com.bigdata.jmx

Class JMXTest

java.lang.Object

com.bigdata.jmx.JMXTest

public class JMXTest
extends Object

Class demonstrates the ability to declare get/set and get methods on the the JMXTest.IFoo interface and expose a JMXTest.Foo implementation of that interface as a StandardMBean. You can run main(String[]) and start jconsole and inspect/set the "foo" attribute and see the change on the read-only "bar" attribute. No fuss, no muss.

There are some caveats. In general, you can declare interfaces having getters and directly expose the services implementing those interfaces as MBeans. If the service supports a dynamic change to the value of an attribute, then you can also put the settor on the interface to be exposed as an MBean.

The get/set methods need to be synchronized so that changes made by a setter will become immediately visible to other code also synchronized on the same reference. If the service internally uses the getter, then consider having district objects on which you synchronize for get() methods which are heavily used in order to minimize contention for the object's monitor. The other option is to make the field for the attribute volatile.

Since MBean methods do not declare RMI exceptions there can be a conflict in the interface if the method is also exposed for RMI, e.g., for a jini-based service. You need to have two interfaces for this case.

There may be some cases where an attribute needs to be broken into a current value and a target value, much like adjusting clocks to network time.

Version:

$Id$

Author:

Bryan Thompson

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JMXTest.Clock
static class	JMXTest.Foo Object implementing that interface.
static interface	JMXTest.IClock
static interface	JMXTest.IFoo Interface to be exposed as an MBean.

Constructor Summary

Constructors

Constructor and Description
JMXTest()

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(String[] args) When you run this class it registers an instance of JMXTest.Foo as an MBean and then waits forever.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JMXTest

public JMXTest()

Method Detail

main

public static void main(String[] args)
                 throws InstanceAlreadyExistsException,
                        MBeanRegistrationException,
                        NotCompliantMBeanException,
                        MalformedObjectNameException,
                        NullPointerException,
                        InterruptedException

When you run this class it registers an instance of JMXTest.Foo as an MBean and then waits forever. You can run jconsole and verify that you can see the MBean and its attributes and change attribute values using the setter(s) declared on the JMXTest.IFoo interface.

Parameters:

args - Not used.

Throws:

InstanceAlreadyExistsException

MBeanRegistrationException

NotCompliantMBeanException

MalformedObjectNameException

NullPointerException

InterruptedException