javax.persistence
Interface EntityManagerFactory

public interface EntityManagerFactory

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

When the application has finished using the entity manager factory, and/or at application shutdown, the application should close the entity manager factory. Once an EntityManagerFactory has been closed, all its entity managers are considered to be in the closed state.

Since:

Java Persistence 1.0

Method Summary

void	addNamedQuery(java.lang.String name, Query query) Define the query, typed query, or stored procedure query as a named query such that future query objects can be created from it using the createNamedQuery methods.
void	close() Close the factory, releasing any resources that it holds.
EntityManager	createEntityManager() Create a new application-managed EntityManager.
EntityManager	createEntityManager(java.util.Map 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.
java.util.Map<java.lang.String,java.lang.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(java.lang.Class<T> cls) Return an object of the specified type to allow access to the provider-specific API.

Method Detail

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:

java.lang.IllegalStateException - if the entity manager factory has been closed

createEntityManager

EntityManager createEntityManager(java.util.Map 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:

java.lang.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:

java.lang.IllegalStateException - if the entity manager factory has been closed

Since:

Java Persistence 2.0

getMetamodel

Metamodel getMetamodel()

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

Returns:

Metamodel instance

Throws:

java.lang.IllegalStateException - if the entity manager factory has been closed

Since:

Java Persistence 2.0

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

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:

java.lang.IllegalStateException - if the entity manager factory has been closed

getProperties

java.util.Map<java.lang.String,java.lang.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:

java.lang.IllegalStateException - if the entity manager factory has been closed

Since:

Java Persistence 2.0

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:

java.lang.IllegalStateException - if the entity manager factory has been closed

Since:

Java Persistence 2.0

getPersistenceUnitUtil

PersistenceUnitUtil getPersistenceUnitUtil()

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

Returns:

PersistenceUnitUtil interface

Throws:

java.lang.IllegalStateException - if the entity manager factory has been closed

Since:

Java Persistence 2.0

addNamedQuery

void addNamedQuery(java.lang.String name,
                   Query query)

Define the query, typed query, or stored procedure query as a named query such that future query objects can be created from it using the createNamedQuery methods. Any configuration of the query object (except for actual parameter binding) in effect when the named query is added is retained as part of the named query definition. This includes configuration information such as max results, hints, flush mode, lock mode, result set mapping information, and information about stored procedure parameters. When the query is executed, information that can be set by means of the Query API can be overridden. Information that is overridden does not affect the named query as registered with the entity manager factory, and thus does not affect subsequent query objects created from it by means of the createNamedQuery method. If a named query of the same name has been previously defined, either statically via metadata or via this method, that query definition is replaced.

Parameters:

name - name for the query

query - Query, TypedQuery, or StoredProcedureQuery object

Since:

Java Persistence 2.1

unwrap

<T> T unwrap(java.lang.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.

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