Class SharedEntityManagerBean

All Implemented Interfaces:
Aware, BeanFactoryAware, FactoryBean<EntityManager>, InitializingBean

public class SharedEntityManagerBean extends EntityManagerFactoryAccessor implements FactoryBean<EntityManager>, InitializingBean
FactoryBean that exposes a shared JPA EntityManager reference for a given EntityManagerFactory. Typically used for an EntityManagerFactory created by LocalContainerEntityManagerFactoryBean, as direct alternative to a JNDI lookup for a Jakarta EE server's EntityManager reference.

The shared EntityManager will behave just like an EntityManager fetched from an application server's JNDI environment, as defined by the JPA specification. It will delegate all calls to the current transactional EntityManager, if any; otherwise, it will fall back to a newly created EntityManager per operation.

Can be passed to DAOs that expect a shared EntityManager reference rather than an EntityManagerFactory. Note that Spring's JpaTransactionManager always needs an EntityManagerFactory in order to create new transactional EntityManager instances.

Juergen Hoeller
See Also:
  • Constructor Details

    • SharedEntityManagerBean

      public SharedEntityManagerBean()
  • Method Details

    • setEntityManagerInterface

      public void setEntityManagerInterface(Class<? extends EntityManager> entityManagerInterface)
      Specify the EntityManager interface to expose.

      Default is the EntityManager interface as defined by the EntityManagerFactoryInfo, if available. Else, the standard jakarta.persistence.EntityManager interface will be used.

      See Also:
    • setSynchronizedWithTransaction

      public void setSynchronizedWithTransaction(boolean synchronizedWithTransaction)
      Set whether to automatically join ongoing transactions (according to the JPA 2.1 SynchronizationType rules). Default is "true".
    • afterPropertiesSet

      public final void afterPropertiesSet()
      Description copied from interface: InitializingBean
      Invoked by the containing BeanFactory after it has set all bean properties and satisfied BeanFactoryAware, ApplicationContextAware etc.

      This method allows the bean instance to perform validation of its overall configuration and final initialization when all bean properties have been set.

      Specified by:
      afterPropertiesSet in interface InitializingBean
    • getObject

      @Nullable public EntityManager getObject()
      Description copied from interface: FactoryBean
      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.

      Specified by:
      getObject in interface FactoryBean<EntityManager>
      an instance of the bean (can be null)
      See Also:
    • getObjectType

      public Class<? extends EntityManager> getObjectType()
      Description copied from interface: FactoryBean
      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.

      Specified by:
      getObjectType in interface FactoryBean<EntityManager>
      the type of object that this FactoryBean creates, or null if not known at the time of the call
      See Also:
    • isSingleton

      public boolean isSingleton()
      Description copied from interface: FactoryBean
      Is the object managed by this factory a singleton? That is, will FactoryBean.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.

      Specified by:
      isSingleton in interface FactoryBean<EntityManager>
      whether the exposed object is a singleton
      See Also: