javaweb之Session完成用户登录
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>首页</title>
</head>
<body>
<!-- ${user.username}取出session域中的user对象，显示它的username -->
欢迎您：${user.username}
<a href="/day07/login.jsp">登录</a>
<a href="/day07/servlet/LogoutServlet">注销</a>
<br />
<br />
<br />
</body>
</html>
package test.login;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
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;
//用户登陆servlet
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
List<User> list = DB.getAll();
for (User user : list) {
// 如果用户登录成功
if (user.getUsername().equals(username)
&& user.getPassword().equals(password)) {
HttpSession session = request.getSession();
// 手动设置session的有效期为30分钟
String sessionId = session.getId();
Cookie cookie = new Cookie("JSESSIONID", sessionId);
cookie.setMaxAge(60 * 30);
cookie.setPath(request.getContextPath());
response.addCookie(cookie);
// 登录成功后要存入用户的登录状态，key是用户对象的String形式value就是用户对象(model)！！别的页面应该能用到
session.setAttribute("user", user);
// 重定向到首页，URL重写方式
String url = response.encodeRedirectURL(request
.getContextPath() + "/index.jsp");
response.sendRedirect(url);
return;
}
}
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-type", "text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
out.print("用户名或密码错误");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
// 模拟存储用户的数据库
class DB {
private static List<User> list = new ArrayList<User>();
static {
list.add(new User("aaa", "123"));
list.add(new User("bbb", "123"));
list.add(new User("ccc", "123"));
}
public static List<User> getAll() {
return list;
}
}
package test.login;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//注销servlet
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-type", "text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession(false);
if (session == null) {
// 没登录，重定向到首页
String url = response.encodeRedirectURL(request.getContextPath()
+ "/index.jsp");
response.sendRedirect(url);
return;
}
// 从session中移除登录状态
session.removeAttribute("user");
// 重定向到首页，URL重写方式
String url = response.encodeRedirectURL(request.getContextPath()
+ "/index.jsp");
response.sendRedirect(url);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>用户登录</title> </head> <body> <form action="/day07/servlet/LoginServlet" method="post"> 用户名：<input type="text" name="username" /><br> 密码：<input type="password" name="password" /><br> <input type="submit" value="登录" /> </form> </body> </html>
声明：该文观点仅代表作者本人，牛骨文系教育信息发布平台，牛骨文仅提供信息存储空间服务。
- 上一篇： session维持登录状态的简单例子
- 下一篇： 用PHP表单传递数组
