MyBatis入门项目案例

最新推荐文章于 2023-12-01 19:25:02 发布

joker柒月

最新推荐文章于 2023-12-01 19:25:02 发布

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分类专栏： Mybatis

本文链接：https://blog.youkuaiyun.com/qwl755/article/details/106048910

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这篇博客详细介绍了MyBatis的入门使用，包括项目效果演示、数据表创建、界面准备、主配置解析、SqlSessionFactoryUtils的使用、监听器配置、查询、添加、修改和删除用户数据的操作。此外，还涉及到了多表关联操作，展示了如何处理一个用户有多个地址的情况。

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项目效果演示

后台管理系统用户数据维护平台

创建数据表

create database mydb;
use mydb;

create table users(
	id int auto_increment primary key comment '用户编号',
	username varchar(50) not null comment '登录账号',
	userpass varchar(50) not null comment '登录密码',
	nickname varchar(50) comment '昵称',
	age int comment '用户年龄',
	gender varchar(5) comment '用户性别',
	phone varchar(13) comment '联系方式',
	email varchar(20) comment '用户邮箱',
	createTime DATETIME comment '账号创建时间',
	updateTime DATETIME comment '账号最后一次登录时间',
	userStatus int comment '用户账号状态 0 正常 1 锁定 2 删除',
	remark Text comment '备注'
);

界面准备工作

HTML+CSS+Bootstrap

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<html>
<head>
    <title>慕课网用户管理中心</title>
    <link rel="stylesheet" href="lib/bootstrap-3.3.7-dist/css/bootstrap.min.css">
    <script src="lib/2.2.4/jquery-1.12.4.min.js"></script>
    <script src="lib/bootstrap-3.3.7-dist/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="page-header">
            <h1>慕课网后台管理系统 <small>用户数据管理中心</small></h1>
        </div>
    </div>
    <div class="row">
        <div class="jumbotron">
            <h1>MyBatis基础入门课程!</h1>
            <p>通过一个项目来完成基础部分的学习</p>
            <p><a class="btn btn-primary btn-lg" href="#" role="button">查看更多，请上慕课网</a></p>
            <p><a class="btn btn-primary btn-lg" href="${pageContext.request.contextPath}/addusers.jsp" role="button">新增用户</a></p>
        </div>
    </div>
    <div class="row">
        <table class="table table-hover table-striped">
            <tr>
                <th>用户编号</th>
                <th>登录账号</th>
                <th>用户昵称</th>
                <th>邮箱</th>
                <th>联系方式</th>
                <th>账号创建时间</th>
                <th>用户状态</th>
                <th>操作</th>
            </tr>
            <tr>
                <td>1</td>
                <td>2</td>
                <td>3</td>
                <td>4</td>
                <td>5</td>
                <td>6</td>
                <td>7</td>
                <td>
                    <a href="">查看</a>
                    <a href="">锁定</a>
                    <a href="">解锁</a>
                </td>
            </tr>
        </table>
</body>
</html>

基础操作--主配置解析

pem.xml

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!--
    properties配置，用于加载外部的properties配置文件
    -->
    <properties resource="db.properties"></properties>



    <!--
    environments 主要用于进行数据源的配置
    可以配置多个数据源~ 通过default属性来指定当前项目运行过程中使用的是哪个数据源
    -->
    <environments default="development">
        <!--
        environment 用于配置一个具体的独立的数据源
        id属性用于给当前数据源定义一个名称，方便我们的项目指定
        -->
        <environment id="development">
            <!--
            transactionManager用于配置事务管理，默认情况下使用的是JDBC事务管理
            -->
            <transactionManager type="JDBC"/>
            <!--
            dataSource具体数据源的链接信息；type属性用于指定是否使用连接池
            -->
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
        <environment id="product">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
        <environment id="test">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    <!-- mappers主要用于配置我们外部的映射配置文件
        在主配置文件中需要引入加载映射配置文件
     -->
    <mappers>
        <!-- mapper主要配置引入某一个具体的映射文件，resource进行路径方式的引入 -->
        <mapper resource="mapper/usersMapper.xml"/>
    </mappers>
</configuration>

dao/Users

package com.damu.entity;

import java.util.Date;
import java.util.List;

public class Users {

    private Integer id;                 // 用户编号
    // private String username;            // 登录账号
    private String name;                // 登录账号
    private String userpass;            // 登录密码
    private String nickname;            // 用户昵称
    private Integer age;                // 用户年龄
    private String gender;              // 用户性别
    private String phone;               // 联系方式
    private String email;               // 用户邮箱
    private Date createTime;            // 创建时间
    private Date updateTime;            // 账号最后修改时间
    private Date lastLogin;             // 用户最后登录时间
    private Integer userStatus;         // 用户账号状态 0 正常 1 锁定 2 删除
    private String remark;              // 用户备注信息
    private List<Address> addresses;    // 用户地址信息【地址列表，有一个是默认地址】

    public Users() {
    }

    public Users(Integer id) {
        this.id = id;
    }

    public Users(String name, String userpass, String nickname, Integer age, String gender, String phone, String email) {
        this.name = name;
        this.userpass = userpass;
        this.nickname = nickname;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
        this.email = email;
    }

    public Users(Integer id, String nickname, Integer age, String gender, String phone, String email, Date updateTime, String remark) {
        this.id = id;
        this.nickname = nickname;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
        this.email = email;
        this.updateTime = updateTime;
        this.remark = remark;
    }

    public Users(String name, String userpass, String nickname, Integer age, String gender, String phone, String email, Date createTime, Date updateTime, Date lastLogin, Integer userStatus) {
        this.name = name;
        this.userpass = userpass;
        this.nickname = nickname;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
        this.email = email;
        this.createTime = createTime;
        this.updateTime = updateTime;
        this.lastLogin = lastLogin;
        this.userStatus = userStatus;
    }

    public Users(Integer id, String nickname, Integer age, String gender, String phone, String email, String remark) {
        this.id = id;
        this.nickname = nickname;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
        this.email = email;
        this.remark = remark;
    }

    //get和set

    @Override
    public String toString() {
        return "Users{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", userpass='" + userpass + '\'' +
                ", nickname='" + nickname + '\'' +
                ", age=" + age +
                ", gender='" + gender + '\'' +
                ", phone='" + phone + '\'' +
                ", email='" + email + '\'' +
                ", createTime=" + createTime +
                ", updateTime=" + updateTime +
                ", lastLogin=" + lastLogin +
                ", userStatus=" + userStatus +
                ", remark='" + remark + '\'' +
                ", addresses=" + addresses +
                '}';
    }
}

db.properrties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=UTF-8
username=root
password=

mapper/usersMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--
mapper 用于定义一个映射配置文件的根节点
namespace属性是用来配置命名空间，主要进行session级别的缓存管理
命名空间默认情况下，使用我们当前操作的实体类的全路径
-->
<mapper namespace="com.damu.entity.Users">

    <!--<select id="findUsers" resultType="com.damu.entity.Users">-->
    <select id="findUsers" resultMap="forUsers">
        select * from users

        <if test="id != null">
            where id = #{id}
        </if>
    </select>

    <!-- 自定义映射关系集合：主要包含对于一些自定义操作的配置，如不一致的属性和字段 -->
    <resultMap id="forUsers" type="com.damu.entity.Users">
        <!-- 绑定id主键 -->
        <id property="id" column="id"></id>
        <!-- result配置，主要配置普通属性，column表示配置的是数据库字段名称 property配置的是实体类的属性名称 -->
        <result column="username" property="name"></result>

        <collection property="addresses" column="id" ofType="com.damu.entity.Address" select="getAddress"></collection>
    </resultMap>

    <select id="getAddress" resultType="com.damu.entity.Address">
        select * from address where userid = #{id}
    </select>



    <sql id="user_fields">
        username, userpass, nickname, age, gender, email, phone, createTime, updateTime, lastLogin, userstatus, remark
    </sql>

    <insert id="addUser" useGeneratedKeys="true" keyProperty="id">
        insert into users( <include refid="user_fields"></include>)
        values(#{name},#{userpass}, #{nickname}, #{age}, #{gender}, #{email}, #{phone}, #{createTime}, #{updateTime}, #{lastLogin}, #{userStatus}, #{remark})
    </insert>

    <update id="updateUser">
        update users
        <set>
            <if test="name != null">username = #{name},</if>
            <if test="userpass != null">userpass = #{userpass},</if>
            <if test="nickname != null">nickname = #{nickname},</if>
            <if test="age != null">age = #{age},</if>
            <if test="gender != null">gender = #{gender},</if>
            <if test="email != null">email = #{email},</if>
            <if test="phone != null">phone = #{phone},</if>
            <if test="createTime != null">createTime = #{createTime},</if>
            <if test="updateTime != null">updateTime = #{updateTime},</if>
            <if test="lastLogin != null">lastlogin = #{lastLogin},</if>
            <if test="userStatus != null">userStatus = #{userStatus},</if>
            <if test="remark != null">remark = #{remark},</if>
        </set>
          where id = #{id}
    </update>

    <delete id="delUser">
        delete from users where id = #{id}
    </delete>
</mapper>

utils/SqlSessionFactoryUtils

package com.damu.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

/**
 * Created by mouwe on 2017/5/23.
 */
public class SqlSessionFactoryUtils {

    private static String RESOURCE = "mybatis-config.xml";

    private static SqlSessionFactory sqlSessionFactory;

    private static ThreadLocal<SqlSession> threadLocal = new ThreadLocal<SqlSession>();

    /**
     * 创建一个初始化SqlSessionFactory的方法
     */
    public static void initSqlSessionFactry() {
        try {
            InputStream is = Resources.getResourceAsStream(RESOURCE);

            sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取工厂对象的方法
     * @return
     */
    public static SqlSessionFactory getSqlSessionFactory() {
        return sqlSessionFactory;
    }

    /**
     * 关闭SqlSession的方法
     */
    public static void close(){
        SqlSession session = threadLocal.get();
        if(session != null) {
            session.close();
            threadLocal.set(null);
        }
    }
}

listener/InitSqlSessionListener

package com.damu.listener;

import com.damu.utils.SqlSessionFactoryUtils;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

@WebListener
public class InitSqlSessionListener implements ServletContextListener {
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        System.out.println("容器加载中...");
        // 初始化我们的SqlSesionFactory对象
        SqlSessionFactoryUtils.initSqlSessionFactry();
    }

    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        System.out.println("容器销毁中...");
        // 关闭SqlSession对象
        SqlSessionFactoryUtils.close();
    }
}

dao/UserDAO

package com.damu.dao;

import com.damu.entity.Users;
import com.damu.utils.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import java.util.List;


public class UsersDAO {
    private SqlSession sqlSession;
    private List<Users> list;
    private Users user;

    private SqlSession getSession() {
        sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
        return sqlSession;
    }

    /**
     * 查询全部用户
     * @return
     */
    public List<Users> findAll() {
        try {
            list = getSession().selectList("findUsers");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            sqlSession.close();
        }
        return list;
    }

}

servlet/UsersFindServlet

package com.damu.servlet;

import com.damu.dao.UsersDAO;
import com.damu.entity.Users;

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.util.List;


@WebServlet("/index")
public class UsersFindServlet extends HttpServlet {

    private UsersDAO usersDAO = new UsersDAO();

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

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("sssss");
        List<Users> list = usersDAO.findAll();
        System.out.println(list);
        req.setAttribute("usersList", list);

        req.getRequestDispatcher("index.jsp").forward(req, resp);
    }
}

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<html>
<head>
    <title>慕课网用户管理中心</title>
    <link rel="stylesheet" href="lib/bootstrap-3.3.7-dist/css/bootstrap.min.css">
    <script src="lib/2.2.4/jquery-1.12.4.min.js"></script>
    <script src="lib/bootstrap-3.3.7-dist/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="page-header">
            <h1>慕课网后台管理系统 <small>用户数据管理中心</small></h1>
        </div>
    </div>
    <div class="row">
        <div class="jumbotron">
            <h1>MyBatis基础入门课程!</h1>
            <p>通过一个项目来完成基础部分的学习</p>
            <p><a class="btn btn-primary btn-lg" href="#" role="button">查看更多，请上慕课网</a></p>
            <p><a class="btn btn-primary btn-lg" href="${pageContext.request.contextPath}/addusers.jsp" role="button">新增用户</a></p>
        </div>
    </div>
    <div class="row">
        <table class="table table-hover table-striped">
            <tr>
                <th>用户编号</th>
                <th>登录账号</th>
                <th>用户昵称</th>
                <th>邮箱</th>
                <th>联系方式</th>
                <th>账号创建时间</th>
                <th>用户状态</th>
                <th>操作</th>
            </tr>
            <c:forEach var="user" items="${usersList}">
            <tr>
                <td>${user.id}</td>
                <%--<td>${user.username}</td>--%>
                <td>${user.name}</td>
                <td>${user.nickname}</td>
                <td>${user.email}</td>
                <td>${user.phone}</td>
                <td>
                    <fmt:formatDate value="${user.createTime}" pattern="yyyy-MM-dd HH:mm:ss"></fmt:formatDate>
                </td>
                <c:if test="${user.userStatus == 0}">
                    <td>正常</td>
                </c:if>
                <c:if test="${user.userStatus == 1}">
                    <td>锁定</td>
                </c:if>
                <c:if test="${user.userStatus == 2}">
                    <td>删除</td>
                </c:if>
                <td>
                    <a href="${pageContext.request.contextPath}/detail?id=${user.id}">查看</a>
                    <c:if test="${user.userStatus == 0}">
                        <a href="${pageContext.request.contextPath}/deluser?id=${user.id}&type=lock">锁定</a>
                    </c:if>
                    <c:if test="${user.userStatus == 1}">
                        <a href="${pageContext.request.contextPath}/deluser?id=${user.id}&type=unlock">解锁</a>
                    </c:if>
                    <a href="${pageContext.request.contextPath}/deluser?id=${user.id}&type=del">删除</a>
                </td>
            </tr>
            </c:forEach>
        </table>
    </div>
</div>
</body>
</html>

home.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%
    response.sendRedirect("index");
%>
</body>
</html>

查询单个用户

UsersDAO

/**
     * 查询单个用户根据编号
     * @return
     */
    public Users findById(Integer id) {
        try {
            user = getSession().selectOne("findUsers", new Users(id));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            sqlSession.close();
        }
        return user;
    }

servlet/UsersFindByIdServlet

package com.damu.servlet;

import com.damu.dao.UsersDAO;
import com.damu.entity.Users;
import org.apache.log4j.Logger;

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;

@WebServlet("/detail")
public class UsersFindByIdServlet extends HttpServlet {

    private UsersDAO usersDAO = new UsersDAO();

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

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String id = req.getParameter("id");

        Users user = usersDAO.findById(Integer.parseInt(id));

        req.setAttribute("user", user);

        req.getRequestDispatcher("detail.jsp").forward(req, resp);
    }
}

detail.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<html>
<head>
    <title>慕课网用户管理中心</title>
    <link rel="stylesheet" href="lib/bootstrap-3.3.7-dist/css/bootstrap.min.css">
    <script src="lib/2.2.4/jquery-1.12.4.min.js"></script>
    <script src="lib/bootstrap-3.3.7-dist/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="page-header">
            <h1>慕课网后台管理系统 <small>用户数据管理中心</small></h1>
        </div>
    </div>
    <div class="row">
        <div class="jumbotron">
            <h1>MyBatis基础入门课程!</h1>
            <p>通过一个项目来完成基础部分的学习</p>
            <p><a class="btn btn-primary btn-lg" href="#" role="button">查看更多，请上慕课网</a></p>
        </div>
    </div>
    <c:set var="user" value="${user}"></c:set>
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <form class="form-horizontal" action="${pageContext.request.contextPath}/updateusers">
                <input type="hidden" name="id" value="${user.id}">
                <div class="form-group">
                    <label class="col-sm-2 control-label">用户账号</label>
                    <div class="col-sm-10">
                        <%--<p class="form-control-static">${user.username}</p>--%>
                            <p class="form-control-static">${user.name}</p>
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-2 control-label">登录密码</label>
                    <div class="col-sm-10">
                        <p class="form-control-static">********</p>
                    </div>
                </div>
                <div class="form-group">
                    <label for="nickname" class="col-sm-2 control-label">昵称</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="nickname" value="${user.nickname}" name="nickname" placeholder="请输入昵称">
                    </div>
                </div>
                <div class="form-group">
                    <label for="age" class="col-sm-2 control-label">年龄</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="age" name="age" value="${user.age}" placeholder="请输入年龄">
                    </div>
                </div>
                <div class="form-group">
                    <label for="gender" class="col-sm-2 control-label">性别</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="gender" name="gender" value="${user.gender}" placeholder="请输入性别">
                    </div>
                </div>
                <div class="form-group">
                    <label for="phone" class="col-sm-2 control-label">联系方式</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="phone" name="phone" value="${user.phone}" placeholder="请输入联系方式">
                    </div>
                </div>
                <div class="form-group">
                    <label for="email" class="col-sm-2 control-label">邮箱</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="email" name="email" value="${user.email}" placeholder="请输入邮箱">
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-2 control-label">账号创建时间</label>
                    <div class="col-sm-10">
                        <p class="form-control-static">
                            <fmt:formatDate value="${user.createTime}" pattern="yyyy-MM-dd"></fmt:formatDate>
                        </p>
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-2 control-label">最后修改时间</label>
                    <div class="col-sm-10">
                        <p class="form-control-static">
                            <fmt:formatDate value="${user.updateTime}" pattern="yyyy-MM-dd"></fmt:formatDate>
                        </p>
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-2 control-label">最后登录时间</label>
                    <div class="col-sm-10">
                        <p class="form-control-static">
                            <fmt:formatDate value="${user.lastLogin}" pattern="yyyy-MM-dd"></fmt:formatDate>
                        </p>
                    </div>
                </div>
                <div class="form-group">
                    <label class="col-sm-2 control-label">用户状态</label>
                    <div class="col-sm-10">
                        <c:if test="${user.userStatus == 0}">
                            <p class="form-control-static">正常</p>
                        </c:if>
                        <c:if test="${user.userStatus == 1}">
                            <p class="form-control-static">锁定</p>
                        </c:if>
                        <c:if test="${user.userStatus == 2}">
                            <p class="form-control-static">删除</p>
                        </c:if>
                    </div>
                </div>
                <div class="form-group">
                    <label for="remark" class="col-sm-2 control-label">备注</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="remark" value="${user.remark}" name="remark" placeholder="请输入备注">
                    </div>
                </div>
                <div class="form-group">
                    <input type="submit" value="提交数据更新" class="btn btn-primary">
                </div>
            </form>
        </div>
    </div>
    <div class="row">
        <table class="table table-striped">
            <tr>
                <th>地址编号</th>
                <th>国家</th>
                <th>省</th>
                <th>市</th>
                <th>县</th>
                <th>街道</th>
                <th>详细地址</th>
                <th>是否默认</th>
            </tr>
            <c:forEach var="addr" items="${user.addresses}">
                <tr>
                    <td>${addr.id}</td>
                    <td>${addr.nation}</td>
                    <td>${addr.province}</td>
                    <td>${addr.city}</td>
                    <td>${addr.country}</td>
                    <td>${addr.street}</td>
                    <td>${addr.remark}</td>
                    <c:if test="${addr.defaultAddr == true}">
                        <td>默认地址</td>
                    </c:if>
                    <c:if test="${addr.defaultAddr == false}">
                        <td>-----</td>
                    </c:if>
                </tr>
            </c:forEach>
        </table>
    </div>
</div>

</body>
</html>

基础操作--查询数据

映射配置：sql片段

映射配置select配置

特殊配置：字段和属性不一致时resultMap配置

数据库中字段为username 实体类中为user

    <!--<select id="findUsers" resultType="com.damu.entity.Users">-->
    <select id="findUsers" resultMap="forUsers">
        select * from users

        <if test="id != null">
            where id = #{id}
        </if>
    </select>
    
<!-- 自定义映射关系集合：主要包含对于一些自定义操作的配置，如不一致的属性和字段 -->
    <resultMap id="forUsers" type="com.damu.entity.Users">
        <!-- 绑定id主键 -->
        <id property="id" column="id"></id>
        <!-- result配置，主要配置普通属性，column表示配置的是数据库字段名称 property配置的是实体类的属性名称 -->
        <result column="username" property="name"></result>
    </resultMap>

添加log4j

log4j.properties

log4j.rootLogger=DEBUG, A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r %-5p [%t] %37c %3x - %m%n

UsersFindByIdServlet

package com.damu.servlet;

import com.damu.dao.UsersDAO;
import com.damu.entity.Users;
import org.apache.log4j.Logger;

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;

@WebServlet("/detail")
public class UsersFindByIdServlet extends HttpServlet {

    /*
    创建对应的日志记录对象
    通过不同的级别进行日志的记录【DEBUG\WARN\INFO]
     */
    private Logger log = Logger.getLogger(UsersFindByIdServlet.class);


    private UsersDAO usersDAO = new UsersDAO();

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

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String id = req.getParameter("id");

        log.info("获取到查询参数id--》" + id);

        Users user = usersDAO.findById(Integer.parseInt(id));

        log.info("查询数完成，查询到的数据：" + user);

        req.setAttribute("user", user);

        req.getRequestDispatcher("detail.jsp").forward(req, resp);
    }
}

基础操作---增加数据

usersMapper.xml

    <sql id="user_fields">
        username, userpass, nickname, age, gender, email, phone, createTime, updateTime, lastLogin, userstatus, remark
    </sql>   
    <insert id="addUser" useGeneratedKeys="true" keyProperty="id">
        insert into users( <include refid="user_fields"></include>)
        values(#{name},#{userpass}, #{nickname}, #{age}, #{gender}, #{email}, #{phone}, #{createTime}, #{updateTime}, #{lastLogin}, #{userStatus}, #{remark})
    </insert>

UsersDAO

/**
     * 增加一个新用户数据到数据库的方法
     * @return
     */
    public Users addUser(Users user) {
        try {

            // 返回值：是insert执行过程中影响的行数
            getSession().insert("addUser", user);

            sqlSession.commit();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            sqlSession.close();
        }
        return user;
    }

UsersAddServlet

package com.damu.servlet;

import com.damu.dao.UsersDAO;
import com.damu.entity.Users;

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.util.Date;

@WebServlet("/addusers")
public class UsersAddServlet extends HttpServlet {

    private UsersDAO usersDAO = new UsersDAO();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取要添加的用户数据
        String username = req.getParameter("username");
        String userpass = req.getParameter("userpass");
        String nickname = req.getParameter("nickname");
        String age = req.getParameter("age");
        String gender = req.getParameter("gender");
        String email = req.getParameter("email");
        String phone = req.getParameter("phone");

        // 根据用户数据创建一个用户对象
        Users user = new Users(username, userpass, nickname, Integer.parseInt(age), gender, email, phone, new Date(), new Date(), new Date(), 0);

        // 将用户对象添加到数据库中
        user = usersDAO.addUser(user);

        // 查看刚新增的用户数据
        resp.sendRedirect(req.getContextPath()"/detail?id=" + user.getId());
    }
}

addusers.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<html>
<head>
    <title>慕课网用户管理中心</title>
    <link rel="stylesheet" href="lib/bootstrap-3.3.7-dist/css/bootstrap.min.css">
    <script src="lib/2.2.4/jquery-1.12.4.min.js"></script>
    <script src="lib/bootstrap-3.3.7-dist/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
    <div class="row">
        <div class="page-header">
            <h1>慕课网后台管理系统 <small>用户数据管理中心</small></h1>
        </div>
    </div>
    <div class="row">
        <div class="jumbotron">
            <h1>MyBatis基础入门课程!</h1>
            <p>通过一个项目来完成基础部分的学习</p>
            <p><a class="btn btn-primary btn-lg" href="#" role="button">查看更多，请上慕课网</a></p>
        </div>
    </div>
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <form class="form-horizontal" action="${pageContext.request.contextPath}/addusers">
                <div class="form-group">
                    <label for="username" class="col-sm-2 control-label">用户账号</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="username" name="username" placeholder="请输入用户账号">
                    </div>
                </div>
                <div class="form-group">
                    <label for="userpass" class="col-sm-2 control-label">登录密码</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="userpass" name="userpass" placeholder="请输入登录密码">
                    </div>
                </div>
                <div class="form-group">
                    <label for="nickname" class="col-sm-2 control-label">昵称</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="nickname" name="nickname" placeholder="请输入昵称">
                    </div>
                </div>
                <div class="form-group">
                    <label for="age" class="col-sm-2 control-label">年龄</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="age" name="age"  placeholder="请输入年龄">
                    </div>
                </div>
                <div class="form-group">
                    <label for="gender" class="col-sm-2 control-label">性别</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="gender" name="gender"  placeholder="请输入性别">
                    </div>
                </div>
                <div class="form-group">
                    <label for="phone" class="col-sm-2 control-label">联系方式</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="phone" name="phone"  placeholder="请输入联系方式">
                    </div>
                </div>
                <div class="form-group">
                    <label for="email" class="col-sm-2 control-label">邮箱</label>
                    <div class="col-sm-10">
                        <input type="text" class="form-control" id="email" name="email" placeholder="请输入邮箱">
                    </div>
                </div>
                <div class="form-group">
                    <input type="submit" value="点击新增用户" class="btn btn-primary">
                </div>
            </form>
        </div>
    </div>
</div>

</body>
</html>

基础操作---修改数据

usersMapper.xml

<update id="updateUser">
        update users
        <set>
            <if test="name != null">username = #{name},</if>
            <if test="userpass != null">userpass = #{userpass},</if>
            <if test="nickname != null">nickname = #{nickname},</if>
            <if test="age != null">age = #{age},</if>
            <if test="gender != null">gender = #{gender},</if>
            <if test="email != null">email = #{email},</if>
            <if test="phone != null">phone = #{phone},</if>
            <if test="createTime != null">createTime = #{createTime},</if>
            <if test="updateTime != null">updateTime = #{updateTime},</if>
            <if test="lastLogin != null">lastlogin = #{lastLogin},</if>
            <if test="userStatus != null">userStatus = #{userStatus},</if>
            <if test="remark != null">remark = #{remark},</if>
        </set>
          where id = #{id}
    </update>

UsersDAO

    /**
     * 用于修改用户资料的方法
     * @return
     */
    public void delUsers(Integer id) {
        try {

            // 返回值：是insert执行过程中影响的行数
            getSession().delete("delUser", id);

            sqlSession.commit();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            sqlSession.close();
        }
    }

UserUpdateServlet

package com.damu.servlet;

import com.damu.dao.UsersDAO;
import com.damu.entity.Users;

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.util.Date;

@WebServlet("/updateusers")
public class UsersUpdateServlet extends HttpServlet {

    private UsersDAO usersDAO = new UsersDAO();

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

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取用户要更新的数据
        String id = req.getParameter("id");
        String nickname = req.getParameter("nickname");
        String age = req.getParameter("age");
        String gender = req.getParameter("gender");
        String email = req.getParameter("email");
        String phone = req.getParameter("phone");
        String remark = req.getParameter("remark");

        // 创建用户对象
        Users user = new Users(Integer.parseInt(id), nickname, Integer.parseInt(age), gender, email, phone, new Date(),remark);

        // 提交更新
        usersDAO.updateUsers(user);

        // 查看更新后的用户数据
        resp.sendRedirect("/detail?id=" + user.getId());
    }
}

基础操作---删除操作

usersMapper.xml

    <delete id="delUser">
        delete from users where id = #{id}
    </delete>

UsersDAO

    public void delUsers(Integer id) {
        try {

            // 返回值：是insert执行过程中影响的行数
            getSession().delete("delUser", id);

            sqlSession.commit();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            sqlSession.close();
        }
    }

UersDelServlet

package com.damu.servlet;

import com.damu.dao.UsersDAO;
import com.damu.entity.Users;

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;

@WebServlet("/deluser")
public class UsersDelServlet extends HttpServlet {

    private UsersDAO usersDAO = new UsersDAO();

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

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 获取参数
        String id = req.getParameter("id");
        String type = req.getParameter("type");

        // 执行删除或者锁定
        if ("lock".equals(type)) {
            // 执行锁定操作：update操作
            Users user = new Users();
            user.setId(Integer.parseInt(id));
            user.setUserStatus(1);

            usersDAO.updateUsers(user);

        } else if ("del".equals(type)) {
            // 执行的删除操作：delete操作
            usersDAO.delUsers(Integer.parseInt(id));
        } else if("unlock".equals(type)) {
            // 执行解锁操作：update操作
            Users user = new Users();
            user.setId(Integer.parseInt(id));
            user.setUserStatus(0);

            usersDAO.updateUsers(user);
        }

        // 跳转到首页
        resp.sendRedirect("/index");
    }
}

多表关联操作

一个用户有多个地址

在用户中加入字段address

usersMapper.xml

    <!-- 自定义映射关系集合：主要包含对于一些自定义操作的配置，如不一致的属性和字段 -->
    <resultMap id="forUsers" type="com.damu.entity.Users">
        <!-- 绑定id主键 -->
        <id property="id" column="id"></id>
        <!-- result配置，主要配置普通属性，column表示配置的是数据库字段名称 property配置的是实体类的属性名称 -->
        <result column="username" property="name"></result>

        <collection property="addresses" column="id" ofType="com.damu.entity.Address" select="getAddress"></collection>
    </resultMap>

    <select id="getAddress" resultType="com.damu.entity.Address">
        select * from address where userid = #{id}
    </select>