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PersistenceAnnotationBeanPostProcessor (Spring Framework API 2.0) - Spring Framework 2.0.5 API 文档英文版

The Spring Framework

org.springframework.orm.jpa.support
Class PersistenceAnnotationBeanPostProcessor

java.lang.Object
  extended by org.springframework.jndi.JndiAccessor
      extended by org.springframework.jndi.JndiLocatorSupport
          extended by org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor
All Implemented Interfaces:
BeanFactoryAware, BeanPostProcessor, InstantiationAwareBeanPostProcessor

public class PersistenceAnnotationBeanPostProcessor
extends JndiLocatorSupport
implements InstantiationAwareBeanPostProcessor, BeanFactoryAware

BeanPostProcessor that processes PersistenceUnit and PersistenceContext annotations, for injection of the corresponding JPA resources EntityManagerFactory and EntityManager. Any such annotated fields or methods in any Spring-managed object will automatically be injected.

This post-processor will inject sub-interfaces of EntityManagerFactory and EntityManager if the annotated fields or methods are declared as such. The actual type will be verified early, with the exception of a shared ("transactional") EntityManager reference, where type mismatches might be detected as late as on the first actual invocation.

Note: In the present implementation, PersistenceAnnotationBeanPostProcessor only supports @PersistenceUnit and @PersistenceContext with the "unitName" attribute, or no attribute at all (for the default unit). If those annotations are present with the "name" attribute at the class level, they will simply be ignored, since those only serve as deployment hint (as per the Java EE 5 specification).

This post-processor can either obtain EntityManagerFactory beans defined in the Spring application context (the default), or obtain EntityManagerFactory references from JNDI ("persistence unit references"). In the bean case, the persistence unit name will be matched against the actual deployed unit, with the bean name used as fallback unit name if no deployed name found. Typically, Spring's LocalContainerEntityManagerFactoryBean will be used for setting up such EntityManagerFactory beans. The post-processor definition will then look as simple as this:

 <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
In the JNDI case, specify the corresponding JNDI names in this post-processor's "persistenceUnits" map, typically with matching persistence-unit-ref entries in the Java EE deployment descriptor. By default, those names are considered as resource references (according to the Java EE resource-ref convention), located underneath the "java:comp/env/" namespace. For example:
 <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor">
   <property name="persistenceUnits">
     <map/gt;
       <entry key="unit1" value="persistence/unit1"/>
       <entry key="unit2" value="persistence/unit2"/>
     </map/gt;
   </property>
 </bean>
In this case, the specified persistence units will always be resolved in JNDI rather than as Spring-defined beans. The entire persistence unit deployment, including the weaving of persistent classes, is then up to the Java EE server. Persistence contexts (i.e. EntityManager references) will be built based on those server-provided EntityManagerFactory references, using Spring's own transaction synchronization facilities for transactional EntityManager handling (typically with Spring's @Transactional annotation for demarcation and JtaTransactionManager as backend).

If you prefer the Java EE server's own EntityManager handling, specify entries in this post-processor's "persistenceContexts" map (or "extendedPersistenceContexts" map, typically with matching persistence-context-ref entries in the Java EE deployment descriptor. For example:

 <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor">
   <property name="persistenceContexts">
     <map/gt;
       <entry key="unit1" value="persistence/context1"/>
       <entry key="unit2" value="persistence/context2"/>
     </map/gt;
   </property>
 </bean>
If the application only obtains EntityManager references in the first place, this is all you need to specify. If you need EntityManagerFactory references as well, specify entries for both "persistenceUnits" and "persistenceContexts", pointing to matching JNDI locations.

NOTE: In general, do not inject EXTENDED EntityManagers into STATELESS beans, i.e. do not use @PersistenceContext with type EXTENDED in Spring beans defined with scope 'singleton' (Spring's default scope). Extended EntityManagers are not thread-safe, hence they must not be used in concurrently accessed beans (which Spring-managed singletons usually are).

Since:
2.0
Author:
Rod Johnson, Juergen Hoeller
See Also:
PersistenceUnit, PersistenceContext

Field Summary
 
Fields inherited from class org.springframework.jndi.JndiLocatorSupport
CONTAINER_PREFIX
 
Fields inherited from class org.springframework.jndi.JndiAccessor
logger
 
Constructor Summary
PersistenceAnnotationBeanPostProcessor()
           
 
Method Summary
protected  javax.persistence.EntityManagerFactory findDefaultEntityManagerFactory()
          Find a single default EntityManagerFactory in the Spring application context.
protected  javax.persistence.EntityManagerFactory findEntityManagerFactory(String unitName)
          Find an EntityManagerFactory with the given name in the current Spring application context, falling back to a single default EntityManagerFactory (if any) in case of no unit name specified.
protected  javax.persistence.EntityManagerFactory findNamedEntityManagerFactory(String unitName)
          Find an EntityManagerFactory with the given name in the current Spring application context.
protected  javax.persistence.EntityManager getPersistenceContext(String unitName, boolean extended)
          Return a specified persistence context for the given unit name, as defined through the "persistenceContexts" (or "extendedPersistenceContexts") map.
protected  javax.persistence.EntityManagerFactory getPersistenceUnit(String unitName)
          Return a specified persistence unit for the given unit name, as defined through the "persistenceUnits" map.
 Object postProcessAfterInitialization(Object bean, String beanName)
          Apply this BeanPostProcessor to the given new bean instance after any bean initialization callbacks (like InitializingBean's afterPropertiesSet or a custom init-method).
 boolean postProcessAfterInstantiation(Object bean, 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.
 Object postProcessBeforeInitialization(Object bean, String beanName)
          Apply this BeanPostProcessor to the given new bean instance before any bean initialization callbacks (like InitializingBean's afterPropertiesSet or a custom init-method).
 Object postProcessBeforeInstantiation(Class beanClass, String beanName)
          Apply this BeanPostProcessor before the target bean gets instantiated.
 PropertyValues postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName)
          Post-process the given property values before the factory applies them to the given bean.
 void setBeanFactory(BeanFactory beanFactory)
          Callback that supplies the owning factory to a bean instance.
 void setDefaultPersistenceUnitName(String unitName)
          Specify the default persistence unit name, to be used in case of no unit name specified in an @PersistenceUnit / @PersistenceContext annotation.
 void setExtendedPersistenceContexts(Map<String,String> extendedPersistenceContexts)
          Specify the extended persistence contexts for EntityManager lookups, as a Map from persistence unit name to persistence context JNDI name (which needs to resolve to an EntityManager instance).
 void setPersistenceContexts(Map<String,String> persistenceContexts)
          Specify the transactional persistence contexts for EntityManager lookups, as a Map from persistence unit name to persistence context JNDI name (which needs to resolve to an EntityManager instance).
 void setPersistenceUnits(Map<String,String> persistenceUnits)
          Specify the persistence units for EntityManagerFactory lookups, as a Map from persistence unit name to persistence unit JNDI name (which needs to resolve to an EntityManagerFactory instance).
 
Methods inherited from class org.springframework.jndi.JndiLocatorSupport
convertJndiName, isResourceRef, lookup, lookup, setResourceRef
 
Methods inherited from class org.springframework.jndi.JndiAccessor
getJndiEnvironment, getJndiTemplate, setJndiEnvironment, setJndiTemplate
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

PersistenceAnnotationBeanPostProcessor

public PersistenceAnnotationBeanPostProcessor()
Method Detail

setPersistenceUnits

public void setPersistenceUnits(Map<String,String> persistenceUnits)
Specify the persistence units for EntityManagerFactory lookups, as a Map from persistence unit name to persistence unit JNDI name (which needs to resolve to an EntityManagerFactory instance).

JNDI names specified here should refer to persistence-unit-ref entries in the Java EE deployment descriptor, matching the target persistence unit.

In case of no unit name specified in the annotation, the specified value for the default persistence unit will be taken (by default, the value mapped to the empty String), or simply the single persistence unit if there is only one.

This is mainly intended for use in a Java EE 5 environment, with all lookup driven by the standard JPA annotations, and all EntityManagerFactory references obtained from JNDI. No separate EntityManagerFactory bean definitions are necessary in such a scenario.

If no corresponding "persistenceContexts"/"extendedPersistenceContexts" are specified, @PersistenceContext will be resolved to EntityManagers built on top of the EntityManagerFactory defined here. Note that those will be Spring-managed EntityManagers, which implement transaction synchronization based on Spring's facilities. If you prefer the Java EE 5 server's own EntityManager handling, specify corresponding "persistenceContexts"/"extendedPersistenceContexts".


setPersistenceContexts

public void setPersistenceContexts(Map<String,String> persistenceContexts)
Specify the transactional persistence contexts for EntityManager lookups, as a Map from persistence unit name to persistence context JNDI name (which needs to resolve to an EntityManager instance).

JNDI names specified here should refer to persistence-context-ref entries in the Java EE deployment descriptors, matching the target persistence unit and being set up with persistence context type Transaction.

In case of no unit name specified in the annotation, the specified value for the default persistence unit will be taken (by default, the value mapped to the empty String), or simply the single persistence unit if there is only one.

This is mainly intended for use in a Java EE 5 environment, with all lookup driven by the standard JPA annotations, and all EntityManager references obtained from JNDI. No separate EntityManagerFactory bean definitions are necessary in such a scenario, and all EntityManager handling is done by the Java EE 5 server itself.


setExtendedPersistenceContexts

public void setExtendedPersistenceContexts(Map<String,String> extendedPersistenceContexts)
Specify the extended persistence contexts for EntityManager lookups, as a Map from persistence unit name to persistence context JNDI name (which needs to resolve to an EntityManager instance).

JNDI names specified here should refer to persistence-context-ref entries in the Java EE deployment descriptors, matching the target persistence unit and being set up with persistence context type Extended.

In case of no unit name specified in the annotation, the specified value for the default persistence unit will be taken (by default, the value mapped to the empty String), or simply the single persistence unit if there is only one.

This is mainly intended for use in a Java EE 5 environment, with all lookup driven by the standard JPA annotations, and all EntityManager references obtained from JNDI. No separate EntityManagerFactory bean definitions are necessary in such a scenario, and all EntityManager handling is done by the Java EE 5 server itself.


setDefaultPersistenceUnitName

public void setDefaultPersistenceUnitName(String unitName)
Specify the default persistence unit name, to be used in case of no unit name specified in an @PersistenceUnit / @PersistenceContext annotation.

This is mainly intended for lookups in the application context, indicating the target persistence unit name (typically matching the bean name), but also applies to lookups in the "persistenceUnits" / "persistenceContexts" / "extendedPersistenceContexts" map, avoiding the need for duplicated mappings for the empty String there.

Default is to check for a single EntityManagerFactory bean in the Spring application context, if any. If there are multiple such factories, either specify this default persistence unit name or explicitly refer to named persistence units in your annotations.


setBeanFactory

public void setBeanFactory(BeanFactory beanFactory)
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.
See Also:
BeanInitializationException

postProcessBeforeInstantiation

public Object postProcessBeforeInstantiation(Class beanClass,
                                             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(Object bean,
                                             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.

Specified by:
postProcessAfterInstantiation in interface InstantiationAwareBeanPostProcessor
Parameters:
bean - the bean instance created, but whose properties have not yet been set
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,
                                                PropertyDescriptor[] pds,
                                                Object bean,
                                                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

postProcessBeforeInitialization

public Object postProcessBeforeInitialization(Object bean,
                                              String beanName)
                                       throws BeansException
Description copied from interface: BeanPostProcessor
Apply this BeanPostProcessor to the given new bean instance before any bean initialization callbacks (like InitializingBean's afterPropertiesSet or a custom init-method). The bean will already be populated with property values. The returned bean instance may be a wrapper around the original.

Specified by:
postProcessBeforeInitialization in interface BeanPostProcessor
Parameters:
bean - the new bean instance
beanName - the name of the bean
Returns:
the bean instance to use, either the original or a wrapped one
Throws:
BeansException - in case of errors
See Also:
InitializingBean.afterPropertiesSet()

postProcessAfterInitialization

public Object postProcessAfterInitialization(Object bean,
                                             String beanName)
                                      throws BeansException
Description copied from interface: BeanPostProcessor
Apply this BeanPostProcessor to the given new bean instance after any bean initialization callbacks (like InitializingBean's afterPropertiesSet or a custom init-method). The bean will already be populated with property values. The returned bean instance may be a wrapper around the original.

In case of a FactoryBean, this callback will be invoked for both the FactoryBean instance and the objects created by the FactoryBean (as of Spring 2.0). The post-processor can decide whether to apply to either the FactoryBean or created objects or both through corresponding bean instanceof FactoryBean checks.

This callback will also be invoked after a short-circuiting triggered by a InstantiationAwareBeanPostProcessor.postProcessBeforeInstantiation(java.lang.Class, java.lang.String) method, in contrast to all other BeanPostProcessor callbacks.

Specified by:
postProcessAfterInitialization in interface BeanPostProcessor
Parameters:
bean - the new bean instance
beanName - the name of the bean
Returns:
the bean instance to use, either the original or a wrapped one
Throws:
BeansException - in case of errors
See Also:
InitializingBean.afterPropertiesSet(), FactoryBean

getPersistenceUnit

protected javax.persistence.EntityManagerFactory getPersistenceUnit(String unitName)
Return a specified persistence unit for the given unit name, as defined through the "persistenceUnits" map.

Parameters:
unitName - the name of the persistence unit
Returns:
the corresponding EntityManagerFactory, or null if none found
See Also:
setPersistenceUnits(java.util.Map)

getPersistenceContext

protected javax.persistence.EntityManager getPersistenceContext(String unitName,
                                                                boolean extended)
Return a specified persistence context for the given unit name, as defined through the "persistenceContexts" (or "extendedPersistenceContexts") map.

Parameters:
unitName - the name of the persistence unit
extended - whether to obtain an extended persistence context
Returns:
the corresponding EntityManager, or null if none found
See Also:
setPersistenceContexts(java.util.Map), setExtendedPersistenceContexts(java.util.Map)

findEntityManagerFactory

protected javax.persistence.EntityManagerFactory findEntityManagerFactory(String unitName)
                                                                   throws NoSuchBeanDefinitionException
Find an EntityManagerFactory with the given name in the current Spring application context, falling back to a single default EntityManagerFactory (if any) in case of no unit name specified.

Parameters:
unitName - the name of the persistence unit (may be null or empty)
Returns:
the EntityManagerFactory
Throws:
NoSuchBeanDefinitionException - if there is no such EntityManagerFactory in the context

findNamedEntityManagerFactory

protected javax.persistence.EntityManagerFactory findNamedEntityManagerFactory(String unitName)
                                                                        throws NoSuchBeanDefinitionException
Find an EntityManagerFactory with the given name in the current Spring application context.

Parameters:
unitName - the name of the persistence unit (never empty)
Returns:
the EntityManagerFactory
Throws:
NoSuchBeanDefinitionException - if there is no such EntityManagerFactory in the context

findDefaultEntityManagerFactory

protected javax.persistence.EntityManagerFactory findDefaultEntityManagerFactory()
Find a single default EntityManagerFactory in the Spring application context.

Returns:
the default EntityManagerFactory
Throws:
NoSuchBeanDefinitionException - if there is no single EntityManagerFactory in the context

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