javax.servlet.http
接口 HttpSessionAttributeListener

所有超级接口：

EventListener

public interface HttpSessionAttributeListener
extends EventListener

Interface for receiving notification events about HttpSession attribute changes.

In order to receive these notification events, the implementation class must be either declared in the deployment descriptor of the web application, annotated with WebListener, or registered via one of the addListener methods defined on ServletContext.

The order in which implementations of this interface are invoked is unspecified.

从以下版本开始：

Servlet 2.3

方法摘要

void	attributeAdded(HttpSessionBindingEvent event) Receives notification that an attribute has been added to a session.
void	attributeRemoved(HttpSessionBindingEvent event) Receives notification that an attribute has been removed from a session.
void	attributeReplaced(HttpSessionBindingEvent event) Receives notification that an attribute has been replaced in a session.

方法详细信息

attributeAdded

void attributeAdded(HttpSessionBindingEvent event)

Receives notification that an attribute has been added to a session.

参数：

event - the HttpSessionBindingEvent containing the session and the name and value of the attribute that was added

attributeRemoved

void attributeRemoved(HttpSessionBindingEvent event)

Receives notification that an attribute has been removed from a session.

参数：

event - the HttpSessionBindingEvent containing the session and the name and value of the attribute that was removed

attributeReplaced

void attributeReplaced(HttpSessionBindingEvent event)

Receives notification that an attribute has been replaced in a session.

参数：

event - the HttpSessionBindingEvent containing the session and the name and (old) value of the attribute that was replaced