使用cookie记录登录名，下次登录时能够记得上次的登录名，使用cookie模拟购物车功能，使用session记住登录信息并验证是否登录，防止利用url打开网站，并实现退出登录功能
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <% //提取checkTaobao.jsp中，cookie保存的淘宝名 Cookie[] cookies=request.getCookies(); String taobaoname=""; if(cookies!=null) { //遍历 for(Cookie c: cookies) { if(c.getName().equals("taobaoname")) { taobaoname=c.getValue(); } } } %> <form action="CheckTaobao.jsp" method="post"> 用户名：<input type="text" name="taobaoname" value="<%=taobaoname%>"><br> 密码：<input type="password" name="taobaopassword"><br> <input type="submit" value="登陆淘宝"><br> </form> <br> <br> </body> </html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <% String taobaoname=request.getParameter("taobaoname"); String taobaopassword=request.getParameter("taobaopassword"); if(taobaoname==null||taobaopassword==null ||taobaoname.equals("")||taobaopassword.equals("")) { out.print("请输入正确的用户名密码"); response.setHeader("refresh", "3;URL=LoginTaobao.jsp"); } else { //连数据库 //验证 if(taobaoname.equals("1234")&&taobaopassword.equals("123456")) { //用cookie记住淘宝名 Cookie cid=new Cookie("taobaoname",taobaoname); cid.setMaxAge(60*60); response.addCookie(cid); //保持登录状态 session.setAttribute("taobaoname",taobaoname);//session是存浏览器的 response.sendRedirect("MainTaobao.jsp"); } else { out.write("用户名密码错误"); response.setHeader("refresh", "3;URL=LoginTaobao.jsp"); } } %> </body> </html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> 淘宝首页 <% Object obj=session.getAttribute("taobaoname"); if(obj==null) { out.write("会话超时或未登录，请重新输入"); response.setHeader("refresh","6;URL=LoginTaobao.jsp"); } else { out.write(obj+",欢迎登录!"); %> <br> <br> <a href="LogoutTaobao.jsp">退出登录</a> <% }%> </body> </html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> 销毁session <% session.invalidate(); out.write("退出成功"); response.setHeader("refresh","3;URL=LoginTaobao.jsp"); %> </body> </html>