Java Web 04-6: 处理登录成功后的跳转

/* LoginServlet*/

User user = service.login(username, password);
        if (user != null) {
            req.getSession().setAttribute("user", user);
            
            if(user.isAdmin()) {
                //req.getRequestDispatcher("/admin/goods_list.jsp").forward(req, resp);
　　　　　　　　　　resp.sendRedirect(req.getContextPath()+"/admin/goods_list.jsp");
            }else {
                req.getRequestDispatcher("/").forward(req, resp); // 跳转到首页
            }
        }else {
            req.setAttribute("msg", "<font color='red'>用户名或密码错误,请重新登录!</font>");
            req.getRequestDispatcher("/login.jsp").forward(req, resp);
        }

/*  index */

<%
　　Object user = session.getAttribute("user");
　　if(user == null){
%>
　　<a href="<%=request.getContextPath()%>/login.jsp">登录</a>
　　<a href="<%=request.getContextPath()%>/register.jsp">注册</a>
<%
　　}else{
　　out.println("当前登录用户:"+((User)user).getUsername());
　　}
%>