hibernate的session管理

SessionFactory.get CurrentSession 与openSession 的区别
    1. 如果使用的是get CurrentSession 来创建session的话，在commit后，session就自动被关闭了，
         也就是不用再session.close()了。但是如果使用的是openSession 方法创建的session的话，
         那么必须显示的关闭session，也就是调用session.close()方法。这样commit后，session并没有关闭
2. get CurrentSession 的使用可以参见hibernate\hibernate-3.2\doc\tutorial\src项目
3. 使用SessionFactory.get CurrentSession ()需要在hibernate.cfg.xml中如下配置：
   * 如果采用jdbc独立引用程序配置如下：
    <property name="hibernate.current_session_context_class">thread</property>
   * 如果采用了JTA事务配置如下
    <property name="hibernate.current_session_context_class">jta</property>

 

4。Do I still need to configure Hibernate to bind Sessions (hibernate.current_session_context_class=thread) to the thread stack? Does Spring take care of this automatically?

If you use LocalSessionFactoryBean, you don't need to declare hibernate.current_session_context_class=thread, Spring will manage it for you . You only declare that if you're going to encapsulate access to the session factory manually (e.g. HibernateUtil). This is also related to the use of SessionFactory.getCurrentSession().

There is a big difference on how the SessionFactory.getCurrentSession() works on plain hibernate and Spring. If you use Hibernate directly, getCurrentSession() works by returning the current session being used, or it spawns a new session. For the case of Spring (via LocalSessionFactoryBean), the getHibernateTemplate().getCurrentSession() does return the current session being used, but it does not spawn a new one if none is available.

 

5. LocalSessionFactoryBean Set connection release mode "on_close" as default.
 This was the case for Hibernate 3.0; Hibernate 3.1 changed
 it to "auto" (i.e. "after_statement" or "after_transaction").
  However, for Spring's resource management (in particular for
HibernateTransactionManager), "on_close" is the better default.