基于day17_base项目
1 package com.haifei.web.filter; 2 3 import javax.servlet.*; 4 import javax.servlet.annotation.WebFilter; 5 import javax.servlet.http.HttpServletRequest; 6 import java.io.IOException; 7 8 /** 9 * 用户登录验证的过滤器 10 */ 11 @WebFilter("/*") 12 public class LoginFilter implements Filter { 13 public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException { 14 //1 强转转换 15 HttpServletRequest request = (HttpServletRequest)req; 16 17 //2 获取资源请求路径 18 String uri = request.getRequestURI(); 19 20 //3 判断是否包含登录相关资源,注意也要排除掉css/js/图片/验证码等资源 21 if (uri.contains("/login.jsp") || uri.contains("/LoginServlet") || uri.contains("/CheckCodeServlet") || uri.contains("/css/") || uri.contains("/js/") || uri.contains("/fonts/")){ 22 //包含 --> 用户欲登录 --> 放行 23 chain.doFilter(req, resp); 24 }else { 25 //不包含 --> 判断用户是否已登录 26 27 //4 从session中获取user 28 Object user = request.getSession().getAttribute("user"); 29 if (user != null){ 30 //已登录 --> 放行 31 chain.doFilter(req, resp); 32 }else { 33 //未登录 --> 跳转到登录页面 34 request.setAttribute("login_msg", "您尚未登录,请登录!"); 35 request.getRequestDispatcher("/login.jsp").forward(request, resp); 36 } 37 } 38 } 39 40 public void init(FilterConfig config) throws ServletException { 41 42 } 43 44 public void destroy() { 45 46 } 47 48 }