org.springframework.web.context.support
Class ServletContextAttributeFactoryBean

java.lang.Object
  org.springframework.web.context.support.ServletContextAttributeFactoryBean

All Implemented Interfaces:

FactoryBean, ServletContextAware

public class ServletContextAttributeFactoryBean
extends Object
implements FactoryBean, ServletContextAware

FactoryBean that fetches a specific, existing ServletContext attribute. Exposes that ServletContext attribute when used as bean reference, effectively making it available as named Spring bean instance.

Intended to link in ServletContext attributes that exist before the startup of the Spring application context. Typically, such attributes will have been put there by third-party web frameworks. In a purely Spring-based web application, no such linking in of ServletContext attrutes will be necessary.

Since:

1.1.4

Author:

Juergen Hoeller

See Also:

ServletContextParameterFactoryBean

Constructor Summary

ServletContextAttributeFactoryBean()

Method Summary

Object	getObject() Return an instance (possibly shared or independent) of the object managed by this factory.
Class	getObjectType() Return the type of object that this FactoryBean creates, or null if not known in advance.
boolean	isSingleton() Is the bean managed by this factory a singleton or a prototype?
void	setAttributeName(String attributeName) Set the name of the ServletContext attribute to expose.
void	setServletContext(ServletContext servletContext) Set the ServletContext that this object runs in.

Methods inherited from class java.lang.Object

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

Constructor Detail

ServletContextAttributeFactoryBean

public ServletContextAttributeFactoryBean()

Method Detail

setAttributeName

public void setAttributeName(String attributeName)

Set the name of the ServletContext attribute to expose.

setServletContext

public void setServletContext(ServletContext servletContext)

Description copied from interface: ServletContextAware

Set the ServletContext that this object runs in.

Invoked after population of normal bean properties but before an init callback like InitializingBean's afterPropertiesSet or a custom init-method. Invoked after ApplicationContextAware's setApplicationContext.

Specified by:

setServletContext in interface ServletContextAware

Parameters:

servletContext - ServletContext object to be used by this object

getObject

public Object getObject()
                 throws Exception

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 method returns null, the factory will consider the FactoryBean as not fully initialized and throw a corresponding FactoryBeanNotInitializedException.

Specified by:

getObject in interface FactoryBean

Returns:

an instance of the bean (should not be null; a null value will be considered as an indication of incomplete initialization)

Throws:

Exception - in case of creation errors

See Also:

FactoryBeanNotInitializedException

getObjectType

public 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 to check for specific types of beans without instantiating objects, for example on autowiring.

For a singleton, this 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

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)

isSingleton

public boolean isSingleton()

Description copied from interface: FactoryBean

Is the bean managed by this factory a singleton or a prototype? That is, will 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.

Specified by:

isSingleton in interface FactoryBean

Returns:

if this bean is a singleton

See Also:

FactoryBean.getObject()