org.apache.ojb.broker.core.proxy
Class VirtualProxy

java.lang.Object
  org.apache.ojb.broker.core.proxy.VirtualProxy

All Implemented Interfaces:

java.io.Serializable

public abstract class VirtualProxy

extends java.lang.Object

implements java.io.Serializable

Proxy base class. can be used to implement lazy materialization techniques.

Version:

$Id: VirtualProxy.java,v 1.1.2.2 2005/01/27 21:18:21 tomdz Exp $

Author:

Thomas Mahler

See Also:

as a sample application., Serialized Form

Constructor Summary

VirtualProxy()
Creates a new, uninitialized proxy.

VirtualProxy(java.lang.reflect.InvocationHandler handler)
Create a VirtualProxy that uses the given invocation handler.

VirtualProxy(PBKey key, Identity oid)
Creates a VirtualProxy for the subject with the given identity.

Method Summary

boolean	alreadyMaterialized() Determines whether this proxy already has been materialized.
static java.lang.Object	createProxy(PBKey key, java.lang.Class proxyClass, Identity realSubjectsIdentity) Creates VirtualProxy instances of a given proxy subclass and the real subject's identity.
static IndirectionHandler	getIndirectionHandler(VirtualProxy proxy) Returns the indirection handler of the given proxy.
java.lang.Object	getRealSubject() Returns the proxies real subject.

Methods inherited from class java.lang.Object

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

Constructor Detail

VirtualProxy

public VirtualProxy()

Creates a new, uninitialized proxy.

VirtualProxy

public VirtualProxy(PBKey key,
                    Identity oid)

Creates a VirtualProxy for the subject with the given identity.

Parameters:

key - The key of the PersistenceBroker

oid - The identity of the subject

VirtualProxy

public VirtualProxy(java.lang.reflect.InvocationHandler handler)

Create a VirtualProxy that uses the given invocation handler. [tomdz] Why here the use of InvocationHandler ?

Parameters:

handler - The indirection handler of the proxy

Method Detail

getIndirectionHandler

public static IndirectionHandler getIndirectionHandler(VirtualProxy proxy)

Returns the indirection handler of the given proxy.

Parameters:

proxy - The proxy

Returns:

The indirection handler

alreadyMaterialized

public boolean alreadyMaterialized()

Determines whether this proxy already has been materialized.

Returns:

true if the real subject already been loaded

createProxy

public static java.lang.Object createProxy(PBKey key,
                                           java.lang.Class proxyClass,
                                           Identity realSubjectsIdentity)

Creates VirtualProxy instances of a given proxy subclass and the real subject's identity.

Parameters:

key - The key of the PersistenceBroker

proxyClass - The Proxy class

realSubjectsIdentity - The identity of the subject

Returns:

An instance of the proxy subclass

Throws:

PersistenceBrokerException - If there is an error creating the proxy object

getRealSubject

public java.lang.Object getRealSubject()
                                throws PersistenceBrokerException

Returns the proxies real subject. The subject will be materialized if necessary.

Returns:

The subject

Throws:

PersistenceBrokerException