监听器 Listener
.ServletContextListener·HttpSessionListener·servletRequestListener
作用:能够针对创建和销毁定又不网的行为
ServletContextListener
coverride
public void contextInitialized(ServletContextEvent sce){
)
coverride
public void contextoestroyed(ServletContextEvent sce){
)
HttpSessionListener
Goverride
public void sessioncreated(HttpsessionEvent se){
}
Coverride
public void sessionDestroyed(HttpsessionEvent se)(
1
一定要在监听器的类上加上webListener，否则该监听器不会被启动
过滤器 Filter
精准匹配 /a.jsp
扩展名匹配*.jsp
路径匹配/manager/*
匹配所有/*
public void doFilter(request,respose,chain) throws IOException,ServletException{
}
