Top Description Fields Constructors Methods
org.springframework.web.context.support

public Class ServletContextAttributeFactoryBean

extends Object
implements FactoryBean<Object>, ServletContextAware
Class Inheritance
All Implemented Interfaces
org.springframework.web.context.ServletContextAware, org.springframework.beans.factory.Aware, org.springframework.beans.factory.FactoryBean
Imports
jakarta.servlet.ServletContext, org.springframework.beans.factory.FactoryBean, org.springframework.lang.Nullable, org.springframework.web.context.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 attributes will be necessary.

Note

You may also use the "contextAttributes" default bean, which is of type Map, and dereference it using a "#{contextAttributes.myKey}" expression to access a specific attribute by name.

Author
Juergen Hoeller
Since
1.1.4
See Also
org.springframework.web.context.WebApplicationContext#CONTEXT_ATTRIBUTES_BEAN_NAME, ServletContextParameterFactoryBean

Field Summary

Modifier and TypeField and Description
private Object
private String

Constructor Summary

AccessConstructor and Description
public

Method Summary

Modifier and TypeMethod and Description
public Object
getObject()

Implements org.springframework.beans.factory.FactoryBean.getObject.

Return an instance (possibly shared or independent) of the object managed by this factory.
public Class<?>
getObjectType()

Implements org.springframework.beans.factory.FactoryBean.getObjectType.

Return the type of object that this FactoryBean creates, or null if not known in advance.
public boolean
isSingleton()

Overrides default org.springframework.beans.factory.FactoryBean.isSingleton.

Is the object managed by this factory a singleton?
public void
setAttributeName(String attributeName)

Set the name of the ServletContext attribute to expose.

public void
setServletContext(ServletContext
the ServletContext object to be used by this object
servletContext
)

Implements org.springframework.web.context.ServletContextAware.setServletContext.

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.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

attributeback to summary
private Object attribute
Annotations
@Nullable
attributeNameback to summary
private String attributeName
Annotations
@Nullable

Constructor Detail

ServletContextAttributeFactoryBeanback to summary
public ServletContextAttributeFactoryBean()

Method Detail

getObjectback to summary
public Object getObject() throws Exception

Implements org.springframework.beans.factory.FactoryBean.getObject.

Doc from org.springframework.beans.factory.FactoryBean.getObject.

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.

Returns:Object

an instance of the bean (can be null)

Annotations
@Override
@Nullable
Exceptions
Exception:
in case of creation errors
getObjectTypeback to summary
public Class<?> getObjectType()

Implements org.springframework.beans.factory.FactoryBean.getObjectType.

Doc from org.springframework.beans.factory.FactoryBean.getObjectType.

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.

Returns:Class<?>

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

Annotations
@Override
isSingletonback to summary
public boolean isSingleton()

Overrides default org.springframework.beans.factory.FactoryBean.isSingleton.

Doc from org.springframework.beans.factory.FactoryBean.isSingleton.

Is the object managed by this factory a singleton? 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.

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.

The default implementation returns true, since a FactoryBean typically manages a singleton instance.

Returns:boolean

whether the exposed object is a singleton

Annotations
@Override
setAttributeNameback to summary
public void setAttributeName(String attributeName)

Set the name of the ServletContext attribute to expose.

setServletContextback to summary
public void setServletContext(ServletContext servletContext)

Implements org.springframework.web.context.ServletContextAware.setServletContext.

Doc from org.springframework.web.context.ServletContextAware.setServletContext.

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.

Parameters
servletContext:ServletContext

the ServletContext object to be used by this object

Annotations
@Override