org.springframework.ejb.access

Class LocalStatelessSessionProxyFactoryBean

java.lang.Object

org.springframework.jndi.JndiAccessor

org.springframework.jndi.JndiLocatorSupport

org.springframework.jndi.JndiObjectLocator

org.springframework.ejb.access.AbstractSlsbInvokerInterceptor

org.springframework.ejb.access.LocalSlsbInvokerInterceptor

org.springframework.ejb.access.LocalStatelessSessionProxyFactoryBean

All Implemented Interfaces:

Aware, BeanClassLoaderAware, FactoryBean<java.lang.Object>, InitializingBean

public class LocalStatelessSessionProxyFactoryBean
extends LocalSlsbInvokerInterceptor
implements FactoryBean<java.lang.Object>, BeanClassLoaderAware

Convenient FactoryBean for local Stateless Session Bean (SLSB) proxies. Designed for EJB 2.x, but works for EJB 3 Session Beans as well.

See JndiObjectLocator for info on how to specify the JNDI location of the target EJB.

If you want control over interceptor chaining, use an AOP ProxyFactoryBean with LocalSlsbInvokerInterceptor rather than rely on this class.

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).

Since:

09.05.2003

Author:

Rod Johnson, Colin Sampaleanu

See Also:

AbstractSlsbInvokerInterceptor.setLookupHomeOnStartup(boolean), AbstractSlsbInvokerInterceptor.setCacheHome(boolean)

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.ClassLoader	beanClassLoader
private java.lang.Class<?>	businessInterface The business interface of the EJB we're proxying
private java.lang.Object	proxy EJBLocalObject

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
LocalStatelessSessionProxyFactoryBean()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet() Fetches EJB home on startup, if necessary.
java.lang.Class<?>	getBusinessInterface() Return the business interface of the EJB we're proxying.
java.lang.Object	getObject() Return an instance (possibly shared or independent) of the object managed by this factory.
java.lang.Class<?>	getObjectType() Return the type of object that this FactoryBean creates, or null if not known in advance.
boolean	isSingleton() Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?
void	setBeanClassLoader(java.lang.ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.
void	setBusinessInterface(java.lang.Class<?> businessInterface) Set the business interface of the EJB we're proxying.

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

getCreateMethod, getSessionBeanInstance, invokeInContext, newSessionBeanInstance, releaseSessionBeanInstance, removeSessionBeanInstance

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

create, getHome, invoke, isHomeRefreshable, refreshHome, setCacheHome, setExposeAccessContext, setLookupHomeOnStartup

Methods inherited from class org.springframework.jndi.JndiObjectLocator

getExpectedType, getJndiName, lookup, 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

businessInterface

private java.lang.Class<?> businessInterface

The business interface of the EJB we're proxying

beanClassLoader

private java.lang.ClassLoader beanClassLoader

proxy

private java.lang.Object proxy

EJBLocalObject

Constructor Detail

LocalStatelessSessionProxyFactoryBean

public LocalStatelessSessionProxyFactoryBean()

Method Detail

setBusinessInterface

public void setBusinessInterface(java.lang.Class<?> businessInterface)

Set the business interface of the EJB we're proxying. This will normally be a super-interface of the EJB local component interface. Using a business methods interface is a best practice when implementing EJBs.

Parameters:

businessInterface - set the business interface of the EJB

getBusinessInterface

public java.lang.Class<?> getBusinessInterface()

Return the business interface of the EJB we're proxying.

setBeanClassLoader

public void setBeanClassLoader(java.lang.ClassLoader classLoader)

Description copied from interface: BeanClassLoaderAware

Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

Specified by:

setBeanClassLoader in interface BeanClassLoaderAware

Parameters:

classLoader - the owning class loader; may be null in which case a default ClassLoader must be used, for example the ClassLoader obtained via ClassUtils.getDefaultClassLoader()

afterPropertiesSet

public void afterPropertiesSet()
                        throws javax.naming.NamingException

Description copied from class: AbstractSlsbInvokerInterceptor

Fetches EJB home on startup, if necessary.

Specified by:

afterPropertiesSet in interface InitializingBean

Overrides:

afterPropertiesSet in class AbstractSlsbInvokerInterceptor

Throws:

javax.naming.NamingException

See Also:

AbstractSlsbInvokerInterceptor.setLookupHomeOnStartup(boolean), AbstractSlsbInvokerInterceptor.refreshHome()

getObject

public java.lang.Object getObject()

Description copied from interface: FactoryBean

Return an instance (possibly shared or independent) of the object managed by this factory.

As with a BeanFactory, this allows support for both the Singleton and Prototype design pattern.

If this FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding FactoryBeanNotInitializedException.

As of Spring 2.0, FactoryBeans are allowed to return null objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

Specified by:

getObject in interface FactoryBean<java.lang.Object>

Returns:

an instance of the bean (can be null)

See Also:

FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<?> getObjectType()

Description copied from interface: FactoryBean

Return the type of object that this FactoryBean creates, or null if not known in advance.

This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Specified by:

getObjectType in interface FactoryBean<java.lang.Object>

Returns:

the type of object that this FactoryBean creates, or null if not known at the time of the call

See Also:

ListableBeanFactory.getBeansOfType(java.lang.Class<T>)

isSingleton

public boolean isSingleton()

Description copied from interface: FactoryBean

Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its SmartFactoryBean.isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

Specified by:

isSingleton in interface FactoryBean<java.lang.Object>

Returns:

whether the exposed object is a singleton

See Also:

FactoryBean.getObject(), SmartFactoryBean.isPrototype()