javax.management
Class MBeanServerInvocationHandler

java.lang.Object
  extended by javax.management.MBeanServerInvocationHandler
All Implemented Interfaces:
InvocationHandler

public class MBeanServerInvocationHandler
extends Object
implements InvocationHandler

Provides a proxy for a management bean. The methods of the given interface are fulfilled by redirecting the calls over an MBeanServerConnection to the bean specified by the supplied ObjectName.

The InvocationHandler also makes provision for MXBeans by providing type conversion according to the rules defined for these beans. The input parameters are converted to their equivalent open type before calling the method, and then the return value is converted back from its open type to the appropriate Java type. For example, a method that takes an Enum as input and returns a List will have the input value converted from an Enum to a String, while the return value will be converted from its return type (an appropriately typed array) to a List.

The proxy has special cases for the Object.equals(Object), Object.hashCode() and Object.toString() methods. Unless they are specified explictly by the interface, the following behaviour is provided for these methods by the proxy:

Since:
1.5

Constructor Summary
MBeanServerInvocationHandler(MBeanServerConnection conn, ObjectName name)
          Constructs a new MBeanServerInvocationHandler which forwards methods to the supplied bean via the given MBeanServerConnection.
MBeanServerInvocationHandler(MBeanServerConnection conn, ObjectName name, boolean mxBean)
          Constructs a new MBeanServerInvocationHandler which forwards methods to the supplied bean via the given MBeanServerConnection.
 
Method Summary
 MBeanServerConnection getMBeanServerConnection()
          Returns the connection through which the calls to the bean will be made.
 ObjectName getObjectName()
          Returns the name of the bean to which method calls are made.
 Object invoke(Object proxy, Method method, Object[] args)
          Called by the proxy class whenever a method is called.
 boolean isMXBean()
          Returns true if this is a proxy for an MXBean and conversions must be applied to input parameters and return types, according to the rules for such beans.
static
<T> T
newProxyInstance(MBeanServerConnection conn, ObjectName name, Class<T> iface, boolean broadcaster)
           Returns a proxy for the specified bean.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MBeanServerInvocationHandler

public MBeanServerInvocationHandler(MBeanServerConnection conn,
                                    ObjectName name)
Constructs a new MBeanServerInvocationHandler which forwards methods to the supplied bean via the given MBeanServerConnection. This constructor is used in preference to JMX#newMBeanProxy(MBeanServerConnection, ObjectName, Class) if you wish to make your own call to java.lang.reflect.Proxy#newInstance(ClassLoader, Class[], java.lang.reflect.InvocationHandler) with a different ClassLoader. Calling this constructor is equivalent to MBeanServerInvocationHandler(conn, name, false). The other constructor should be used instead if the bean being proxied is an MXBean.

Parameters:
conn - the connection through which methods will be forwarded to the bean.
name - the name of the bean to use to provide the actual calls.

MBeanServerInvocationHandler

public MBeanServerInvocationHandler(MBeanServerConnection conn,
                                    ObjectName name,
                                    boolean mxBean)
Constructs a new MBeanServerInvocationHandler which forwards methods to the supplied bean via the given MBeanServerConnection. This constructor is used in preference to JMX#newMBeanProxy(MBeanServerConnection, ObjectName, Class) if you wish to make your own call to java.lang.reflect.Proxy#newInstance(ClassLoader, Class[], java.lang.reflect.InvocationHandler) with a different ClassLoader.

Parameters:
conn - the connection through which methods will be forwarded to the bean.
name - the name of the bean to use to provide the actual calls.
mxBean - true if the bean being proxied is an MXBean.
Since:
1.6
Method Detail

getMBeanServerConnection

public MBeanServerConnection getMBeanServerConnection()
Returns the connection through which the calls to the bean will be made.

Returns:
the connection being used to forward the calls to the bean.
Since:
1.6

getObjectName

public ObjectName getObjectName()
Returns the name of the bean to which method calls are made.

Returns:
the bean which provides the actual method calls.
Since:
1.6

invoke

public Object invoke(Object proxy,
                     Method method,
                     Object[] args)
              throws Throwable
Called by the proxy class whenever a method is called. The method is emulated by retrieving an attribute from, setting an attribute on or invoking a method on the server connection as required. Translation between the Java data types supplied as arguments to the open types used by the bean is provided, as well as translation of the return value back in to the appropriate Java type if the bean is an MXBean.

Specified by:
invoke in interface InvocationHandler
Parameters:
proxy - the proxy on which the method was called.
method - the method which was called.
args - the arguments supplied to the method.
Returns:
the return value from the method.
Throws:
Throwable - if an exception is thrown in performing the method emulation.
See Also:
Proxy, UndeclaredThrowableException

isMXBean

public boolean isMXBean()
Returns true if this is a proxy for an MXBean and conversions must be applied to input parameters and return types, according to the rules for such beans.

Returns:
true if this is a proxy for an MXBean.
Since:
1.6

newProxyInstance

public static <T> T newProxyInstance(MBeanServerConnection conn,
                                     ObjectName name,
                                     Class<T> iface,
                                     boolean broadcaster)

Returns a proxy for the specified bean. A proxy object is created using Proxy.newProxyInstance(iface.getClassLoader(), new Class[] { iface }, handler). The NotificationEmitter class is included as the second element of the array if broadcaster is true. handler refers to the invocation handler which forwards calls to the connection, which is created by a call to new MBeanServerInvocationHandler(conn, name).

Note: use of the proxy may result in IOExceptions from the underlying MBeanServerConnection. As of 1.6, the use of JMX.newMBeanProxy(MBeanServerConnection, ObjectName,Class) and JMX.newMBeanProxy(MBeanServerConnection, ObjectName,Class,boolean) is preferred.

Parameters:
conn - the server connection to use to access the bean.
name - the ObjectName of the bean to provide a proxy for.
iface - the interface for the bean being proxied.
broadcaster - true if the proxy should implement NotificationEmitter.
Returns:
a proxy for the specified bean.
See Also:
JMX.newMBeanProxy(MBeanServerConnection,ObjectName,Class)