利用Cookie、Session写的登录页面、成功页面、退出页面

package com.zhiyou.session.demo; import java.io.IOException; import java.net.URLDecoder; import java.net.URLEncoder; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; @WebServlet("/LoginServlet") public class LoginServlet extends HttpServlet{ @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("UTF-8"); resp.setContentType("text/html;charset=UTF-8"); String userName=req.getParameter("userName"); String pwd=req.getParameter("pwd"); // String uName=URLDecoder.decode(userName); if("张三".equals(userName) && "123456".equals(pwd)){ HttpSession session=req.getSession(); session.setAttribute("userName", userName); //Cookie的使用 String uName=URLEncoder.encode(userName); Cookie cookie=new Cookie("cookieUserName",uName); resp.addCookie(cookie); // req.setAttribute("userName", userName); System.out.println("req.getContextPath():"+req.getContextPath()); resp.sendRedirect(req.getContextPath()+"/index.jsp"); }else{ resp.sendRedirect(req.getContextPath()+"/error.jsp"); } } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } }