au.gov.tas.dpiwe.mr.bean
Class NullBean

java.lang.Object
  au.gov.tas.dpiwe.mr.bean.NullBean

All Implemented Interfaces:

SimpleValidator, WrappedBean, ContainerChangeListener, Serializable, EventListener, EnterpriseBean, EntityBean

Direct Known Subclasses:

Artist, Bean, Board, Card, CD, Credit, DebugBean, Deck, Deed, HistoricCommand, MonopolySet, MrSiameseBean, Song, Square, ThinSiameseBean, Token, Track

public abstract class NullBean
extends Object
implements Serializable, ContainerChangeListener, SimpleValidator, WrappedBean

All the methods herein (except containerChanged(), getBeanObject(), throwEJBException() and simpleValidate()) must be provided to implement an entity bean.

However, most container-managed local entity beans won't care about the events these callbacks represent, so null implementations will probably suffice and are provided in this class as a convenience.

Since:

Mr Architecture 1.0

Version:

1.0.0.4

Author:

Kade Hansson

See Also:

Serialized Form

Field Summary

protected Container	container The container associated with this bean.
protected EntityContext	context The entity context associated with this bean.
protected BeanWrapper	wrapper For a cloned bean, contains a reference to the bean wrapper.

Constructor Summary

NullBean()
All entity beans must provide a public no-argument constructor.

Method Summary

Object	clone() Produces a shallow copy of this bean.
void	containerChanged(ContainerChangeEvent event) Event handler called when the ownership of this bean has changed from ClientContainer to ServerContainer or vice versa.
void	ejbActivate() Callback issued upon resurrecting a serialized bean.
void	ejbLoad() Callback issued prior to refreshing a bean with its persistent storage.
void	ejbPassivate() Callback issued prior to serializing a bean.
void	ejbRemove() Callback issued prior to removing a bean from persistent storage.
void	ejbStore() Callback issued prior to committing a bean to persistent storage.
BeanWrapper	getBeanObject() Internal method to determine the bean wrapper associated with this entity bean.
void	setEntityContext(EntityContext context) Callback issued when a bean is placed in a container.
void	simpleValidate() Makes simple data validity checks for this bean based on the MetaData associated with the home.
protected Object	throwEJBException(String message) Utility method to throw an EJB exception with the specified detail message.
void	unsetEntityContext() Callback issued when a bean is removed from a container.

Methods inherited from class java.lang.Object

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

Field Detail

context

protected transient EntityContext context

The entity context associated with this bean. The entity context provides access to the bean's environment.

container

protected transient Container container

The container associated with this bean. Use of this field by beans may impair their operation with containers other than the Mr Architecture Container.

wrapper

protected transient BeanWrapper wrapper

For a cloned bean, contains a reference to the bean wrapper.

Constructor Detail

NullBean

public NullBean()

All entity beans must provide a public no-argument constructor.

Method Detail

ejbActivate

public void ejbActivate()
                 throws RemoteException

Callback issued upon resurrecting a serialized bean.

Specified by:

ejbActivate in interface EntityBean

Throws:

RemoteException - never.

ejbPassivate

public void ejbPassivate()
                  throws RemoteException

Callback issued prior to serializing a bean.

Specified by:

ejbPassivate in interface EntityBean

Throws:

RemoteException - never.

ejbLoad

public void ejbLoad()

Callback issued prior to refreshing a bean with its persistent storage.

Specified by:

ejbLoad in interface EntityBean

ejbStore

public void ejbStore()

Callback issued prior to committing a bean to persistent storage.

Specified by:

ejbStore in interface EntityBean

ejbRemove

public void ejbRemove()

Callback issued prior to removing a bean from persistent storage.

Specified by:

ejbRemove in interface EntityBean

throwEJBException

protected Object throwEJBException(String message)
                            throws EJBException

Utility method to throw an EJB exception with the specified detail message.

Parameters:

message - the detail of what caused the exception.

Returns:

never.

Throws:

EJBException - always.

setEntityContext

public void setEntityContext(EntityContext context)

Callback issued when a bean is placed in a container.

Specified by:

setEntityContext in interface EntityBean

Parameters:

context - provides access to the bean's environment.

unsetEntityContext

public void unsetEntityContext()

Callback issued when a bean is removed from a container.

Specified by:

unsetEntityContext in interface EntityBean

containerChanged

public void containerChanged(ContainerChangeEvent event)

Event handler called when the ownership of this bean has changed from ClientContainer to ServerContainer or vice versa.

Specified by:

containerChanged in interface ContainerChangeListener

Parameters:

event - the event which describes the new container.

getBeanObject

public BeanWrapper getBeanObject()

Internal method to determine the bean wrapper associated with this entity bean.

Specified by:

getBeanObject in interface WrappedBean

Returns:

the bean wrapper, if this bean was originally cloned and has such a wrapper, otherwise null.

simpleValidate

public void simpleValidate()
                    throws ValidateException

Makes simple data validity checks for this bean based on the MetaData associated with the home.

Specified by:

simpleValidate in interface SimpleValidator

Throws:

ValidateException - if the data in this bean is invalid under these checks.

clone

public Object clone()
             throws CloneNotSupportedException

Produces a shallow copy of this bean.

Overrides:

clone in class Object

Returns:

a shallow copy of this bean.

Throws:

CloneNotSupportedException - if this bean does not allow itself to be cloned.