/***********************************************login.html*****************************************/
<!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>
<form action="/day07/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>
/*************************************LoginServlet***********************************************/
package session;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String name = request.getParameter("username");
String pwd = request.getParameter("password");
List<User> list = Db.getAll();
for(User user:list){
if(user.getName().equals(name) && user.getPassword().equals(pwd)){
//登录成功就是向session存一个登录标记
request.getSession().setAttribute("user", user);//值是user对象
//跳到首页
response.sendRedirect(request.getContextPath()+"/index.jsp");
return;
}
}
out.print("用户名密码不正确");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
class Db{
private static List list = new ArrayList();
static{
list.add(new User("aaa","123"));
list.add(new User("bbb","123"));
list.add(new User("ccc","123"));
}
public static List getAll(){
return list;
}
}
/*****************************************************************index.jsp*******************************************************************8/
<%@ 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>
welcome:${user.name}<a href="/day07/login.html">登录</a><a href="/day07/LogoutServlet">退出登录</a>
</body>
</html>
/***********************************************LogoutServlet*************************************************/
package session;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//注销用户登录
public class LogoutServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session = request.getSession(false);
//先判断session是否为空，空就代表没有用户登录，这是就不做处理，继续跳回到首页
if(session == null){
response.sendRedirect("/day07/index.jsp");
return;
}
//不为空就摧毁session跳回到首页
session.removeAttribute("user");
response.sendRedirect("/day07/index.jsp");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}