org.springframework.ejb.access

Class SimpleRemoteSlsbInvokerInterceptor

java.lang.Object

org.springframework.jndi.JndiAccessor

org.springframework.jndi.JndiLocatorSupport

org.springframework.jndi.JndiObjectLocator

org.springframework.ejb.access.AbstractSlsbInvokerInterceptor

org.springframework.ejb.access.AbstractRemoteSlsbInvokerInterceptor

org.springframework.ejb.access.SimpleRemoteSlsbInvokerInterceptor

All Implemented Interfaces:

DisposableBean, InitializingBean

Direct Known Subclasses:

SimpleRemoteStatelessSessionProxyFactoryBean

public class SimpleRemoteSlsbInvokerInterceptor
extends AbstractRemoteSlsbInvokerInterceptor
implements DisposableBean

Basic invoker for a remote Stateless Session Bean. Designed for EJB 2.x, but works for EJB 3 Session Beans as well.

"Creates" a new EJB instance for each invocation, or caches the session bean instance for all invocations (see setCacheSessionBean(boolean)). See JndiObjectLocator for info on how to specify the JNDI location of the target EJB.

In a bean container, this class is normally best used as a singleton. However, if that bean container pre-instantiates singletons (as do the XML ApplicationContext variants) you may have a problem if the bean container is loaded before the EJB container loads the target EJB. That is because by default the JNDI lookup will be performed in the init method of this class and cached, but the EJB will not have been bound at the target location yet. The best solution is to set the "lookupHomeOnStartup" property to "false", in which case the home will be fetched on first access to the EJB. (This flag is only true by default for backwards compatibility reasons).

This invoker is typically used with an RMI business interface, which serves as super-interface of the EJB component interface. Alternatively, this invoker can also proxy a remote SLSB with a matching non-RMI business interface, i.e. an interface that mirrors the EJB business methods but does not declare RemoteExceptions. In the latter case, RemoteExceptions thrown by the EJB stub will automatically get converted to Spring's unchecked RemoteAccessException.

Since:

09.05.2003

Author:

Rod Johnson, Juergen Hoeller

See Also:

RemoteAccessException, AbstractSlsbInvokerInterceptor.setLookupHomeOnStartup(boolean), AbstractSlsbInvokerInterceptor.setCacheHome(boolean), AbstractRemoteSlsbInvokerInterceptor.setRefreshHomeOnConnectFailure(boolean)

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.Object	beanInstance
private java.lang.Object	beanInstanceMonitor
private boolean	cacheSessionBean

Fields inherited from class org.springframework.jndi.JndiLocatorSupport

CONTAINER_PREFIX

Fields inherited from class org.springframework.jndi.JndiAccessor

logger

Constructor Summary

Constructors

Constructor and Description
SimpleRemoteSlsbInvokerInterceptor()

Method Summary

Modifier and Type	Method and Description
void	destroy() Remove the cached session bean instance, if necessary.
protected java.lang.Object	doInvoke(MethodInvocation invocation) This implementation "creates" a new EJB instance for each invocation.
protected java.lang.Object	getSessionBeanInstance() Return an EJB component instance to delegate the call to.
protected void	refreshHome() Reset the cached session bean instance, if necessary.
protected void	releaseSessionBeanInstance(EJBObject ejb) Release the given EJB instance.
void	setCacheSessionBean(boolean cacheSessionBean) Set whether to cache the actual session bean object.

Methods inherited from class org.springframework.ejb.access.AbstractRemoteSlsbInvokerInterceptor

getCreateMethod, invokeInContext, isConnectFailure, isHomeRefreshable, lookup, newSessionBeanInstance, refreshAndRetry, removeSessionBeanInstance, setHomeInterface, setRefreshHomeOnConnectFailure

Methods inherited from class org.springframework.ejb.access.AbstractSlsbInvokerInterceptor

afterPropertiesSet, create, getHome, invoke, setCacheHome, setExposeAccessContext, setLookupHomeOnStartup

Methods inherited from class org.springframework.jndi.JndiObjectLocator

getExpectedType, getJndiName, setExpectedType, setJndiName

Methods inherited from class org.springframework.jndi.JndiLocatorSupport

convertJndiName, isResourceRef, lookup, lookup, setResourceRef

Methods inherited from class org.springframework.jndi.JndiAccessor

getJndiEnvironment, getJndiTemplate, setJndiEnvironment, setJndiTemplate

Methods inherited from class java.lang.Object

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

Field Detail

cacheSessionBean

private boolean cacheSessionBean

beanInstance

private java.lang.Object beanInstance

beanInstanceMonitor

private final java.lang.Object beanInstanceMonitor

Constructor Detail

SimpleRemoteSlsbInvokerInterceptor

public SimpleRemoteSlsbInvokerInterceptor()

Method Detail

setCacheSessionBean

public void setCacheSessionBean(boolean cacheSessionBean)

Set whether to cache the actual session bean object.

Off by default for standard EJB compliance. Turn this flag on to optimize session bean access for servers that are known to allow for caching the actual session bean object.

See Also:

AbstractSlsbInvokerInterceptor.setCacheHome(boolean)

doInvoke

protected java.lang.Object doInvoke(MethodInvocation invocation)
                             throws java.lang.Throwable

This implementation "creates" a new EJB instance for each invocation. Can be overridden for custom invocation strategies.

Alternatively, override getSessionBeanInstance() and releaseSessionBeanInstance(EJBObject) to change EJB instance creation, for example to hold a single shared EJB component instance.

Specified by:

doInvoke in class AbstractRemoteSlsbInvokerInterceptor

Parameters:

invocation - the AOP method invocation

Returns:

the invocation result, if any

Throws:

java.lang.Throwable - in case of invocation failure

See Also:

AbstractSlsbInvokerInterceptor.getHome(), AbstractRemoteSlsbInvokerInterceptor.newSessionBeanInstance()

getSessionBeanInstance

protected java.lang.Object getSessionBeanInstance()
                                           throws javax.naming.NamingException,
                                                  java.lang.reflect.InvocationTargetException

Return an EJB component instance to delegate the call to.

The default implementation delegates to AbstractRemoteSlsbInvokerInterceptor.newSessionBeanInstance().

Returns:

the EJB component instance

Throws:

javax.naming.NamingException - if thrown by JNDI

java.lang.reflect.InvocationTargetException - if thrown by the create method

See Also:

AbstractRemoteSlsbInvokerInterceptor.newSessionBeanInstance()

releaseSessionBeanInstance

protected void releaseSessionBeanInstance(EJBObject ejb)

Release the given EJB instance.

The default implementation delegates to AbstractRemoteSlsbInvokerInterceptor.removeSessionBeanInstance(EJBObject).

Parameters:

ejb - the EJB component instance to release

See Also:

AbstractRemoteSlsbInvokerInterceptor.removeSessionBeanInstance(EJBObject)

refreshHome

protected void refreshHome()
                    throws javax.naming.NamingException

Reset the cached session bean instance, if necessary.

Overrides:

refreshHome in class AbstractSlsbInvokerInterceptor

Throws:

javax.naming.NamingException - if thrown by the JNDI lookup

See Also:

JndiObjectLocator.lookup(), AbstractSlsbInvokerInterceptor.getCreateMethod(java.lang.Object)

destroy

public void destroy()

Remove the cached session bean instance, if necessary.

Specified by:

destroy in interface DisposableBean