API java : RemoteObjectInvocationHandler

java.rmi.server
Class RemoteObjectInvocationHandler

java.lang.Object
  java.rmi.server.RemoteObject
      java.rmi.server.RemoteObjectInvocationHandler

All Implemented Interfaces:

Serializable, InvocationHandler, Remote

public class RemoteObjectInvocationHandler
extends RemoteObject
implements InvocationHandler

An implementation of the InvocationHandler interface for use with Java Remote Method Invocation (Java RMI). This invocation handler can be used in conjunction with a dynamic proxy instance as a replacement for a pregenerated stub class.

Applications are not expected to use this class directly. A remote object exported to use a dynamic proxy with UnicastRemoteObject or Activatable has an instance of this class as that proxy's invocation handler.

Since:

1.5

See Also:

Serialized Form

Field Summary

 

Fields inherited from class java.rmi.server.RemoteObject
ref

 

Constructor Summary
RemoteObjectInvocationHandler(RemoteRef ref)           Creates a new RemoteObjectInvocationHandler constructed with the specified RemoteRef.

 

Method Summary
Object	invoke(Object proxy, Method method, Object[] args)           Processes a method invocation made on the encapsulating proxy instance, proxy, and returns the result.

 

Methods inherited from class java.rmi.server.RemoteObject
equals, getRef, hashCode, toString, toStub

 

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

 

Constructor Detail

RemoteObjectInvocationHandler

public RemoteObjectInvocationHandler(RemoteRef ref)

Creates a new RemoteObjectInvocationHandler constructed with the specified RemoteRef.

Parameters:

ref - the remote ref

Throws:

NullPointerException - if ref is null

invoke

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

Processes a method invocation made on the encapsulating proxy instance, proxy, and returns the result.

RemoteObjectInvocationHandler implements this method as follows:

If method is one of the following methods, it is processed as described below:

• Object.hashCode: Returns the hash code value for the proxy.
• Object.equals: Returns true if the argument (args[0]) is an instance of a dynamic proxy class and this invocation handler is equal to the invocation handler of that argument, and returns false otherwise.
• Object.toString: Returns a string representation of the proxy.

Otherwise, a remote call is made as follows:

• If proxy is not an instance of the interface Remote, then an IllegalArgumentException is thrown.
• Otherwise, the invoke method is invoked on this invocation handler's RemoteRef, passing proxy, method, args, and the method hash (defined in section 8.3 of the "Java Remote Method Invocation (RMI) Specification") for method, and the result is returned.
• If an exception is thrown by RemoteRef.invoke and that exception is a checked exception that is not assignable to any exception in the throws clause of the method implemented by the proxy's class, then that exception is wrapped in an UnexpectedException and the wrapped exception is thrown. Otherwise, the exception thrown by invoke is thrown by this method.

The semantics of this method are unspecified if the arguments could not have been produced by an instance of some valid dynamic proxy class containing this invocation handler.

Specified by:

invoke in interface InvocationHandler

Parameters:

proxy - the proxy instance that the method was invoked on

method - the Method instance corresponding to the interface method invoked on the proxy instance

args - an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if the method takes no arguments

Returns:

the value to return from the method invocation on the proxy instance

Throws:

Throwable - the exception to throw from the method invocation on the proxy instance

See Also: