session实现登陆/登出效果(初识session基础练习)

程序员文章站 2024-03-20 12:55:28

...

1.在Eclipse下创建项目文件: ActionServlet.java、login.jsp、index.jsp

2.ActionServlet.java代码:

package web03;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@WebServlet("*.do")
public class ActionServlet extends HttpServlet {
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
		
		req.setCharacterEncoding("UTF-8");
		res.setContentType("text/html;charset=utf-8");
		PrintWriter out = res.getWriter();
		
		String uri = req.getRequestURI();
		String action = uri.substring(uri.lastIndexOf("/")+1, uri.lastIndexOf("."));
		HttpSession session = req.getSession();
		System.out.println(session.getId());
		
		if(action.equals("login")){
			String uname = req.getParameter("uname");
			String pwd = req.getParameter("pwd");
			
			if(uname.equals("admin") && pwd.equals("12345")){
				session.setAttribute("uname", uname);
				res.sendRedirect("index.jsp");
			} else {
				req.setAttribute("msg", "用户名或密码错误");
				req.getRequestDispatcher("login.jsp").forward(req, res);
			}
		} else if(action.equals("logout")){
			session.invalidate();
			res.sendRedirect("login.jsp");
		}
		out.close();
	}
}

3.login.jsp代码:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
	String msg = (String)request.getAttribute("msg");
	if(msg == null){
		msg = "";
	}
%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>登陆页面</title>
<style type="text/css">
div{
	/* border: 1px solid #CCC; */
	margin: 0 auto;
	width: 300px;
}
span{
	margin-right: 10px;
}
h1{
	text-align: center;
	width:220px;
	/* border: 1px solid #000; */
}
</style>
</head>
<body>
	<div>
		<h1>登陆</h1>
		<form action="login.do" method="post">
			<h3><%=msg %></h3>
			<p><span>账号:</span><input name="uname" type="text" /></p>
			<p><span>密码:</span><input name="pwd" type="password" /></p>
			<input type="submit" value="Login" />
		</form>
	</div>
</body>
</html>

4.index.jsp代码:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<% 
	Object uname = session.getAttribute("uname");
	if(uname == null){
		response.sendRedirect("login.jsp");
		return;
	}
%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
	<div style="width: 150px; margin: 0 auto;">
		<h1>首页</h1>欢迎您:<%=uname.toString() %><br><br>
		<a href="logout.do"><button>登出</button></a>
	</div>
</body>
</html>

5.在Eclipse中启动Tomcat，localhost:8080/HAHA直接先访index.jsp页面,自己做测试

上一篇： Postfix配置QQ邮箱发邮件

下一篇： NOIP 2004 合并果子