Filter
创建——implements javax.servlet.Filter
@WebFilter(filterName="名"，urlPatterns={"路径1","路径2","路径3","路径4"..........})
实现接口三个方法——init();doFilter();destory();
doFilter(ServletRequest req,ServletResponse resp,FilterChain chain);
获取URI——HttpServletRequest request=(HttpServletRequest)req String uri=request.getRequestURI();
多个filter执行顺序——xml文件内有则按照xml顺序执行，否则按照字母表顺序执行
Listener
创建——implements ServletContextListener,HttpSessionListener,HttpSessionAttributeListener
监听三个对象——ServletContext,HttpSession,ServletRequest
值的改变——implements HttpSessionBindingListener
