Class ApplicationObjectSupport

java.lang.Object

org.springframework.context.support.ApplicationObjectSupport

All Implemented Interfaces:

Aware, ApplicationContextAware

Direct Known Subclasses:

AbstractHandlerMapping, WebApplicationObjectSupport

public abstract class ApplicationObjectSupport
extends Object
implements ApplicationContextAware

Convenient superclass for application objects that want to be aware of the application context, for example, for custom lookup of collaborating beans or for context-specific resource access. It saves the application context reference and provides an initialization callback method. Furthermore, it offers numerous convenience methods for message lookup.

There is no requirement to subclass this class: It just makes things a little easier if you need access to the context, for example, for access to file resources or to the message source. Note that many application objects do not need to be aware of the application context at all, as they can receive collaborating beans via bean references.

Many framework classes are derived from this class, particularly within the web support.

Author:

Rod Johnson, Juergen Hoeller

See Also:

• WebApplicationObjectSupport

Field Summary

Fields

Modifier and Type	Field	Description
protected final org.apache.commons.logging.Log	logger	Logger that is available to subclasses.

Constructor Summary

Constructors

Constructor	Description
ApplicationObjectSupport()

Method Summary

Modifier and Type	Method	Description
final @Nullable ApplicationContext	getApplicationContext()	Return the ApplicationContext that this object is associated with.
protected final @Nullable MessageSourceAccessor	getMessageSourceAccessor()	Return a MessageSourceAccessor for the application context used by this object, for easy message access.
protected void	initApplicationContext()	Subclasses can override this for custom initialization behavior.
protected void	initApplicationContext(ApplicationContext context)	Subclasses can override this for custom initialization behavior.
protected boolean	isContextRequired()	Determine whether this application object needs to run in an ApplicationContext.
protected final ApplicationContext	obtainApplicationContext()	Obtain the ApplicationContext for actual use.
protected Class<?>	requiredContextClass()	Determine the context class that any context passed to setApplicationContext must be an instance of.
final void	setApplicationContext(@Nullable ApplicationContext context)	Set the ApplicationContext that this object runs in.

Methods inherited from class Object

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

Field Details

logger

protected final org.apache.commons.logging.Log logger

Logger that is available to subclasses.

Constructor Details

ApplicationObjectSupport

public ApplicationObjectSupport()

Method Details

setApplicationContext

public final void setApplicationContext(@Nullable ApplicationContext context)
                                 throws BeansException

Description copied from interface: ApplicationContextAware

Set the ApplicationContext that this object runs in. Normally this call will be used to initialize the object.

Invoked after population of normal bean properties but before an init callback such as InitializingBean.afterPropertiesSet() or a custom init-method. Invoked after ResourceLoaderAware.setResourceLoader(ResourceLoader), ApplicationEventPublisherAware.setApplicationEventPublisher(ApplicationEventPublisher) and MessageSourceAware, if applicable.

Specified by:

setApplicationContext in interface ApplicationContextAware

Parameters:

context - the ApplicationContext object to be used by this object

Throws:

BeansException - if thrown by application context methods

See Also:

• BeanInitializationException

isContextRequired

protected boolean isContextRequired()

Determine whether this application object needs to run in an ApplicationContext.

Default is "false". Can be overridden to enforce running in a context (i.e. to throw IllegalStateException on accessors if outside a context).

See Also:

• getApplicationContext()
• getMessageSourceAccessor()

requiredContextClass

protected Class<?> requiredContextClass()

Determine the context class that any context passed to setApplicationContext must be an instance of. Can be overridden in subclasses.

See Also:

• setApplicationContext(ApplicationContext)

initApplicationContext

protected void initApplicationContext(ApplicationContext context)
                               throws BeansException

Subclasses can override this for custom initialization behavior. Gets called by setApplicationContext after setting the context instance.

Note: Does not get called on re-initialization of the context but rather just on first initialization of this object's context reference.

The default implementation calls the overloaded initApplicationContext() method without ApplicationContext reference.

Parameters:

context - the containing ApplicationContext

Throws:

ApplicationContextException - in case of initialization errors

BeansException - if thrown by ApplicationContext methods

See Also:

• setApplicationContext(ApplicationContext)

initApplicationContext

protected void initApplicationContext()
                               throws BeansException

Subclasses can override this for custom initialization behavior.

The default implementation is empty. Called by initApplicationContext(ApplicationContext).

Throws:

ApplicationContextException - in case of initialization errors

BeansException - if thrown by ApplicationContext methods

See Also:

• setApplicationContext(ApplicationContext)

getApplicationContext

public final @Nullable ApplicationContext getApplicationContext()
                                                         throws IllegalStateException

Return the ApplicationContext that this object is associated with.

Throws:

IllegalStateException - if not running in an ApplicationContext

obtainApplicationContext

protected final ApplicationContext obtainApplicationContext()

Obtain the ApplicationContext for actual use.

Returns:

the ApplicationContext (never null)

Throws:

IllegalStateException - in case of no ApplicationContext set

Since:

5.0

getMessageSourceAccessor

protected final @Nullable MessageSourceAccessor getMessageSourceAccessor()
                                                                  throws IllegalStateException

Return a MessageSourceAccessor for the application context used by this object, for easy message access.

Throws:

IllegalStateException - if not running in an ApplicationContext