MBeanServerInvocationHandler (Java 2 Platform Ent. Ed. v1.4) - Java Platform, Enterprise Edition v1.4 API Specifications

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Java^TM 2 Platform
Ent. Ed. v1.4

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javax.management
Class MBeanServerInvocationHandler

java.lang.Object
  javax.management.MBeanServerInvocationHandler

All Implemented Interfaces:: InvocationHandler

public class MBeanServerInvocationHandler
extends Object
implements InvocationHandler

InvocationHandler that forwards methods in an MBean's management interface through the MBean server to the MBean.

Given an MBeanServerConnection, the ObjectName of an MBean within that MBean server, and a Java interface Intf that describes the management interface of the MBean using the patterns for a Standard MBean, this class can be used to construct a proxy for the MBean. The proxy implements the interface Intf such that all of its methods are forwarded through the MBean server to the MBean.

If you have an MBean server mbs containing an MBean with ObjectName name, and if the MBean's management interface is described by the Java interface Intf, you can construct a proxy for the MBean like this:

 Intf proxy = (Intf)
     MBeanServerInvocationHandler.newProxyInstance(mbs,
                                                   name,
                                                   Intf.class,
                                                   false);

Suppose, for example, Intf looks like this:

 public interface Intf {
     public String getSomeAttribute();
     public void setSomeAttribute(String value);
     public void someOperation(String param1, int param2);
 }

Then you can execute:

proxy.getSomeAttribute() which will result in a call to mbs.getAttribute(name, "SomeAttribute").
proxy.setSomeAttribute("whatever") which will result in a call to mbs.setAttribute(name, new Attribute("SomeAttribute", "whatever")).
proxy.someOperation("param1", 2) which will be translated into a call to mbs.invoke(name, "someOperation", <etc>).

If the last parameter to newProxyInstance is true, then the MBean is assumed to be a NotificationBroadcaster or NotificationEmitter and the returned proxy will implement NotificationEmitter. A call to NotificationBroadcaster.addNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object) on the proxy will result in a call to MBeanServerConnection.addNotificationListener(ObjectName, NotificationListener, NotificationFilter, Object), and likewise for the other methods of NotificationBroadcaster and NotificationEmitter.

The methods Object.toString(), Object.hashCode(), and Object.equals(Object), when invoked on a proxy using this invocation handler, are forwarded to the MBean server as methods on the proxied MBean. This will only work if the MBean declares those methods in its management interface.

Since:: JMX 1.2

Constructor Summary

MBeanServerInvocationHandler(MBeanServerConnection connection, ObjectName objectName)
          Invocation handler that forwards methods through an MBean server.

Method Summary

Object invoke(Object proxy, Method method, Object[] args)


static Object newProxyInstance(MBeanServerConnection connection, ObjectName objectName, Class interfaceClass, boolean notificationBroadcaster)
          Return a proxy that implements the given interface by forwarding its methods through the given MBean server to the named MBean.

Methods inherited from class java.lang.Object

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

Constructor Detail

MBeanServerInvocationHandler

public MBeanServerInvocationHandler(MBeanServerConnection connection,
                                    ObjectName objectName)

Invocation handler that forwards methods through an MBean server. This constructor may be called instead of relying on newProxyInstance(javax.management.MBeanServerConnection, javax.management.ObjectName, java.lang.Class, boolean), for instance if you need to supply a different ClassLoader to Proxy.newProxyInstance.

Parameters:

connection - the MBean server connection through which all methods of a proxy using this handler will be forwarded.

objectName - the name of the MBean within the MBean server to which methods will be forwarded.

Method Detail

newProxyInstance

public static Object newProxyInstance(MBeanServerConnection connection,
                                      ObjectName objectName,
                                      Class interfaceClass,
                                      boolean notificationBroadcaster)

Return a proxy that implements the given interface by forwarding its methods through the given MBean server to the named MBean.

This method is equivalent to Proxy.newProxyInstance(interfaceClass.getClassLoader(), interfaces, handler). Here handler is the result of new MBeanServerInvocationHandler(connection, objectName), and interfaces is an array that has one element if notificationBroadcaster is false and two if it is true. The first element of interfaces is interfaceClass and the second, if present, is NotificationEmitter.class.

Parameters:: connection - the MBean server to forward to.; objectName - the name of the MBean within connection to forward to.; interfaceClass - the management interface that the MBean exports, which will also be implemented by the returned proxy.; notificationBroadcaster - make the returned proxy implement NotificationEmitter by forwarding its methods via connection.
Returns:: the new proxy instance.

invoke

public Object invoke(Object proxy,
                     Method method,
                     Object[] args)
              throws Throwable

Specified by:: invoke in interface InvocationHandler

Throws:: Throwable