02.登录注册注销案例-LoginServlet实现

LoginServlet.java

package com.exp.web.servlet;

import java.io.IOException;

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 com.exp.domain.User;
import com.exp.service.IUserService;
import com.exp.service.impl.UserServiceImpl;

@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        response.setHeader("content-type", "text/html;charset=utf-8");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        
        IUserService userDao = new UserServiceImpl();
        User user = userDao.login(username,password);
        
        if(user != null){//登陆成功
            //登陆用户存储到session中
            request.getSession().setAttribute("user", user);
            response.sendRedirect(request.getContextPath()+"/main.jsp");
        }else{
            //登陆失败
            response.getWriter().write("用户名或者密码不正确~");
        }
        
    }

}

<%@ 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>
    <form action="${pageContext.request.contextPath}/LoginServlet"  methhod='get'>
        <table border='1'>
            <tr>
                <td>用户名：</td>
                <td><input type='text' name='username' placeholder="请输入用户名"/></td>
            </tr>
            <tr>
                <td>密码：</td>
                <td><input type='text' name='password' placeholder="请输入密码"/></td>
            </tr>
            <tr>
                <td  colspan='2'><input type='submit'  value='登录'/></td>
            </tr>
        </table>    
    </form>.
</body>
</html>