利用Cookie实现 记住用户名

Login：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html;charset=UTF-8");PrintWriter writer = response.getWriter();String username = "";String checked = "";//得到客户端的Cookie数据Cookie[] cookies = request.getCookies();for (int i = 0; cookies!=null && i < cookies.length; i++) {if("username".equals(cookies[i].getName())){username = cookies[i].getValue();checked = "checked='checked'";}}writer.print("<form action='"+request.getContextPath()+"/DoLogin' method='POST'>");writer.print("用户名:<input type='text' name='username' value='"+username+"' /><br/>");writer.print("密  码:<input type='password' name='password'/><br/>");writer.print("<input type='checkbox' name='remember' "+checked+"/> 是否记住用户名<br/>");writer.print("<input type='submit' value='登录'/>");writer.print("</form>");}

DoLogin:

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=UTF-8");PrintWriter writer = response.getWriter();//获取表单数据String username = request.getParameter("username");String password = request.getParameter("password");String remember = request.getParameter("remember");Cookie cookie = new Cookie("username",username);cookie.setPath("/");if("admin".equals(username) && "123".equals(password)){if(remember != null){cookie.setMaxAge(Integer.MAX_VALUE);}else{cookie.setMaxAge(0); //删除cookie}response.addCookie(cookie);writer.println("登录成功！");}else{writer.println("登录失败");//设置两秒钟后跳转道登录页面response.setHeader("refresh","2;url="+request.getContextPath()+"/Login");}}