public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		//拦截功能启动提示
		System.out.println("===============过滤拦截功能启动==============");
		
		//强转收发类型
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse rep = (HttpServletResponse) response;
		
		//过滤页面提示
		System.out.println("过滤链接url:" + req.getRequestURI());
		System.out.println("过滤方法(GET/POST)method:" + req.getMethod());
		
		//判断过滤放行(static/*下所有文件)方法
		if (req.getRequestURI().startsWith(req.getContextPath() + "/static/")) {
			System.out.println("过滤放行/static/*下所有文件");
			chain.doFilter(request, response);
			return;
		}
		//判断过滤放行login登录页面
		if (req.getRequestURI().equals(req.getContextPath() + "/login")) {
			System.out.println("过滤放行/login登录页面");
			chain.doFilter(request, response);
			return;
		}
		//判断过滤放行validateimage二维码页面
		if (req.getRequestURI().equals(req.getContextPath() + "/validateimage")) {
			System.out.println("过滤放行/validateimage二维码");
			chain.doFilter(request, response);
			return;
		}
		//判断过滤放行POST提交方法
		if (req.getMethod().equals("POST")) {
			System.out.println("过滤放行POST提交方法");
			chain.doFilter(request, response);
			return;
		}
		//判断过滤放行session缓存方法
		if (req.getSession().getAttribute("user") != null) {
			System.out.println("过滤放行Session缓存");
			chain.doFilter(request, response);
			return;
		}
		// 从Cookie获取上次保存的账号和密码
				//取前端Cookie数据
				Cookie[] cks = req.getCookies();
				//判断Cookie是否为空
				if (cks != null) {
					//循环遍历Cookie
					for (Cookie c : cks) {
						//判断Cookie的name为userCookie就执行
						if (c.getName().equals("userCookie")) {
							//按@@分割Cookie的值
							String[] us = c.getValue().split("@@");
							//判断Cookie中账号密码是否正确
							User u = Tools.authenticate(us[0], us[1]);
							//判断返回的集合是否为空
							if (u != null) {
								//Cookie正确提示信息
								System.out.println("Cookie正确设置 session");
								//设置session到服务器
								req.getSession().setAttribute("user", u);
							}
						}
					}
				}
				//判断过滤session是否为空
				if (req.getSession().getAttribute("user") == null) {
					System.out.println("session为空重新加载到：/login页面");
					rep.sendRedirect(req.getContextPath() + "/login");
					return;
				}
				System.out.println("==============doFilter过滤器执行完毕！==============");
                                //过滤放行
		                chain.doFilter(request, response);
	}
}