com.media.bean UserBean

1. com.media.bean UserBean

package com.media.bean;
public class UserBean {
    private int id;
    private String username;
    private String password;
    private int gender;
    private int age;
    private int status;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public int getGender() {
        return gender;
    }
    public void setGender(int gender) {
        this.gender = gender;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public int getStatus() {
        return status;
    }
    public void setStatus(int status) {
        this.status = status;
    }
}

2.com.media.controller LoginController

package com.media.controller;
import com.media.util.DBUtil;
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 javax.servlet.http.HttpSession;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

/**
 * Servlet 注解配置信息
 */
@WebServlet(name = "LoginServlet",value = "/login")
public class LoginController extends HttpServlet {

    /**
     * post请求 会执行doPost方法
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }
    /**
     * get请求 会执行doGet方法
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("servlet 请求");
        request.setCharacterEncoding("utf-8");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        HttpSession session = request.getSession();
        if("1".equals(request.getParameter("invalidate")) && session.getAttribute("username") != null){
            session.invalidate();
            //session.removeAttribute("username");
            response.sendRedirect("login.jsp");
        }
        try {
            Connection connection = DBUtil.getConnection();
            //sql 模板
            String sql = "select * from user where username = ? and password = ?";
            //使用PreparedStatement对象执行sql语句
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1,username);
            ps.setString(2,password);
            ResultSet rs = ps.executeQuery();
            //response.setContentType("text/html;charset=UTF-8");
            PrintWriter out = response.getWriter();
            if(rs.next()){
                //表示登录成功
                session.setAttribute("username",username);
                response.sendRedirect("home.jsp");
            }else{
                //表示登录未成功
                out.print("登录失败,3秒之后跳转登录页面...");
                response.setHeader("refresh","3;url=login.jsp");
            }
            //服务端跳转
            //request.getRequestDispatcher("home.jsp").forward(request,response);
            DBUtil.close(connection,ps,rs);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

3.com.media.controller UserController

package com.media.controller;
import com.media.bean.UserBean;
import com.media.service.UserService;
import com.media.service.impl.UserServiceImpl;
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 java.io.IOException;
import java.sql.SQLException;
@WebServlet("/user")
public class UserController 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 {
        String method = request.getParameter("method");
        UserBean userBean = new UserBean();
        userBean.setUsername(request.getParameter("username"));
        userBean.setPassword(request.getParameter("password"));
        UserService userService = new UserServiceImpl();
        if("addUser".equals(method)){
            try {
                int count = userService.addUser(userBean);
                if(count == 0){
                    response.sendRedirect("");
                }else{
                    response.sendRedirect("home.jsp");
                }
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        if("editUser".equals(method)){
            userBean.setId(Integer.parseInt(request.getParameter("id")));
            userService.editUser(userBean);
        }
        if("deleteUser".equals(method)){
            userService.deleteUserById(Integer.parseInt(request.getParameter("id")));
        }
    }
}

4.com.media.dao.impl UserDaoImpl

package com.media.dao.impl;
import com.media.bean.UserBean;
import com.media.dao.UserDao;
import com.media.util.DBUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class UserDaoImpl implements UserDao {
    @Override
    public UserBean getUserById(int id) {
        UserBean userBean = new UserBean();
        try{
            Connection connection = DBUtil.getConnection();
            String sql = "select * from user where id = ?";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setInt(1,id);
            ResultSet rs = ps.executeQuery();
            if(rs.next()){
                userBean.setId(rs.getInt("id"));
                userBean.setUsername(rs.getString("username"));
                userBean.setPassword(rs.getString("password"));
                userBean.setGender(rs.getInt("gender"));
                userBean.setAge(rs.getInt("age"));
                userBean.setStatus(rs.getInt("status"));
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        return userBean;
    }
    @Override
    public UserBean getUserByName(String username) {
        UserBean userBean = new UserBean();
        try{
            Connection connection = DBUtil.getConnection();
            String sql = "select * from user where username = ?";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1,username);
            ResultSet rs = ps.executeQuery();
            if(rs.next()){
                userBean.setUsername(rs.getString("username"));
                userBean.setPassword(rs.getString("password"));
                userBean.setGender(rs.getInt("gender"));
                userBean.setAge(rs.getInt("age"));
                userBean.setStatus(rs.getInt("status"));
                userBean.setId(rs.getInt("id"));
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        return userBean;
    }
    @Override
    public List<UserBean> getUserList(UserBean user) {
        List<UserBean> userList = new ArrayList<>();
        UserBean userBean = null;
        try{
            Connection connection = DBUtil.getConnection();
            String sql = "select * from user where username like ?";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1,user.getUsername());
            ResultSet rs = ps.executeQuery();
            while (rs.next()){
                userBean = new UserBean();
                userBean.setUsername(rs.getString("username"));
                userBean.setPassword(rs.getString("password"));
                userBean.setGender(rs.getInt("gender"));
                userBean.setAge(rs.getInt("age"));
                userBean.setId(rs.getInt("id"));
                userBean.setStatus(rs.getInt("status"));
                userList.add(userBean);
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        return userList;
    }
    @Override
    public int addUser(UserBean user) throws SQLException {
        Connection connection = DBUtil.getConnection();
        String sql = "inert into user (username,password,age,gender,status) values (?,?,?,?,?)";
        PreparedStatement ps = connection.prepareStatement(sql);
        ps.setString(1,user.getUsername());
        ps.setString(2,user.getPassword());
        ps.setInt(3,user.getAge());
        ps.setInt(4,user.getGender());
        ps.setInt(5,user.getStatus());
        int count = ps.executeUpdate();
        DBUtil.close(connection,ps,null);
        return count;
    }
    @Override
    public int editUser(UserBean user) {
        return 0;
    }
    @Override
    public int deleteUserById(int id) {
        return 0;
    }
}

5.com.media.dao UserDao

package com.media.dao;
import com.media.bean.UserBean;
import java.sql.SQLException;
import java.util.List;
public interface UserDao {
    UserBean getUserById(int id);
    UserBean getUserByName(String username);
    List<UserBean> getUserList(UserBean user);
    int addUser(UserBean user) throws SQLException;
    int editUser(UserBean user);
    int deleteUserById(int id);
}

6.com.media.service.impl UserServiceImpl

package com.media.service.impl;
import com.media.bean.UserBean;
import com.media.dao.UserDao;
import com.media.dao.impl.UserDaoImpl;
import com.media.service.UserService;
import java.sql.SQLException;
import java.util.List;
public class UserServiceImpl implements UserService {
    @Override
    public UserBean getUserById(int id) {
        return null;
    }
    @Override
    public UserBean getUserByName(String username) {
        return null;
    }
    @Override
    public List<UserBean> getUserList() {
        return null;
    }
    @Override
    public int addUser(UserBean user) throws SQLException {
        //业务层 负责业务数据处理
        UserDao userDao = new UserDaoImpl();
        return userDao.addUser(user);
    }
    @Override
    public int editUser(UserBean user) {
        return 0;
    }
    @Override
    public int deleteUserById(int id) {
        return 0;
    }
}

7.com.media.service UserService

package com.media.service;
import com.media.bean.UserBean;
import java.sql.SQLException;
import java.util.List;
public interface UserService {
    UserBean getUserById(int id);
    UserBean getUserByName(String username);
    List<UserBean> getUserList();
    int addUser(UserBean user) throws SQLException;
    int editUser(UserBean user);
    int deleteUserById(int id);
}

8.com.media.util DBUti

package com.media.util;
import java.sql.*;
public class DBUtil {
    public static Connection getConnection(){
        Connection connection = null;
        try {
            //加载数据库驱动
            Class.forName("com.mysql.jdbc.Driver");
            //建立数据库连接
            String url = "jdbc:mysql://localhost:3306/book";
            connection = DriverManager.getConnection(url,"root","root");
        }catch (Exception e){
            e.printStackTrace();
        }
        return connection;
    }
    public static void close(Connection connection, PreparedStatement ps, ResultSet rs){
        //关闭数据库连接
        if(rs != null){
            try{
                rs.close();
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        if(ps != null){
            try {
                ps.close();
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
        if(connection != null){
            try {
                connection.close();
            }catch (SQLException e){
                e.printStackTrace();
            }
        }
    }
    /**
     * MVC Model 模型层  访问数据库  View 视图层 显示页面内容的  Controller 控制器 负责页面请求跳转的
     *
     * dao Data Access Object 数据访问对象
     *
     *
     */
}

9.login.jsp

<html>
<head>
    <title>登录页面</title>
    <%--引入css文件和js文件--%>
    <link rel="stylesheet" href="css/bootstrap.css">
    <script src="js/jquery.min.js"></script>
    <script src="js/bootstrap.js"></script>
    <script src="js/bootstrap.bundle.js"></script>
    <style>
        .container{
            width: 20%;
            height: 20%;
            margin-top: 10%;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="row clearfix">
        <div class="col-md-12 column">
            <form role="form" method="post" action="user?method=addUser">
                <h3 style="text-align: center">登录</h3>
                <div class="form-group">
                    <label for="exampleInputEmail1">用户名:</label><input type="text" name="username" class="form-control" id="exampleInputEmail1" />
                </div>
                <div class="form-group">
                    <label for="exampleInputPassword1">密码:</label><input type="password" name="password" class="form-control" id="exampleInputPassword1" />
                </div>
                <button type="submit" style="width: 100%" class="btn btn-info">提交</button>
            </form>
        </div>
    </div>
</div>
</body>
</html>

本文地址：https://blog.csdn.net/weixin_45820586/article/details/110219691