SpringBoot学习10：springboot整合mybatis

Posted 2021-02-08 天涯浪子心

需求：通过使用 SpringBoot+SpringMVC+MyBatis 整合实现一个对数据库中的 t_user 表的 CRUD 的操作

1、创建maven项目，添加项目所需依赖

<!--springboot项目依赖的父项目-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
    </parent>

    <dependencies>
        <!--注入springboot启动器-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--注入springboot对thymeleaf视图技术的支持-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!--mybaits启动器，注入springboot对mybatis的支持-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!-- mysql 数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- 阿里巴巴druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.9</version>
        </dependency>
        <!-- jpa实体类规范 -->
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>persistence-api</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>

2、在resource文件夹下添加application.properties全局配置文件

#数据库连接信息
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/springboot
spring.datasource.username=root
spring.datasource.password=duan
#数据库连接池
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
#配置mybatis中实体类xml配置文件中实体类所在文件夹，如果配置了，在xml配置文件中参数、返回值实体类可以不写包名
mybatis.type-aliases-package=com.bjsxt.pojo
#mapper接口xml文件所在位置
mybatis.mapper-locations=classpath:mapping/*.xml

3、数据库设计

创建数据库

DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user` (
  `id` bigint(10) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `age` smallint(3) DEFAULT NULL,
  `hobby` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;

添加数据

INSERT INTO `t_user` VALUES (\'1\', \'张三\', \'22\', \'羽毛球\');
INSERT INTO `t_user` VALUES (\'2\', \'李四\', \'20\', \'篮球\');
INSERT INTO `t_user` VALUES (\'3\', \'王五\', \'24\', \'排球\');

4、创建实体类User

package com.bjsxt.pojo;

import javax.persistence.*;

/**
 * Created by Administrator on 2019/2/10.
 */
@Entity
@Table(name = "t_user")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Column(name = "name")
    private String name;

    @Column(name = "age")
    private int age;

    @Column(name = "hobby")
    private String hobby;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getHobby() {
        return hobby;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }
}

5、创建mapper接口以及接口映射的配置文件

package com.bjsxt.mapper;

import com.bjsxt.pojo.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

/**
 * Created by Administrator on 2019/2/10.
 */
public interface UserMapper {

    /**
     * 查询所有的用户
     * @return
     */
    List<User> selectAllUser();

    /**
     * 查询单个用户
     */
    User selectUserById(Integer id);

    /**
     * 添加用户
     */
    void addUser(User user);

    /**
     * 修改用户
     */
    void updateUser(User user);

    /**
     * 删除用户
     */
    void deleteUser(Integer id);

}

<?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 namespace="com.bjsxt.mapper.UserMapper">
    <select id="selectAllUser" resultType="User">
        select * from t_user;
    </select>

    <select id="selectUserById" parameterType="java.lang.Integer" resultType="User">
        select * from t_user where id=#{id};
    </select>

    <insert id="addUser" parameterType="User">
        insert into t_user(name,age,hobby) values(#{name},#{age},#{hobby});
    </insert>

    <update id="updateUser" parameterType="User">
        update t_user set name=#{name},age=#{age},hobby=#{hobby} where id=#{id};
    </update>

    <delete id="deleteUser" parameterType="java.lang.Integer">
        delete from t_user where id=#{id};
    </delete>
</mapper>

6、创建业务层

接口：

package com.bjsxt.service;

import com.bjsxt.pojo.User;

import java.util.List;

/**
 * Created by Administrator on 2019/2/10.
 */
public interface UserService {

    /**
     * 查询所有的用户
     * @return
     */
    List<User> selectAllUser();

    /**
     * 查询单个用户
     */
    User selectUserById(Integer id);

    /**
     * 添加用户
     */
    void addUser(User user);

    /**
     * 修改用户
     */
    void updateUser(User user);

    /**
     * 删除用户
     */
    void deleteUser(Integer id);

}

实现类

package com.bjsxt.service.impl;

        import com.bjsxt.mapper.UserMapper;
        import com.bjsxt.pojo.User;
        import com.bjsxt.service.UserService;
        import org.springframework.beans.factory.annotation.Autowired;
        import org.springframework.stereotype.Service;
        import org.springframework.transaction.annotation.Transactional;

        import java.util.List;

/**
 * Created by Administrator on 2019/2/10.
 */
@Service
@Transactional //service层打开事务
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> selectAllUser() {
        return userMapper.selectAllUser();
    }

    @Override
    public User selectUserById(Integer id) {
        return userMapper.selectUserById(id);
    }

    @Override
    public void addUser(User user) {
        userMapper.addUser(user);
    }

    @Override
    public void updateUser(User user) {
        userMapper.updateUser(user);
    }

    @Override
    public void deleteUser(Integer id) {
        userMapper.deleteUser(id);
    }
}

7、创建controller

package com.bjsxt.controller;

import com.bjsxt.pojo.User;
import com.bjsxt.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.http.HttpServletRequest;

/**
 * Created by Administrator on 2019/2/10.
 */
@Controller
@RequestMapping("user")
public class UserController {

    @Autowired
    private UserService userService;

    /**
     * 去用户列表页面
     * @param model
     * @return
     */
    @RequestMapping("toUserList")
    public String toUserList(Model model){
        model.addAttribute("userList",userService.selectAllUser());
        return "user_list";
    }

    /**
     * 去用户编辑添加页面
     */
    @RequestMapping("toUserEdit")
    public String toUserEdit(HttpServletRequest request,Model model){
        String id=request.getParameter("id");
        if(null!=id&&!"".equals(id)){   //编辑
            User user=userService.selectUserById(Integer.parseInt(id));
            model.addAttribute("user",user);
        }
        return "user_edit";
    }
    /**
     * 用户添加或编辑
     */
    @RequestMapping(value = "userEdit",method = RequestMethod.POST)
    public String userEdit(HttpServletRequest request,User user){
        if(null!=user.getId()&&!"".equals(user.getId())){   //编辑
            userService.updateUser(user);
        }else{  //添加
            userService.addUser(user);
        }
        return "redirect:/user/toUserList";
    }

    /**
     * 用户删除
     */
    @RequestMapping("deleteUser")
    public String deleteUser(Integer id){
        userService.deleteUser(id);
        return "redirect:/user/toUserList";
    }

}

8、编写页面，视图层采用thymeleaf技术

用户列表页面user_list.html

<!DOCTYPE html >
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>用户列表</title>
</head>
<body>
    <div>
        <div><a href="toUserEdit">添加</a></div>
        <table>
            <tr>
                <th>用户id</th>
                <th>用户姓名</th>
                <th>用户年龄</th>
                <th>用户爱好</th>
                <th>操作</th>
            </tr>
            <tr th:each="user:${userList}">
                <td th:text="${user.id}"></td>
                <td th:text="${user.name}"></td>
                <td th:text="${user.age}"></td>
                <td th:text="${user.hobby}"></td>
                <td>
                    <a th:href="@{/user/toUserEdit(id=${user.id})}">编辑</a>
                    <a th:href="@{/user/deleteUser(id=${user.id})}">删除</a>
                </td>
            </tr>
        </table>
    </div>
</body>
</html>

用户添加编辑页面user_edit.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>用户编辑添加</title>
</head>
<body>
    <form action="/user/userEdit" method="post">
        <input type="hidden" name="id" th:field="${user.id}">
        用户姓名：<input type="text" name="name" th:field="${user.name}"><br />
        用户年龄：<input type="text" name="age" th:field="${user.age}"><br />
        用户爱好：<input type="text" name="hobby" th:field="${user.hobby}"><br />
        <input type="submit" value="提交">
    </form>
</body>
</html>

9、编写启动类

package com.bjsxt;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * Created by Administrator on 2019/2/10.
 */
@SpringBootApplication
@MapperScan("com.bjsxt.mapper") //指定mapper接口所在的位置
public class App {

    public static void main(String[] args){
        SpringApplication.run(App.class,args);
    }
}

在浏览器中访问即可http://localhost:8080/user/toUserList

 10、最后目录结构