I wanted to expose mbeans related to application monitoring and services such as a JMS broker, users in session, etc and remote that data to the client which in my case was Flex.  First I checked out using annotations for automated registration and mbean creation but that wouldn’t help me export to a remoting format..without creating my own classes. Something for another post, but what I did was create a package with some classes, which I will explain here. You can certainly deliver this strategy more minimally but I’ve found that to come back and bite me later so I’ve added in some type safety to the proxy creation of the MBeans.

The Basic Components There are a few important components you need to set this up as a framework 1. An MBeanConnection 2. A type-safe proxy generator 3. An applicable JMX service URL, Port, Hostname To export mbeans to the client 1. ObjectName that can be connected to if they are services 2. Ports for those services where applicable (i.e. a broker) 3. Interfaces to proxy I. The Goal: export mbean data by remoting to the client I created a service which is mirrored as a Flex actionscript class for remoting which encapsulates the calls for various system monitoring data via jmx: This I registered for remoting in the framework of choice, in my case it was Flex. I have a custom annotation that handles this which I don’t include in this snippet. public class ClientMBeanService implements IClientMBeanService { ..view the code… } II. The Delegate With the idea of each component to be exported create a Delegate class that implements the interface dictating the contract that it must implement a method to provide the port, the ObjectName and export the mbean: public class BrokerDelegate implements IMBeanDelegate { ..view the code… } All Delegates must implement public interface IMBeanDelegate { ..view the code… } III. For Remote and Local MBeanConnections public class MBeanConnection { ..view the code… } IV. The Cool Part: Get a Typesafe Proxy Intance of The MBean public final class MBeanProxyInstance { ..view the code… } V. Typesafing: I did not originally write this class, only modified it for Java 6, but the crux is: public class TypeSafeMBeanProxy { ..view the code… }

If you just want to easily export mbeans to jconsole or an external profiling tool this is pretty sweet:

I. Create a Spring schema config file for JMX

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

<!-- This bean needs to be eagerly pre-instantiated in order for the exporting to occur: -->
<!-- ***************** Autodetects Annotated Beans JMX Exposure *********************** -->
<bean id="annotationalMbeanExporter" class="org.springframework.jmx.export.MBeanExporter" lazy-init="false">
<property name="autodetect" value="true"/>
<property name="namingStrategy" ref="namingStrategy"/>
<property name="assembler" ref="assembler"/>
<!-- one of many optional config options -->
<property name="registrationBehaviorName" value="REGISTRATION_IGNORE_EXISTING"/>
</bean>
<bean id="attributeSource" class="org.springframework.jmx.export.annotation.AnnotationJmxAttributeSource"/>
<bean id="assembler" class="org.springframework.jmx.export.assembler.MetadataMBeanInfoAssembler">
<property name="attributeSource" ref="attributeSource"/>
</bean>
<bean id="namingStrategy" class="org.springframework.jmx.export.naming.MetadataNamingStrategy">
<property name="attributeSource" ref="attributeSource"/>
</bean>
</beans>

II. Annotate a component, bean, etc

@Service
@ManagedResource(objectName = "bean:name=applicationMonitor")
public class ClientMBeanService implements IClientMBeanService {

@ManagedOperation(description = "Monitor the JMS broker")
public BrokerStatistics exposeBroker() {
return new BrokerDelegate().exposeMBean();
}
}

@Component
@ManagedResource(objectName = "spring:name=broker", description = "ActimemMQ Broker")
public class BrokerStatistics {

private String brokerId;
private String brokerName;
private long totalMessages;
private long totalConsumers;
private long totalTopics;
private long totalQueues;
private List<Map> topics;
private List<Map> queues;

@ManagedAttribute
public String getBrokerId() {
return brokerId;
}
...etc
}

The annotational configuration in the mbean exporter allows automatic registration and mbean creation of beans. It’s that simple.