/**
* A ServletRequestListener can be implemented by the developer
* interested in being notified of requests coming in and out of
* scope in a web component. A request is defined as coming into
* scope when it is about to enter the first servlet or filter
* in each web application, as going out of scope when it exits
* the last servlet or the first filter in the chain.
*
* @since Servlet 2.4
*/
//Servlet请求监听器，开发者可以实现这个接口来监听请求进入或者离开web应用
public interface ServletRequestListener extends EventListener {
/** The request is about to go out of scope of the web application. */
//Request销毁监听
public void requestDestroyed ( ServletRequestEvent sre );
/** The request is about to come into scope of the web application. */
//Request初始化监听
public void requestInitialized ( ServletRequestEvent sre );
}
/**
* A ServletRequestAttributeListener can be implemented by the
* developer interested in being notified of request attribute
* changes. Notifications will be generated while the request
* is within the scope of the web application in which the listener
* is registered. A request is defined as coming into scope when
* it is about to enter the first servlet or filter in each web
* application, as going out of scope when it exits the last servlet
* or the first filter in the chain.
*
* @since Servlet 2.4
*/
//servlet 请求参数监听器，开发者可以实现这个接口来通知属性的改变
public interface ServletRequestAttributeListener extends EventListener {
/** Notification that a new attribute was added to the
** servlet request. Called after the attribute is added.
*/
//属性添加监听
public void attributeAdded(ServletRequestAttributeEvent srae);
/** Notification that an existing attribute has been removed from the
** servlet request. Called after the attribute is removed.
*/
//属性删除监听
public void attributeRemoved(ServletRequestAttributeEvent srae);
/** Notification that an attribute was replaced on the
** servlet request. Called after the attribute is replaced.
*/
//属性替代监听
public void attributeReplaced(ServletRequestAttributeEvent srae);
}