javax.persistence

Interface EntityManagerFactory

public interface EntityManagerFactory

Interface used to interact with the entity manager factory for the persistence unit.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the factory, releasing any resources that it holds.
EntityManager	createEntityManager() Create a new application-managed EntityManager.
EntityManager	createEntityManager(Map<String,Object> map) Create a new application-managed EntityManager with the specified Map of properties.
Cache	getCache() Access the cache that is associated with the entity manager factory (the "second level cache").
CriteriaBuilder	getCriteriaBuilder() Return an instance of CriteriaBuilder for the creation of CriteriaQuery objects.
Metamodel	getMetamodel() Return an instance of Metamodel interface for access to the metamodel of the persistence unit.
PersistenceUnitUtil	getPersistenceUnitUtil() Return interface providing access to utility methods for the persistence unit.
Map<String,Object>	getProperties() Get the properties and associated values that are in effect for the entity manager factory.
boolean	isOpen() Indicates whether the factory is open.
<T> T	unwrap(Class<T> cls) Return an object of the specified type to allow access to the provider-specific API.

Method Detail

close

void close()

Close the factory, releasing any resources that it holds. After a factory instance has been closed, all methods invoked on it will throw the IllegalStateException, except for isOpen, which will return false. Once an EntityManagerFactory has been closed, all its entity managers are considered to be in the closed state.

Throws:

IllegalStateException - if the entity manager factory has been closed

createEntityManager

EntityManager createEntityManager()

Create a new application-managed EntityManager. This method returns a new EntityManager instance each time it is invoked. The isOpen method will return true on the returned instance.

Returns:

entity manager instance

Throws:

IllegalStateException - if the entity manager factory has been closed

createEntityManager

EntityManager createEntityManager(Map<String,Object> map)

Create a new application-managed EntityManager with the specified Map of properties. This method returns a new EntityManager instance each time it is invoked. The isOpen method will return true on the returned instance.

Parameters:

map - properties for entity manager

Returns:

entity manager instance

Throws:

IllegalStateException - if the entity manager factory has been closed

getCache

Cache getCache()

Access the cache that is associated with the entity manager factory (the "second level cache").

Returns:

instance of the Cache interface

Throws:

IllegalStateException - if the entity manager factory has been closed

getCriteriaBuilder

CriteriaBuilder getCriteriaBuilder()

Return an instance of CriteriaBuilder for the creation of CriteriaQuery objects.

Returns:

CriteriaBuilder instance

Throws:

IllegalStateException - if the entity manager factory has been closed

getMetamodel

Metamodel getMetamodel()

Return an instance of Metamodel interface for access to the metamodel of the persistence unit.

Returns:

Metamodel instance

Throws:

IllegalStateException - if the entity manager factory has been closed

getPersistenceUnitUtil

PersistenceUnitUtil getPersistenceUnitUtil()

Return interface providing access to utility methods for the persistence unit.

Returns:

PersistenceUnitUtil interface

Throws:

IllegalStateException - if the entity manager factory has been closed

getProperties

Map<String,Object> getProperties()

Get the properties and associated values that are in effect for the entity manager factory. Changing the contents of the map does not change the configuration in effect.

Returns:

properties

Throws:

IllegalStateException - if the entity manager factory has been closed

isOpen

boolean isOpen()

Indicates whether the factory is open. Returns true until the factory has been closed.

Returns:

boolean indicating whether the factory is open

unwrap

<T> T unwrap(Class<T> cls)

Return an object of the specified type to allow access to the provider-specific API. If the provider's EntityManagerFactory implementation does not support the specified class, the PersistenceException is thrown.

Type Parameters:

T - the type of the class

Parameters:

cls - the class of the object to be returned. This is normally either the underlying EntityManagerFactory implementation class or an interface that it implements.

Returns:

an instance of the specified class

Throws:

PersistenceException - if the provider does not support the call