案例10-用户登录基本功能的实现

1 login.jsp代码

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>会员登录</title>
<link rel="stylesheet" href="css/bootstrap.min.css" type="text/css" />
<script src="js/jquery-1.11.3.min.js" type="text/javascript"></script>
<script src="js/bootstrap.min.js" type="text/javascript"></script>
<!-- 引入自定义css文件 style.css -->
<link rel="stylesheet" href="css/style.css" type="text/css" />

<style>
body {
    margin-top: 20px;
    margin: 0 auto;
}

.carousel-inner .item img {
    width: 100%;
    height: 300px;
}

.container .row div {
    /* position:relative;
                 float:left; */
    
}

font {
    color: #666;
    font-size: 22px;
    font-weight: normal;
    padding-right: 17px;
}
</style>

<script type="text/javascript">
    function changeImg(obj) {
        obj.src="${pageContext.request.contextPath }/checkImg?time="+new Date().getTime();
    }
    
</script>

</head>
<body>

    <!-- 引入header.jsp -->
    <jsp:include page="/header.jsp"></jsp:include>


    <div class="container"
        style=" 100%; height: 460px; background: #FF2C4C url('images/loginbg.jpg') no-repeat;">
        <div class="row">
            <div class="col-md-7">
                <!--<img src="./image/login.jpg" width="500" height="330" alt="会员登录" title="会员登录">-->
            </div>

            <div class="col-md-5">
                <div
                    style=" 440px; border: 1px solid #E7E7E7; padding: 20px 0 20px 30px; border-radius: 5px; margin-top: 60px; background: #fff;">
                    <font>会员登录</font>USER LOGIN
                    <div id="checkCodeInfo" style="color:red">${loginInfo}</div>
                    <form class="form-horizontal" action="${pageContext.request.contextPath }/login" method="post">
                        <div class="form-group">
                            <label for="username" class="col-sm-2 control-label">用户名</label>
                            <div class="col-sm-6">
                                <input type="text" class="form-control" id="username" name="username"
                                    placeholder="请输入用户名">
                            </div>
                        </div>
                        <div class="form-group">
                            <label for="inputPassword3" class="col-sm-2 control-label">密码</label>
                            <div class="col-sm-6">
                                <input type="password" class="form-control" id="inputPassword3" name="password"
                                    placeholder="请输入密码"> 
                            </div>
                        </div>
                        <div class="form-group">
                            <label for="inputPassword3" class="col-sm-2 control-label">验证码</label>
                            <div class="col-sm-3">
                                <input type="text" class="form-control" id="inputPassword3" name="checkCode"
                                    placeholder="请输入验证码">
                            </div>
                            <div class="col-sm-3">
                                <img src="${pageContext.request.contextPath }/checkImg" onclick="changeImg(this)"/>
                            </div>
                        </div>
                        <div class="form-group">
                            <div class="col-sm-offset-2 col-sm-10">
                                <div class="checkbox">
                                    <label> <input type="checkbox"> 自动登录
                                    </label>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <label> <input
                                        type="checkbox"> 记住用户名
                                    </label>
                                </div>
                            </div>
                        </div>
                        <div class="form-group">
                            <div class="col-sm-offset-2 col-sm-10">
                                <input type="submit" width="100" value="登录" name="submit"
                                    style="background: url('./images/login.gif') no-repeat scroll 0 0 rgba(0, 0, 0, 0); height: 35px;  100px; color: white;">
                            </div>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>

    <!-- 引入footer.jsp -->
    <jsp:include page="/footer.jsp"></jsp:include>

</body>
</html>

2 web层LoginServlet

package www.test.web.servlet;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import www.test.domain.User;
import www.test.service.LoginService;

public class LoginServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // 解决乱码问题
        request.setCharacterEncoding("UTF-8");

        // 获得页面输入的验证
        String checkCode_client = request.getParameter("checkCode");
        // 获得生成图片的文字的验证码
        String checkCode_session = (String) request.getSession().getAttribute("checkcode_session");
        // 比对页面的和生成图片的文字的验证码是否一致
        if (!checkCode_session.equals(checkCode_client)) {
            request.setAttribute("loginInfo", "您的验证码不正确");
            request.getRequestDispatcher("/login.jsp").forward(request, response);
            return;
        }
        // 获取用户输入的数据
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        LoginService service = new LoginService();
        User user = null;
        try {
            user = service.findUser(username, password);
        } catch (SQLException e) {

            e.printStackTrace();
        }

        if (user != null) {
            response.sendRedirect("/WEBTest24/index.jsp");
        } else {
            request.setAttribute("loginInfo", "密码或者用户名不正确");
            request.getRequestDispatcher("/login.jsp").forward(request, response);
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }
}

3 service层

package www.test.service;

import java.sql.SQLException;

import www.test.dao.LoginDao;
import www.test.domain.User;

public class LoginService {

    public User findUser(String username, String password) throws SQLException {
        LoginDao dao = new LoginDao();
        return dao.findUser(username,password);
    }

}

4 dao层

package www.test.dao;

import java.sql.SQLException;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;

import www.test.domain.User;
import www.test.utils.C3P0Utils;

public class LoginDao {

    public User findUser(String username, String password) throws SQLException {
        QueryRunner qr = new QueryRunner(C3P0Utils.getDataSource());
        String sql = "select * from user where username =? and password = ?";
        return qr.query(sql, new BeanHandler<User>(User.class), username,password);
        
    }

}
原文地址:https://www.cnblogs.com/jepson6669/p/8407090.html