public class SharedEntityManagerBean extends EntityManagerFactoryAccessor implements FactoryBean<EntityManager>, InitializingBean
FactoryBeanthat exposes a shared JPA
EntityManagerreference for a given EntityManagerFactory. Typically used for an EntityManagerFactory created by
LocalContainerEntityManagerFactoryBean, as direct alternative to a JNDI lookup for a Java 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
always needs an EntityManagerFactory in order to create new transactional EntityManager instances.
|Constructor and Description|
|Modifier and Type||Method and Description|
Invoked by the containing
Return an instance (possibly shared or independent) of the object managed by this factory.
Return the type of object that this FactoryBean creates, or
Is the object managed by this factory a singleton? That is, will
Specify the EntityManager interface to expose.
Set whether to automatically join ongoing transactions (according to the JPA 2.1 SynchronizationType rules).
createEntityManager, getEntityManagerFactory, getJpaPropertyMap, getPersistenceUnitName, getTransactionalEntityManager, obtainEntityManagerFactory, setBeanFactory, setEntityManagerFactory, setJpaProperties, setJpaPropertyMap, setPersistenceUnitName
public void setEntityManagerInterface(Class<? extends EntityManager> entityManagerInterface)
Default is the EntityManager interface as defined by the
EntityManagerFactoryInfo, if available. Else, the standard
javax.persistence.EntityManager interface will be used.
public void setSynchronizedWithTransaction(boolean synchronizedWithTransaction)
public final void afterPropertiesSet()
BeanFactoryafter it has set all bean properties and satisfied
This method allows the bean instance to perform validation of its overall configuration and final initialization when all bean properties have been set.
@Nullable public EntityManager getObject()
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
As of Spring 2.0, FactoryBeans are allowed to return
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.
public Class<? extends EntityManager> getObjectType()
nullif 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.
nullif not known at the time of the call
public boolean isSingleton()
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
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
may explicitly indicate independent instances through its
SmartFactoryBean.isPrototype() method. Plain
implementations which do not implement this extended interface are
simply assumed to always return independent instances if the
isSingleton() implementation returns
The default implementation returns
true, since a
FactoryBean typically manages a singleton instance.