org.springframework.ejb.support
Class AbstractMessageDrivenBean

java.lang.Object
  org.springframework.ejb.support.AbstractMessageDrivenBean

All Implemented Interfaces:

Serializable, EnterpriseBean, MessageDrivenBean

Direct Known Subclasses:

AbstractJmsMessageDrivenBean

public abstract class AbstractMessageDrivenBean
extends Object
implements MessageDrivenBean

Convenient superclass for MDBs. Doesn't require JMS, as EJB 2.1 MDBs are no longer JMS-specific; see the AbstractJmsMessageDrivenBean subclass.

This class ensures that subclasses have access to the MessageDrivenContext provided by the EJB container, and implement a no-arg ejbCreate() method as required by the EJB specification. This ejbCreate() method loads a BeanFactory, before invoking the onEjbCreate() method, which is supposed to contain subclass-specific initialization.

NB: We cannot use final methods to implement EJB API methods, as this violates the EJB specification. However, there should be no need to override the setMessageDrivenContext or ejbCreate() methods.

Author:

Rod Johnson

See Also:

Serialized Form

Field Summary

static String	BEAN_FACTORY_PATH_ENVIRONMENT_KEY
protected Log	logger Logger available to subclasses

Constructor Summary

AbstractMessageDrivenBean()

Method Summary

void	ejbCreate() Lifecycle method required by the EJB specification but not the MessageDrivenBean interface.
void	ejbRemove() EJB lifecycle method, implemented to invoke onEjbRemote and unload the BeanFactory afterwards.
protected BeanFactory	getBeanFactory() May be called after ejbCreate().
protected MessageDrivenContext	getMessageDrivenContext() Convenience method for subclasses to use.
protected abstract void	onEjbCreate() Subclasses must implement this method to do any initialization they would otherwise have done in an ejbCreate() method.
protected void	onEjbRemove() Subclasses must implement this method to do any initialization they would otherwise have done in an ejbRemove() method.
void	setBeanFactoryLocator(BeanFactoryLocator beanFactoryLocator) Set the BeanFactoryLocator to use for this EJB.
void	setBeanFactoryLocatorKey(String factoryKey) Set the bean factory locator key.
void	setMessageDrivenContext(MessageDrivenContext messageDrivenContext) Required lifecycle method.

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.ejb.MessageDrivenBean

ejbRemove

Field Detail

logger

protected final Log logger

Logger available to subclasses

BEAN_FACTORY_PATH_ENVIRONMENT_KEY

public static final String BEAN_FACTORY_PATH_ENVIRONMENT_KEY

See Also:

Constant Field Values

Constructor Detail

AbstractMessageDrivenBean

public AbstractMessageDrivenBean()

Method Detail

setMessageDrivenContext

public void setMessageDrivenContext(MessageDrivenContext messageDrivenContext)

Required lifecycle method. Sets the MessageDriven context.

Specified by:

setMessageDrivenContext in interface MessageDrivenBean

Parameters:

messageDrivenContext - MessageDrivenContext

getMessageDrivenContext

protected final MessageDrivenContext getMessageDrivenContext()

Convenience method for subclasses to use.

Returns:

the MessageDrivenContext passed to this EJB by the EJB container

ejbCreate

public void ejbCreate()

Lifecycle method required by the EJB specification but not the MessageDrivenBean interface. This implementation loads the BeanFactory.

Don't override it (although it can't be made final): code initialization in onEjbCreate(), which is called when the BeanFactory is available.

Unfortunately we can't load the BeanFactory in setSessionContext(), as resource manager access isn't permitted and the BeanFactory may require it.

onEjbCreate

protected abstract void onEjbCreate()

Subclasses must implement this method to do any initialization they would otherwise have done in an ejbCreate() method. In contrast to ejbCreate(), the BeanFactory will have been loaded here.

The same restrictions apply to the work of this method as to an ejbCreate() method.

setBeanFactoryLocator

public void setBeanFactoryLocator(BeanFactoryLocator beanFactoryLocator)

Set the BeanFactoryLocator to use for this EJB. Default is a ContextJndiBeanFactoryLocator.

Can be invoked before loadBeanFactory, for example in constructor or setSessionContext if you want to override the default locator.

Note that the BeanFactory is automatically loaded by the ejbCreate implementations of AbstractStatelessSessionBean and AbstractMessageDriverBean but needs to be explicitly loaded in custom AbstractStatefulSessionBean ejbCreate methods.

See Also:

AbstractStatelessSessionBean.ejbCreate(), ejbCreate(), AbstractStatefulSessionBean.loadBeanFactory(), ContextJndiBeanFactoryLocator

setBeanFactoryLocatorKey

public void setBeanFactoryLocatorKey(String factoryKey)

Set the bean factory locator key.

In case of the default BeanFactoryLocator implementation, ContextJndiBeanFactoryLocator, this is the JNDI path. The default value of this property is "java:comp/env/ejb/BeanFactoryPath".

Can be invoked before loadBeanFactory, for example in constructor or setSessionContext if you want to override the default locator key.

See Also:

BEAN_FACTORY_PATH_ENVIRONMENT_KEY

getBeanFactory

protected BeanFactory getBeanFactory()

May be called after ejbCreate().

Returns:

the bean factory

ejbRemove

public void ejbRemove()

EJB lifecycle method, implemented to invoke onEjbRemote and unload the BeanFactory afterwards.

Don't override it (although it can't be made final): code your shutdown in onEjbRemove.

See Also:

onEjbRemove()

onEjbRemove

protected void onEjbRemove()

Subclasses must implement this method to do any initialization they would otherwise have done in an ejbRemove() method. The BeanFactory will be unloaded afterwards.

This implementation is empty, to be overridden in subclasses. The same restrictions apply to the work of this method as to an ejbRemove() method.