Spring Framework

org.springframework.context.annotation
Class CommonAnnotationBeanPostProcessor

java.lang.Object
  extended by org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor
      extended by org.springframework.context.annotation.CommonAnnotationBeanPostProcessor
All Implemented Interfaces:
java.io.Serializable, Aware, BeanFactoryAware, BeanPostProcessor, DestructionAwareBeanPostProcessor, InstantiationAwareBeanPostProcessor, MergedBeanDefinitionPostProcessor, Ordered, PriorityOrdered

public class CommonAnnotationBeanPostProcessor
extends InitDestroyAnnotationBeanPostProcessor
implements InstantiationAwareBeanPostProcessor, BeanFactoryAware, java.io.Serializable

BeanPostProcessor implementation that supports common Java annotations out of the box, in particular the JSR-250 annotations in the javax.annotation package. These common Java annotations are supported in many Java EE 5 technologies (e.g. JSF 1.2), as well as in Java 6's JAX-WS.

This post-processor includes support for the PostConstruct and PreDestroy annotations - as init annotation and destroy annotation, respectively - through inheriting from InitDestroyAnnotationBeanPostProcessor with pre-configured annotation types.

The central element is the Resource annotation for annotation-driven injection of named beans, by default from the containing Spring BeanFactory, with only mappedName references resolved in JNDI. The "alwaysUseJndiLookup" flag enforces JNDI lookups equivalent to standard Java EE 5 resource injection for name references and default names as well. The target beans can be simple POJOs, with no special requirements other than the type having to match.

The JAX-WS WebServiceRef annotation is supported too, analogous to Resource but with the capability of creating specific JAX-WS service endpoints. This may either point to an explicitly defined resource by name or operate on a locally specified JAX-WS service class. Finally, this post-processor also supports the EJB 3 EJB annotation, analogous to Resource as well, with the capability to specify both a local bean name and a global JNDI name for fallback retrieval. The target beans can be plain POJOs as well as EJB 3 Session Beans in this case.

The common annotations supported by this post-processor are available in Java 6 (JDK 1.6) as well as in Java EE 5/6 (which provides a standalone jar for its common annotations as well, allowing for use in any Java 5 based application). Hence, this post-processor works out of the box on JDK 1.6, and requires the JSR-250 API jar (and optionally the JAX-WS API jar and/or the EJB 3 API jar) to be added to the classpath on JDK 1.5 (when running outside of Java EE 5/6).

For default usage, resolving resource names as Spring bean names, simply define the following in your application context:

 <bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor"/>
For direct JNDI access, resolving resource names as JNDI resource references within the Java EE application's "java:comp/env/" namespace, use the following:
 <bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor">
   <property name="alwaysUseJndiLookup" value="true"/>
 </bean>
mappedName references will always be resolved in JNDI, allowing for global JNDI names (including "java:" prefix) as well. The "alwaysUseJndiLookup" flag just affects name references and default names (inferred from the field name / property name).

NOTE: A default CommonAnnotationBeanPostProcessor will be registered by the "context:annotation-config" and "context:component-scan" XML tags. Remove or turn off the default annotation configuration there if you intend to specify a custom CommonAnnotationBeanPostProcessor bean definition!

NOTE: Annotation injection will be performed before XML injection; thus the latter configuration will override the former for properties wired through both approaches.

Since:
2.5
Author:
Juergen Hoeller
See Also:
setAlwaysUseJndiLookup(boolean), setResourceFactory(org.springframework.beans.factory.BeanFactory), InitDestroyAnnotationBeanPostProcessor, AutowiredAnnotationBeanPostProcessor, Serialized Form

Nested Class Summary
protected  class CommonAnnotationBeanPostProcessor.LookupElement
          Class representing generic injection information about an annotated field or setter method, supporting @Resource and related annotations.
 
Field Summary
 
Fields inherited from class org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor
logger
 
Fields inherited from interface org.springframework.core.Ordered
HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE
 
Constructor Summary
CommonAnnotationBeanPostProcessor()
          Create a new CommonAnnotationBeanPostProcessor, with the init and destroy annotation types set to PostConstruct and PreDestroy, respectively.
 
Method Summary
protected  java.lang.Object autowireResource(BeanFactory factory, CommonAnnotationBeanPostProcessor.LookupElement element, java.lang.String requestingBeanName)
          Obtain a resource object for the given name and type through autowiring based on the given factory.
protected  java.lang.Object getResource(CommonAnnotationBeanPostProcessor.LookupElement element, java.lang.String requestingBeanName)
          Obtain the resource object for the given name and type.
 void ignoreResourceType(java.lang.String resourceType)
          Ignore the given resource type when resolving @Resource annotations.
 boolean postProcessAfterInstantiation(java.lang.Object bean, java.lang.String beanName)
          Perform operations after the bean has been instantiated, via a constructor or factory method, but before Spring property population (from explicit properties or autowiring) occurs.
 java.lang.Object postProcessBeforeInstantiation(java.lang.Class<?> beanClass, java.lang.String beanName)
          Apply this BeanPostProcessor before the target bean gets instantiated.
 void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, java.lang.Class<?> beanType, java.lang.String beanName)
          Post-process the given merged bean definition for the specified bean.
 PropertyValues postProcessPropertyValues(PropertyValues pvs, java.beans.PropertyDescriptor[] pds, java.lang.Object bean, java.lang.String beanName)
          Post-process the given property values before the factory applies them to the given bean.
 void setAlwaysUseJndiLookup(boolean alwaysUseJndiLookup)
          Set whether to always use JNDI lookups equivalent to standard Java EE 5 resource injection, even for name attributes and default names.
 void setBeanFactory(BeanFactory beanFactory)
          Callback that supplies the owning factory to a bean instance.
 void setFallbackToDefaultTypeMatch(boolean fallbackToDefaultTypeMatch)
          Set whether to allow a fallback to a type match if no explicit name has been specified.
 void setJndiFactory(BeanFactory jndiFactory)
          Specify the factory for objects to be injected into @Resource / @WebServiceRef / @EJB annotated fields and setter methods, for mappedName attributes that point directly into JNDI.
 void setResourceFactory(BeanFactory resourceFactory)
          Specify the factory for objects to be injected into @Resource / @WebServiceRef / @EJB annotated fields and setter methods, for name attributes and default names.
 
Methods inherited from class org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor
getOrder, postProcessAfterInitialization, postProcessBeforeDestruction, postProcessBeforeInitialization, setDestroyAnnotationType, setInitAnnotationType, setOrder
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.springframework.beans.factory.config.BeanPostProcessor
postProcessAfterInitialization, postProcessBeforeInitialization
 

Constructor Detail

CommonAnnotationBeanPostProcessor

public CommonAnnotationBeanPostProcessor()
Create a new CommonAnnotationBeanPostProcessor, with the init and destroy annotation types set to PostConstruct and PreDestroy, respectively.

Method Detail

ignoreResourceType

public void ignoreResourceType(java.lang.String resourceType)
Ignore the given resource type when resolving @Resource annotations.

By default, the javax.xml.ws.WebServiceContext interface will be ignored, since it will be resolved by the JAX-WS runtime.

Parameters:
resourceType - the resource type to ignore

setFallbackToDefaultTypeMatch

public void setFallbackToDefaultTypeMatch(boolean fallbackToDefaultTypeMatch)
Set whether to allow a fallback to a type match if no explicit name has been specified. The default name (i.e. the field name or bean property name) will still be checked first; if a bean of that name exists, it will be taken. However, if no bean of that name exists, a by-type resolution of the dependency will be attempted if this flag is "true".

Default is "true". Switch this flag to "false" in order to enforce a by-name lookup in all cases, throwing an exception in case of no name match.

See Also:
AutowireCapableBeanFactory.resolveDependency(org.springframework.beans.factory.config.DependencyDescriptor, java.lang.String)

setAlwaysUseJndiLookup

public void setAlwaysUseJndiLookup(boolean alwaysUseJndiLookup)
Set whether to always use JNDI lookups equivalent to standard Java EE 5 resource injection, even for name attributes and default names.

Default is "false": Resource names are used for Spring bean lookups in the containing BeanFactory; only mappedName attributes point directly into JNDI. Switch this flag to "true" for enforcing Java EE style JNDI lookups in any case, even for name attributes and default names.

See Also:
setJndiFactory(org.springframework.beans.factory.BeanFactory), setResourceFactory(org.springframework.beans.factory.BeanFactory)

setJndiFactory

public void setJndiFactory(BeanFactory jndiFactory)
Specify the factory for objects to be injected into @Resource / @WebServiceRef / @EJB annotated fields and setter methods, for mappedName attributes that point directly into JNDI. This factory will also be used if "alwaysUseJndiLookup" is set to "true" in order to enforce JNDI lookups even for name attributes and default names.

The default is a SimpleJndiBeanFactory for JNDI lookup behavior equivalent to standard Java EE 5 resource injection.

See Also:
setResourceFactory(org.springframework.beans.factory.BeanFactory), setAlwaysUseJndiLookup(boolean)

setResourceFactory

public void setResourceFactory(BeanFactory resourceFactory)
Specify the factory for objects to be injected into @Resource / @WebServiceRef / @EJB annotated fields and setter methods, for name attributes and default names.

The default is the BeanFactory that this post-processor is defined in, if any, looking up resource names as Spring bean names. Specify the resource factory explicitly for programmatic usage of this post-processor.

Specifying Spring's SimpleJndiBeanFactory leads to JNDI lookup behavior equivalent to standard Java EE 5 resource injection, even for name attributes and default names. This is the same behavior that the "alwaysUseJndiLookup" flag enables.

See Also:
setAlwaysUseJndiLookup(boolean)

setBeanFactory

public void setBeanFactory(BeanFactory beanFactory)
                    throws BeansException
Description copied from interface: BeanFactoryAware
Callback that supplies the owning factory to a bean instance.

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

Specified by:
setBeanFactory in interface BeanFactoryAware
Parameters:
beanFactory - owning BeanFactory (never null). The bean can immediately call methods on the factory.
Throws:
BeansException - in case of initialization errors
See Also:
BeanInitializationException

postProcessMergedBeanDefinition

public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition,
                                            java.lang.Class<?> beanType,
                                            java.lang.String beanName)
Description copied from interface: MergedBeanDefinitionPostProcessor
Post-process the given merged bean definition for the specified bean.

Specified by:
postProcessMergedBeanDefinition in interface MergedBeanDefinitionPostProcessor
Overrides:
postProcessMergedBeanDefinition in class InitDestroyAnnotationBeanPostProcessor
Parameters:
beanDefinition - the merged bean definition for the bean
beanType - the actual type of the managed bean instance
beanName - the name of the bean

postProcessBeforeInstantiation

public java.lang.Object postProcessBeforeInstantiation(java.lang.Class<?> beanClass,
                                                       java.lang.String beanName)
                                                throws BeansException
Description copied from interface: InstantiationAwareBeanPostProcessor
Apply this BeanPostProcessor before the target bean gets instantiated. The returned bean object may be a proxy to use instead of the target bean, effectively suppressing default instantiation of the target bean.

If a non-null object is returned by this method, the bean creation process will be short-circuited. The only further processing applied is the BeanPostProcessor.postProcessAfterInitialization(java.lang.Object, java.lang.String) callback from the configured BeanPostProcessors.

This callback will only be applied to bean definitions with a bean class. In particular, it will not be applied to beans with a "factory-method".

Post-processors may implement the extended SmartInstantiationAwareBeanPostProcessor interface in order to predict the type of the bean object that they are going to return here.

Specified by:
postProcessBeforeInstantiation in interface InstantiationAwareBeanPostProcessor
Parameters:
beanClass - the class of the bean to be instantiated
beanName - the name of the bean
Returns:
the bean object to expose instead of a default instance of the target bean, or null to proceed with default instantiation
Throws:
BeansException - in case of errors
See Also:
AbstractBeanDefinition.hasBeanClass(), AbstractBeanDefinition.getFactoryMethodName()

postProcessAfterInstantiation

public boolean postProcessAfterInstantiation(java.lang.Object bean,
                                             java.lang.String beanName)
                                      throws BeansException
Description copied from interface: InstantiationAwareBeanPostProcessor
Perform operations after the bean has been instantiated, via a constructor or factory method, but before Spring property population (from explicit properties or autowiring) occurs.

This is the ideal callback for performing field injection on the given bean instance. See Spring's own AutowiredAnnotationBeanPostProcessor for a typical example.

Specified by:
postProcessAfterInstantiation in interface InstantiationAwareBeanPostProcessor
Parameters:
bean - the bean instance created, with properties not having been set yet
beanName - the name of the bean
Returns:
true if properties should be set on the bean; false if property population should be skipped. Normal implementations should return true. Returning false will also prevent any subsequent InstantiationAwareBeanPostProcessor instances being invoked on this bean instance.
Throws:
BeansException - in case of errors

postProcessPropertyValues

public PropertyValues postProcessPropertyValues(PropertyValues pvs,
                                                java.beans.PropertyDescriptor[] pds,
                                                java.lang.Object bean,
                                                java.lang.String beanName)
                                         throws BeansException
Description copied from interface: InstantiationAwareBeanPostProcessor
Post-process the given property values before the factory applies them to the given bean. Allows for checking whether all dependencies have been satisfied, for example based on a "Required" annotation on bean property setters.

Also allows for replacing the property values to apply, typically through creating a new MutablePropertyValues instance based on the original PropertyValues, adding or removing specific values.

Specified by:
postProcessPropertyValues in interface InstantiationAwareBeanPostProcessor
Parameters:
pvs - the property values that the factory is about to apply (never null)
pds - the relevant property descriptors for the target bean (with ignored dependency types - which the factory handles specifically - already filtered out)
bean - the bean instance created, but whose properties have not yet been set
beanName - the name of the bean
Returns:
the actual property values to apply to to the given bean (can be the passed-in PropertyValues instance), or null to skip property population
Throws:
BeansException - in case of errors
See Also:
MutablePropertyValues

getResource

protected java.lang.Object getResource(CommonAnnotationBeanPostProcessor.LookupElement element,
                                       java.lang.String requestingBeanName)
                                throws BeansException
Obtain the resource object for the given name and type.

Parameters:
element - the descriptor for the annotated field/method
requestingBeanName - the name of the requesting bean
Returns:
the resource object (never null)
Throws:
BeansException - if we failed to obtain the target resource

autowireResource

protected java.lang.Object autowireResource(BeanFactory factory,
                                            CommonAnnotationBeanPostProcessor.LookupElement element,
                                            java.lang.String requestingBeanName)
                                     throws BeansException
Obtain a resource object for the given name and type through autowiring based on the given factory.

Parameters:
factory - the factory to autowire against
element - the descriptor for the annotated field/method
requestingBeanName - the name of the requesting bean
Returns:
the resource object (never null)
Throws:
BeansException - if we failed to obtain the target resource

Spring Framework