我爱Java系列---【登录案例】

一、登录案例分析

二、实施流程

1.创建数据库web01,用户表user

代码：

CREATE DATABASE web01;
USE web01;
CREATE TABLE USER(
uid INT PRIMARY KEY AUTO_INCREMENT,
userName VARCHAR(32),
PASSWORD VARCHAR(32)
);

2.在idea中创建User类

public class User {

int uid;
String userName;
String passWord;

public int getUid() {
return uid;
}

public String getUserName() {
return userName;
}

public String getPassWord() {
return passWord;
}

public void setUid(int uid) {
this.uid = uid;
}

public void setUserName(String userName) {
this.userName = userName;
}

public void setPassWord(String passWord) {
this.passWord = passWord;
}

@Override
public String toString() {
return "User{" +
"uid=" + uid +
", userName='" + userName + '\'' +
", passWord='" + passWord + '\'' +
'}';
}
}

3.创建UserDao类

public class UserDao {
    @Test
   /* public void run() throws SQLException {
        User u = query("hujunwei", "123");
        System.out.println(u);
    }*/
    public User queryByuserNameandPassword(String userName,String passWord) throws SQLException {
        QueryRunner qr = new QueryRunner(C3P0Utils.getDS());
        String sql = "select * from user where userName=? and passWord=?";
        User query = qr.query(sql, new BeanHandler<User>(User.class), userName, passWord);
        return query;
    }
}

4.创建Service类

public class Service {
    UserDao userDao = new UserDao();
    public boolean login(String userName,String passWord)  {

        User user = null;
        try {
            user = userDao.queryByuserNameandPassword(userName, passWord);
            return user!=null;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false;
    }
}

5.创建LoginServlet

@WebServlet(urlPatterns = "/login")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        String userName = request.getParameter("userName");
        String passWord = request.getParameter("passWord");
        Service service = new Service();
        boolean login = service.login(userName, passWord);
        if (login){
            response.getWriter().println("登录成功！");
        }else {
            response.getWriter().println("登录失败！");
        }
    }
}

6.创建页面login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>黑马商城</title>
</head>
<body>
<form action="/web01/login" method="post">
    <div>
    用户名：<input type="text" name="userName" value="" placeholder="请输入用户名"></br>
    密　码：<input type="password" name="passWord" value="" placeholder="请输入密码"></br>
            <input type="submit"  value="登录" >
    </div>
</form>
</body>
</html>