用来判断cookie有没有值
package com.bdit;
import javax.servlet.http.Cookie;
public class DBCookie {
public static Cookie getCookie(Cookie[] cookies,String key){
if(cookies!=null&&cookies.length>0){
for(Cookie cookie:cookies){
if(cookie.getName().equals(key)){
return cookie;
}
}
}
return null;
}
}
servlet
package com.bdit.servlet;
import com.bdit.sevice.TreeSevice;
import com.bdit.vo.Tree;
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 java.io.IOException;
@WebServlet(urlPatterns = {"/treeServlet"})
public class TreeServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@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 pass=req.getParameter("pass");
String hobby=req.getParameter("hobby");
String hobby2=req.getParameter("hobby2");
TreeSevice sevice=new TreeSevice();
//根据用户名和密码查找
Tree tree=sevice.find(username,pass);
if(tree!=null&&tree.getUsername().equals(username)&&tree.getPass().equals(pass)){
if(hobby2!=null&&hobby2.equals("2")){
if(hobby!=null&&hobby.equals("1")){
Cookie cookie1=new Cookie("username",username);
Cookie cookie2=new Cookie("pass",pass);
cookie1.setPath(req.getContextPath());
cookie2.setPath(req.getContextPath());
cookie1.setMaxAge(60*60*24);
cookie2.setMaxAge(60*60*24);
resp.addCookie(cookie1);
resp.addCookie(cookie2);
Cookie cookie3=new Cookie("hobby","checked");
cookie3.setPath(req.getContextPath());
cookie3.setMaxAge(60*60*24);
resp.addCookie(cookie3);
Cookie cookie4=new Cookie("hobby2","checked");
cookie4.setPath(req.getContextPath());
cookie4.setMaxAge(15);
resp.addCookie(cookie4);
resp.sendRedirect("success.jsp");
}
else{
resp.sendRedirect("success.jsp");
}
}else{
if(hobby!=null&&hobby.equals("1")) {
Cookie cookie1 = new Cookie("username", username);
Cookie cookie2 = new Cookie("pass", pass);
cookie1.setPath(req.getContextPath());
cookie2.setPath(req.getContextPath());
cookie1.setMaxAge(60 * 60 * 24);
cookie2.setMaxAge(60 * 60 * 24);
resp.addCookie(cookie1);
resp.addCookie(cookie2);
Cookie cookie3 = new Cookie("hobby", "checked");
cookie3.setPath(req.getContextPath());
cookie3.setMaxAge(60 * 60 * 24);
resp.addCookie(cookie3);
}else{
resp.sendRedirect("success.jsp");
}
}
}else if(tree==null){
resp.sendRedirect("error.jsp");
}
}
}
主页面index.jsp
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2020/10/20
Time: 21:10
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="com.bdit.DBCookie" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<%
String username="";
String pass="";
String hobby="";
String hobby2="";
Cookie cookie4=DBCookie.getCookie(request.getCookies(),"hobby2");
if(cookie4!=null){
Cookie cookie5=DBCookie.getCookie(request.getCookies(),"hobby");
if(cookie5!=null){
Cookie cookie1= DBCookie.getCookie(request.getCookies(),"username");
if(cookie1!=null){
username=cookie1.getValue();
}
Cookie cookie2=DBCookie.getCookie(request.getCookies(), "pass");
if(cookie2!=null){
pass=cookie2.getValue();
}
hobby=cookie5.getValue();
}
hobby2=cookie4.getValue();
}else{
Cookie cookie3=DBCookie.getCookie(request.getCookies(),"hobby");
if(cookie3!=null){
Cookie cookie1= DBCookie.getCookie(request.getCookies(),"username");
if(cookie1!=null){
username=cookie1.getValue();
}
Cookie cookie2=DBCookie.getCookie(request.getCookies(), "pass");
if(cookie2!=null){
pass=cookie2.getValue();
}
hobby=cookie3.getValue();
}
}
%>
<form action="treeServlet" method="post">
账号：<input type="text" name="username" value=<%=username%> ><br>
密码：<input type="text" name="pass" value=<%=pass%> ><br>
<input type="radio" name="hobby" <%=hobby%> value="1">记住密码<br>
<input type="radio" name="hobby2" <%=hobby2%> value="2">自动登录<br>
<input type="submit">
<%
if(hobby2.equals("checked")){
response.sendRedirect("treeServlet?username="+username+"&pass="+pass+"");
}
%>
</form>
</body>
</html>
成功页面success.jsp
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2020/10/21
Time: 21:18
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h2>登录成功</h2>
<form action="index.jsp">
<input type="submit" value="返回主页">
</form>
</body>
</html>
失败页面error.jsp
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2020/10/21
Time: 21:19
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h2>登录失败</h2>
<a href="index.jsp">回主页</a>
</body>
</html>
本文地址：https://blog.csdn.net/vlucky_long/article/details/110249647
