超市訂單管理系統，登錄功能實現（完整版）

本文轉載自查看原文 2020-10-12 19:44 855 超市訂單管理系統（java原生代碼實現）

1.規划登錄實現原理流程圖

2.編寫前端頁面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>系統登錄 - 超市訂單管理系統</title>
    <link type="text/css" rel="stylesheet" href="${pageContext.request.contextPath }/css/style.css" />
    <script type="text/javascript">
    /* if(top.location!=self.location){
          top.location=self.location;
     } */
    </script>
</head>
<body class="login_bg">
    <section class="loginBox">
        <header class="loginHeader">
            <h1>超市訂單管理系統</h1>
        </header>
        <section class="loginCont">
            <form class="loginForm" action="${pageContext.request.contextPath }/login.do"  name="actionForm" id="actionForm"  method="post" >
                <div class="info">${error }</div>
                <div class="inputbox">
                    <label for="userCode">用戶名：</label>
                    <input type="text" class="input-text" id="userCode" name="userCode" placeholder="請輸入用戶名" required/>
                </div>    
                <div class="inputbox">
                    <label for="userPassword">密碼：</label>
                    <input type="password" id="userPassword" name="userPassword" placeholder="請輸入密碼" required/>
                </div>    
                <div class="subBtn">
                    
                    <input type="submit" value="登錄"/>
                    <input type="reset" value="重置"/>
                </div>    
            </form>
        </section>
    </section>
</body>
</html>
<!--此僅僅是js，想要完整的評論留郵箱-->

3. 設置首頁（登錄頁），將tomcat默認的index改成自己設計的首頁

   <!--設置歡迎頁面-->
    <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>

4.編寫dao層登錄用戶的接口

package com.king.dao.user;

import com.king.pojo.User;

import java.sql.Connection;
import java.sql.SQLException;

//面向接口編程，接口是一種約束,要用對應類去實現
public interface UserDao {

    //得到要登陸的用戶
    public User getLoginUser(Connection connection,String usercode) throws SQLException;
}

5，編寫登錄接口的實現類

package com.king.dao.user;

import com.king.dao.BaseDao;
import com.king.pojo.User;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

//實現類，實現接口的方法
public class UserDaoImpl implements UserDao{
    public User getLoginUser(Connection connection, String userCode) throws SQLException {

        PreparedStatement pstm=null;
        ResultSet rs=null;
        User user=null;

        if (connection!=null){
            String sql="select * from smbms_user where userCode=?";
            Object[] params={userCode};

                rs = BaseDao.execute(connection, pstm, rs, sql, params);

                if(rs.next()){
                    user = new User();
                    user.setId(rs.getInt("id"));
                    user.setUserCode(rs.getString("userCode"));
                    user.setUserName(rs.getString("userName"));
                    user.setUserPassword(rs.getString("userPassword"));
                    user.setGander(rs.getInt("gender"));
                    user.setBirthday(rs.getDate("birthday"));
                    user.setPhone(rs.getString("phone"));
                    user.setAddress(rs.getString("address"));
                    user.setUserRole(rs.getInt("userRole"));
                    user.setCreatedBy(rs.getInt("createBy"));
                    user.setCreationDate(rs.getTimestamp("creationDate"));
                    user.setModifyBy(rs.getInt("modifyBy"));
                    user.setModifyDate(rs.getTimestamp("modifyDate"));
                }
                BaseDao.closeResource(null,pstm,rs);

        }

        return user;


    }
}

6.業務層接口

package com.king.service.user;

import com.king.pojo.User;

public interface UserService {
    //用戶登錄
    public User login(String userCode,String password);
}

7業務層接口實現類

package com.king.service.user;

import com.king.dao.BaseDao;
import com.king.dao.user.UserDao;
import com.king.dao.user.UserDaoImpl;
import com.king.pojo.User;

import java.sql.Connection;
import java.sql.SQLException;

public class UserServiceImpl implements UserService{

    //業務層都會調用dao層，所以要引入dao層
    private UserDao userDao;

    public UserServiceImpl(){
        userDao=new UserDaoImpl();
    }

    public User login(String userCode, String password) {
        Connection connection=null;
        User user=null;

        try {
            connection= BaseDao.getConnection();
            //通過業務層調用對應的dao層
            user = userDao.getLoginUser(connection, userCode);

        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            BaseDao.closeResource(connection,null,null);
        }
        return user;
    }


 }

8 編寫servlet層，與業務層連接實現數據交互

package com.king.servlet.user;

import com.king.pojo.User;
import com.king.service.user.UserService;
import com.king.service.user.UserServiceImpl;
import com.king.util.Constants;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class LoginServlet extends HttpServlet {

    //Servlet:控制層，調用業務層代碼

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        System.out.println("LoginServlet--start...");

        //獲取用戶名和密碼
        String userCode= req.getParameter("userCode");
        String userPassword= req.getParameter("userPassword");

        //和數據庫中的密碼進行對比，調用業務層來實現
        UserService userService = new UserServiceImpl();
        User user = userService.login(userCode, userPassword);//已經把登錄的人給查出來了

        if (user != null&&user.getUserPassword().equals((String) userPassword)){//找到數據，可以登錄
            //將用戶的信息放入session中
            //為什么放session，區分用戶角色，比如管理員，和普通用戶
            req.getSession().setAttribute(Constants.USER_SESSION,user);//鍵值對的形式
            //跳轉到主頁
            resp.sendRedirect("jsp/frame.jsp");
        }else {//查無此人無法登錄
                //轉發會登陸頁面，同時提示錯誤
            req.setAttribute("error","用戶名或密碼不正確");
            req.getRequestDispatcher("login.jsp").forward(req,resp);
        }



    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

9 注冊servlet

<!--Servlet-->
    <servlet>
        <servlet-name>LoginServlet</servlet-name>
        <servlet-class>com.king.servlet.user.LoginServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LoginServlet</servlet-name>
        <url-pattern>/login.do</url-pattern>
    </servlet-mapping>
    <!--字符編碼過濾器-->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>com.king.filter.CharacterEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!--設置歡迎頁面-->
    <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>

10，注銷功能

package com.king.servlet.user;

import com.king.util.Constants;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class LogoutServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //移除用戶的Constants.USER_SESSION
        req.getSession().removeAttribute(Constants.USER_SESSION);
        resp.sendRedirect("/login.jsp");//返回登陸頁面
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

web配置，

<servlet>
        <servlet-name>LogoutServlet</servlet-name>
        <servlet-class>com.king.servlet.user.LogoutServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LogoutServlet</servlet-name>
        <url-pattern>jsp/logout.do</url-pattern>
    </servlet-mapping>

免責聲明！

本站轉載的文章為個人學習借鑒使用，本站對版權不負任何法律責任。如果侵犯了您的隱私權益，請聯系本站郵箱yoyou2525@163.com刪除。