Cookie实例——记住用户名

篇首语：本文由编程笔记#小编为大家整理，主要介绍了COOKIE实例——记住用户名相关的知识，希望对你有一定的参考价值。

1.简单流程图

2.利用代码实现

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
response.setContentType("text/html;charset&＃61;UTF-8");
PrintWriter out &＃61; response.getWriter();
String userName &＃61;"";
String checked &＃61; "";
//得到客户端保存的COOKIE数据
COOKIE[] COOKIEs &＃61; request.getCOOKIEs();
for (int i &＃61; 0;COOKIEs!&＃61;null && i if("userName".equals(COOKIEs[i].getName()))
userName &＃61; COOKIEs[i].getValue();
checked &＃61; "checked&＃61;&＃39;checked&＃39;";



out.write("");
out.write("用户名&＃xff1a;
");
out.write("密码&＃xff1a;
");
out.write("记住用户名
");
out.write("
");
out.write("");


再新建一个DoLogin方法

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset&＃61;UTF-8");
PrintWriter out &＃61; response.getWriter();
//获取表单数据
String userName &＃61; request.getParameter("userName");
String pwd &＃61; request.getParameter("pwd");
String remember &＃61; request.getParameter("remember");

COOKIE ck &＃61; new COOKIE("userName", userName);
ck.setPath("/");
//处理业务逻辑
//分发转向
if("tom".equals(userName)&&"123".equals(pwd))
if(remember!&＃61;null)
ck.setMaxAge(Integer.MAX_VALUE);//设置COOKIE的有效保存时间
else
ck.setMaxAge(0);//删除 COOKIE

response.addCOOKIE(ck);//将COOKIE写回到客户端
out.write("登录成功&＃xff01;");
else
out.write("登录失败&＃xff01;");
//设置2秒跳到重新登录
response.setHeader("refresh", "2;url&＃61;"&＃43;request.getContextPath()&＃43;"/servlet/Login");



得到的结果为&＃xff1a;

登录后显示成功登录

再次访问时&＃xff0c;“用户名”和“登录用户名”均自动填充

3.总结