org.springframework.context.support
Class ApplicationObjectSupport

java.lang.Object
  org.springframework.context.support.ApplicationObjectSupport

All Implemented Interfaces:

ApplicationContextAware

Direct Known Subclasses:

WebApplicationObjectSupport

public abstract class ApplicationObjectSupport
extends Object
implements ApplicationContextAware

Convenient superclass for application objects that want to be aware of the application context, e.g. 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, e.g. 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

protected org.apache.commons.logging.Log

logger Logger that is available to subclasses

Constructor Summary

ApplicationObjectSupport()

Method Summary

ApplicationContext	getApplicationContext() Return the ApplicationContext instance used by this object.
protected 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 boolean	isContextRequired() Determine whether this application object needs to run in an ApplicationContext.
protected Class	requiredContextClass() Determine the context class that any context passed to setApplicationContext must be an instance of.
void	setApplicationContext(ApplicationContext context) Set the ApplicationContext that this object runs in.

Methods inherited from class java.lang.Object

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

Field Detail

logger

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

Logger that is available to subclasses

Constructor Detail

ApplicationObjectSupport

public ApplicationObjectSupport()

Method Detail

setApplicationContext

public final void setApplicationContext(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 like InitializingBean's afterPropertiesSet or a custom init-method. Invoked after ResourceLoaderAware's setResourceLoader.

Specified by:

setApplicationContext in interface ApplicationContextAware

Parameters:

context - ApplicationContext object to be used by this object

Throws:

ApplicationContextException - in case of applicationContext initialization errors

BeansException - if thrown by application applicationContext 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(org.springframework.context.ApplicationContext)

initApplicationContext

protected void initApplicationContext()
                               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 reinitialization of the context but rather just on first initialization of this object's context reference.

Throws:

ApplicationContextException - in case of initialization errors

BeansException - if thrown by ApplicationContext methods

See Also:

setApplicationContext(org.springframework.context.ApplicationContext)

getApplicationContext

public final ApplicationContext getApplicationContext()
                                               throws IllegalStateException

Return the ApplicationContext instance used by this object.

Throws:

IllegalStateException

getMessageSourceAccessor

protected final 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