Web based Spring example using AMQP

[united123]

Looking for Web based Spring example using AMQP. Need to create a web based app for sending and receiving messages to a user or group of users. Sort of web based chat app.

[Mark Fisher]

I would recommend starting with the Hello World sample from the Spring AMQP project. That exact same code should be able to run within a webapp. You could create a controller that receives an HTTP request (a chat message) and then sends that via AmqpTemplate. On the receiving side, you probably want to have an AJAX client invoking/polling another Controller that contains a Queue of received AMQP Messages.

[Dave Syer]

On the client side there is also the JSON-RPC plugin in the broker (not Spring specificially, but nice to use in JavaScript). Sample: http://dev.rabbitmq.com/www-examples/chat/index.html.

[united123]

Started with using ProducerConfiguration and HelloWorldConfiguration in my spring web app. Got this exception ....am new to AMQP configuration...am missing anything to start with..

SEVERE: StandardWrapper.Throwable
org.springframework.context.ApplicationContextExce ption: Failed to start bean 'messageConfiguration'; nested exception is java.lang.NullPointerException
at org.springframework.context.support.DefaultLifecyc leProcessor.doStart(DefaultLifecycleProcessor.java :169)
at org.springframework.context.support.DefaultLifecyc leProcessor.access$1(DefaultLifecycleProcessor.jav a:154)
at org.springframework.context.support.DefaultLifecyc leProcessor$LifecycleGroup.start(DefaultLifecycleP rocessor.java:335)
at org.springframework.context.support.DefaultLifecyc leProcessor.startBeans(DefaultLifecycleProcessor.j ava:143)
at org.springframework.context.support.DefaultLifecyc leProcessor.onRefresh(DefaultLifecycleProcessor.ja va:108)
at org.springframework.context.support.AbstractApplic ationContext.finishRefresh(AbstractApplicationCont ext.java:908)
at org.springframework.context.support.AbstractApplic ationContext.refresh(AbstractApplicationContext.ja va:428)
at org.springframework.web.servlet.FrameworkServlet.c reateWebApplicationContext(FrameworkServlet.java:4 42)
at org.springframework.web.servlet.FrameworkServlet.c reateWebApplicationContext(FrameworkServlet.java:4 58)
at org.springframework.web.servlet.FrameworkServlet.i nitWebApplicationContext(FrameworkServlet.java:339 )
at org.springframework.web.servlet.FrameworkServlet.i nitServletBean(FrameworkServlet.java:306)
at org.springframework.web.servlet.HttpServletBean.in it(HttpServletBean.java:127)
at javax.servlet.GenericServlet.init(GenericServlet.j ava:212)
at org.apache.catalina.core.StandardWrapper.loadServl et(StandardWrapper.java:1173)
at org.apache.catalina.core.StandardWrapper.load(Stan dardWrapper.java:993)
at org.apache.catalina.core.StandardContext.loadOnSta rtup(StandardContext.java:4149)
at org.apache.catalina.core.StandardContext.start(Sta ndardContext.java:4458)
at org.apache.catalina.core.ContainerBase.start(Conta inerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(Standa rdHost.java:741)
at org.apache.catalina.core.ContainerBase.start(Conta inerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(Stan dardEngine.java:443)
at org.apache.catalina.core.StandardService.start(Sta ndardService.java:516)
at org.apache.catalina.core.StandardServer.start(Stan dardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalin a.java:587)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Native MethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(De legatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootst rap.java:290)
at org.apache.catalina.startup.Bootstrap.main(Bootstr ap.java:415)
Caused by: java.lang.NullPointerException
at org.springframework.amqp.config.AbstractAmqpConfig uration.start(AbstractAmqpConfiguration.java:92)
at org.springframework.context.support.DefaultLifecyc leProcessor.doStart(DefaultLifecycleProcessor.java :166)
... 29 more

[Mark Fisher]

If you don't mind depending on snapshot builds (instead of the milestone1 build), that code has been changed since M1. We're working on the M2 release, and hope to have it relatively soon, but it would be great if your problem is resolved by switching to the snapshot. If it's not resolved, then at least we would know exactly where in the refactored code to track it down.

[united123]

Hey Mark, where can i find the snapshot build.

Thanks

[Mark Fisher]

The nightly builds are uploaded to our snapshot Maven repository. Here's a sample configuration for the <repository> element in the POM:

<repository>
   <id>repository.springframework.maven.snapshot</id>
   <name>Spring Framework Maven Snapshot Repository</name>
   <url>http://maven.springframework.org/snapshot</url>
</repository>

[united123]

What would be the best way for client GUI (Web GUI) to communicate with the message listener to get the message and display in GUI.

I guess we can poll through ajax..any other suggestions..