java数据源。EBJ3会话bean中的getConnection（）

Question

在使用EJB3无状态会话bean时，哪里是获得注入数据源连接的最佳位置？我有一个调用ds的方法。getConnection（），但这种情况每次都会发生，因此为每次调用打开和关闭连接既不经济也不明智

通常最好将数据源连接的访问和关闭放在托管生命周期方法中吗？我希望确保以尽可能低的成本访问数据源，同时确保在不再需要连接时关闭连接，这样它就不会只是挂起打开

谢谢

Answer 1

The Lifecycle of a Stateless Session Bean

Because a stateless session bean is never passivated, its lifecycle has only two stages: nonexistent and ready for the invocation of business methods. Figure 22-4 illustrates the stages of a stateless session bean.

The EJB container typically creates and maintains a pool of stateless session beans, beginning the stateless session bean’s lifecycle. The container performs any dependency injection and then invokes the method annotated @PostConstruct, if it exists. The bean is now ready to have its business methods invoked by a client.

At the end of the lifecycle, the EJB container calls the method annotated @PreDestroy, if it exists. The bean’s instance is then ready for garbage collection.

Source: http://docs.oracle.com/javaee/6/tutorial/doc/giplj.html

在EJB中创建一个字段来存储在@PostConstruct获得的连接实例，然后在@PreDestroy中释放它

下面是这个http://theopentutorials.com/tutorials/java-ee/ejb3/session-beans/slsb/stateless-session-beans-lifecycle-callback-methods/的编写代码示例