过滤器等技术实现在线用户信息显示

package filter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import bean.Unline; public class OnlineFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse resp = (HttpServletResponse) response; String servletPath = req.getServletPath(); Unline ul = new Unline(); ul.setId(req.getSession().getId()); ul.setIp(req.getRemoteAddr()); ul.setUname("匿名用户"); ul.setUtype("匿名用户"); req.setAttribute(req.getSession().getId(), ul); if ("/login.jsp".equals(servletPath) && "/login.do".equals(servletPath)) { chain.doFilter(req, resp); return; } if (req.getSession().getAttribute(req.getSession().getId()) == null){ Cookie[] cookies = req.getCookies(); if (cookies != null && cookies.length > 0) { for (Cookie cookie : cookies) { if (cookie.getName().equals(req.getSession().getId())) { ul.setId(cookie.getValue().split(" ")[0]); ul.setUname(cookie.getValue().split(" ")[1]); ul.setPwd(cookie.getValue().split(" ")[2]); ul.setIp(cookie.getValue().split(" ")[3]); ul.setUtype("登陆用户"); req.getSession().setAttribute(req.getSession().getId(),ul); chain.doFilter(req, resp); return; } break; } } req.getSession().setAttribute(req.getSession().getId(), ul); chain.doFilter(req, resp); }else { chain.doFilter(req, resp); } } public void init(FilterConfig arg0) throws ServletException { System.out.println("LoginFilter..."); } }