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 Java EE 5 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.
logger
Constructor and Description |
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SharedEntityManagerBean() |
Modifier and Type | Method and Description |
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void |
afterPropertiesSet()
Invoked by a BeanFactory after it has set all bean properties supplied
(and satisfied BeanFactoryAware and ApplicationContextAware).
|
EntityManager |
getObject()
Return an instance (possibly shared or independent) of the object
managed by this factory.
|
Class<? extends EntityManager> |
getObjectType()
Return the type of object that this FactoryBean creates,
or
null if not known in advance. |
boolean |
isSingleton()
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)? |
void |
setEntityManagerInterface(Class<? extends EntityManager> entityManagerInterface)
Specify the EntityManager interface to expose.
|
createEntityManager, getEntityManagerFactory, getJpaPropertyMap, getPersistenceUnitName, getTransactionalEntityManager, 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 final void afterPropertiesSet()
InitializingBean
This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.
afterPropertiesSet
in interface InitializingBean
public EntityManager getObject()
FactoryBean
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.
getObject
in interface FactoryBean<EntityManager>
null
)FactoryBeanNotInitializedException
public Class<? extends EntityManager> getObjectType()
FactoryBean
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.
getObjectType
in interface FactoryBean<EntityManager>
null
if not known at the time of the callListableBeanFactory.getBeansOfType(java.lang.Class<T>)
public boolean isSingleton()
FactoryBean
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
.
isSingleton
in interface FactoryBean<EntityManager>
FactoryBean.getObject()
,
SmartFactoryBean.isPrototype()