EntityManagerFactory (Java EE 5)

The EntityManagerFactory interface is used by the application to obtain an application-managed entity manager. 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

public EntityManager createEntityManager()
创建新的 EntityManager。每次调用此方法时都返回一个新的 EntityManager 实例。isOpen 方法将对返回的实例返回 true。

英文文档：

createEntityManager

EntityManager createEntityManager()

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

public EntityManager createEntityManager(java.util.Map<K, V> map)
创建带指定属性 Map 的新 EntityManager。每次调用此方法时都返回一个新的 EntityManager 实例。isOpen 方法将对返回的实例返回 true。

英文文档：

createEntityManager

EntityManager createEntityManager(Map map)

Create a new 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.

public void close()
关闭工厂，释放它占用的所有资源。关闭工厂实例之后，对其调用的所有方法都将抛出 IllegalStateException（isOpen 除外，它返回 false）。关闭 EntityManagerFactory 后，它的所有实体管理器应该视为处于已关闭状态。

英文文档：

close

void close()

Close the factory, releasing any resources that it holds. After a factory instance is closed, all methods invoked on it will throw an 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.

public boolean isOpen()
指示此工厂是否处于打开状态。在调用 close 之前返回 true。

英文文档：

isOpen

boolean isOpen()

Indicates whether or not this factory is open. Returns true until a call to close has been made.

Copyright 2007 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.