integration-jms/src/test/java/org/springframework/integration/jms/dsl/JmsTests.java
My requirement is to for starters send a string from one spring-boot application to another using AMQP.
I am new to it and I have gone through this spring-boot guide, so i know the basic fundamentals of Queue, Exchange, Binding, Container and listener.
So, above guide shows the steps when amqp is received in same application.
I am a little confused on where to start if I want to achieve above type of communication between 2 different spring-boot applications.
What are the properties needed for that, etc.
Let me know if any details required.
Just divide the application into two:
One without Receiver and ...
Another without Sender
Make sure your application and configuration etc stays the same. With Spring boot's built-in RabbitMQ, you will be able to run it alright.
Next step is to call sender as and when needed from your business logic.
I want a Java class (jms receiver) which always run in background and check for any message arrive in jms queue.How it can be possible? Please help.
What you want is a JMS MessageListener. Create your JMS client resources (e.g. connection/context, session, etc.) like normal and then invoke setMessageListener on your consumer passing in your implementation of the MessageListener interface. This is pretty basic JMS stuff so you can find more detailed tutorials online.
I' m currently investigation the implementation of queue's or topic, based on activeMQ within our project. The setup is pretty straight forward in which we are using maven modules to seprate business logic according to the business domain. One common module allows us to assemble common logic.
simplified Example:
common module
products module
clients module
One of the requirements is that certain operations are asynchronous towards a backend (by means of a activeMQ) which in turn responds with a result message.
The second requirement is that it should be possible to horizontally scale the application by creating a new deployable artifact with only that module that needs more juice.
We are using spring 4 with of course jms and activeMQ.
On to my question. We would like to use just one queue or topic for backend connectivity. Which would mean our common module would handle jms configuration (jms factory, jms-configuration) and different types of messages will be send over that one queue/topic.
How would can I make sure that product related messages get handled by the "products" module and client related messages get handled by the "clients" module? How can I make sure only one of the "products" modules logic would handle a message if the module was deployed two times? What approach would you recommend or is this one queue/topic "nuts"?
I was myself thinking in the direction of using a topic because of the publ/subsc pattern... , or maybe queue listener acting as publisher in a observer pattern to which product- or client subscribers might subscribe to take over handling the message?
Thanks for your help.
Why using a Topic if you want just one of the "products" modules to handle one message? With Topic you'd have one message - multiple subscribers each getting the message. The Queue ensures only one consumer gets a message (point-to-point), with Topic you'd have one message dispatched to all subscribers.
Regarding the "filtering" of messages, this should be something provider specific. Looking at ActiveMQ docs I see this. So, basically each consumer should get the messages the broker, based on selector, will dispatch. I don't know the specifics, but this would be the first place I would start this investigation.
On the same idea, have a look at this discussion from the Spring forum. It is, indeed, related to Spring Integration, but it's on the same idea of message selection. On the other hand, you could consider adopting Spring Integration in your project: it's kind of an abstraction of integration patterns and fits well with everything message oriented.
Few interesting ideas from that forum post:
JmsTemplate from Spring contains a doReceive method that takes as a parameter a String as message selector
Message selectors are in the JMS spec (scroll down to "Message Properties" section)
Relevant section in the Spring Integration documentation is here
I am trying to implement a point-to-point messaging system using TIBCO EMS and Spring framework.
I am able to write a message to the queue, but the problem I am facing is in consuming the message.
I have written a Java class that implements the Spring DefaultMesssageListener class and used that within the applicationContext.xml file which is as shown below:
For consuming the message I have written a Java class which reads the above applicationContext.xml file. But, when I start the program I am not getting any error but at the same time message is not getting consumed.
Thank you,
Raghu
You missed something important in configuring the queue, the listener, or the client. Review this and see what you missed.