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

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

All Implemented Interfaces:

Serializable, IndirectionHandler

Direct Known Subclasses:

IndirectionHandlerCGLIBImpl, IndirectionHandlerJDKImpl

public abstract class AbstractIndirectionHandler
extends Object
implements IndirectionHandler

Abstract implementation for the indirection handler used by ojb's proxies.

Version:

$Id: AbstractIndirectionHandler.java,v 1.1 2007-08-24 22:17:32 ewestfal Exp $

See Also:

Serialized Form

Constructor Summary

AbstractIndirectionHandler(PBKey brokerKey, Identity id)
Creates a new indirection handler for the indicated object.

Method Summary

void	addListener(MaterializationListener listener) Adds a materialization listener.
protected void	afterMaterialization() Calls afterMaterialization on all registered listeners in the reverse order of registration.
boolean	alreadyMaterialized() Determines whether the real subject already has been materialized.
protected void	beforeMaterialization() Calls beforeMaterialization on all registered listeners in the reverse order of registration.
protected org.apache.ojb.broker.core.proxy.AbstractIndirectionHandler.TemporaryBrokerWrapper	getBroker() Gets the persistence broker used by this indirection handler.
PBKey	getBrokerKey() Returns the key of the persistence broker used by this indirection handler.
Identity	getIdentity() Returns the identity of the subject.
Object	getRealSubject() Returns the proxies real subject.
Object	invoke(Object proxy, Method method, Object[] args) [Copied from InvocationHandler]: Processes a method invocation on a proxy instance and returns the result.
protected Object	materializeSubject() Retrieves the real subject from the underlying RDBMS.
void	removeListener(MaterializationListener listener) Removes a materialization listener.
protected void	setBrokerKey(PBKey brokerKey) Sets the key of the persistence broker used by this indirection handler.
protected void	setIdentity(Identity identity) Sets the identity of the subject of this indirection handler.
void	setRealSubject(Object object) [olegnitz] This looks stupid, but is really necessary for OTM: the materialization listener replaces the real subject by its clone to ensure transaction isolation.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractIndirectionHandler

public AbstractIndirectionHandler(PBKey brokerKey,
                                  Identity id)

Creates a new indirection handler for the indicated object.

Parameters:

brokerKey - The key of the persistence broker

id - The identity of the subject

Method Detail

getIdentity

public Identity getIdentity()

Returns the identity of the subject.

Specified by:

getIdentity in interface IndirectionHandler

Returns:

The identity

setIdentity

protected void setIdentity(Identity identity)

Sets the identity of the subject of this indirection handler.

Parameters:

identity -

getBrokerKey

public PBKey getBrokerKey()

Returns the key of the persistence broker used by this indirection handler.

Specified by:

getBrokerKey in interface IndirectionHandler

Returns:

The broker key

setBrokerKey

protected void setBrokerKey(PBKey brokerKey)

Sets the key of the persistence broker used by this indirection handler.

Parameters:

brokerKey - The broker key

addListener

public void addListener(MaterializationListener listener)

Adds a materialization listener.

Specified by:

addListener in interface IndirectionHandler

Parameters:

listener - The listener to add

removeListener

public void removeListener(MaterializationListener listener)

Removes a materialization listener.

Specified by:

removeListener in interface IndirectionHandler

Parameters:

listener - The listener to remove

beforeMaterialization

protected void beforeMaterialization()

Calls beforeMaterialization on all registered listeners in the reverse order of registration.

afterMaterialization

protected void afterMaterialization()

Calls afterMaterialization on all registered listeners in the reverse order of registration.

getBroker

protected org.apache.ojb.broker.core.proxy.AbstractIndirectionHandler.TemporaryBrokerWrapper getBroker()
                                                                                                throws PBFactoryException

Gets the persistence broker used by this indirection handler. If no PBKey is available a runtime exception will be thrown.

Returns:

a PersistenceBroker

Throws:

PBFactoryException

invoke

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

[Copied from InvocationHandler]:
Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with.

Specified by:

invoke in interface IndirectionHandler

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. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.

args - An array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

Returns:

The value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is null and the interface method's return type is primitive, then a NullPointerException will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a ClassCastException will be thrown by the method invocation on the proxy instance.

Throws:

PersistenceBrokerException - The exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the throws clause of the interface method or to the unchecked exception types java.lang.RuntimeException or java.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the throws clause of the interface method, then an UndeclaredThrowableException containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

See Also:

UndeclaredThrowableException

getRealSubject

public Object getRealSubject()
                      throws PersistenceBrokerException

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

Specified by:

getRealSubject in interface IndirectionHandler

Returns:

The subject

Throws:

PersistenceBrokerException

setRealSubject

public void setRealSubject(Object object)

[olegnitz] This looks stupid, but is really necessary for OTM: the materialization listener replaces the real subject by its clone to ensure transaction isolation. Is there a better way to do this?

Specified by:

setRealSubject in interface IndirectionHandler

materializeSubject

protected Object materializeSubject()
                             throws PersistenceBrokerException

Retrieves the real subject from the underlying RDBMS. Override this method if the object is to be materialized in a specific way.

Returns:

The real subject of the proxy

Throws:

PersistenceBrokerException

alreadyMaterialized

public boolean alreadyMaterialized()

Determines whether the real subject already has been materialized.

Specified by:

alreadyMaterialized in interface IndirectionHandler

Returns:

true if the real subject has already been loaded