SpringBoot整合MyBatis的步骤

项目环境

开发工具：Intellij IDEA 2020.2.1
springboot：2.4.3
jdk：1.8.0_251
maven：3.6.3

第1步 导入MyBatis 整合包

<dependency>
	<groupId>org.mybatis.spring.bootgroupId>
	<artifactId>mybatis-spring-boot-starterartifactId>
	<version>2.1.1version>
dependency>

---

第2步 编写接口和xml

目录结构, 注意 mapper 包和 resources 目录下的 /mybatis/mapper 目录

第一 在 com/pro/ 目录新增 mapper 包

然后在 com/pro/mapper 包下新增 UsersMapper 接口

package com.pro.mapper;

import com.pro.pojo.Users;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
@Repository
public interface UsersMapper {
    // 查询所有用户
    List<Users> queryUserList();

    Users queryUserById(int id);
    
    int addUser(Users users);
    
    int updateUser(Users users);

    int deleteUser(int id);
}

第二 在 resources 目录下新增目录 /mybatis/mapper

然后在 resources/mybatis/mapper 目录新增 UsersMapper.xml 文件

注意 namespace 需要绑定接口

<mapper namespace="com.pro.mapper.UsersMapper">
    <select id="queryUserList" resultType="Users">
        select * from users
    select>

    <select id="queryUserById" parameterType="int" resultType="Users">
        select * from users where id = #{id}
    select>

    <insert id="addUser" parameterType="Users">
        insert into users(name, pwd) values(#{name},#{pwd})
    insert>

    <update id="updateUser" parameterType="Users">
        update users set name = #{name}, pwd = #{pwd} where id = #{id}
    update>

    <delete id="deleteUser" parameterType="int">
        delete from users where id = #{id}
    delete>
mapper>

第3步 编写配置文件 application.properties

注意 因为我把 xml 写在了 resources 目录下了, 所以这里 mybatis.mapper-locations 属性对应了这个路径 classpath:mybatis/mapper/*.xml

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

# 整合 MyBatis 配置
# 别名
mybatis.type-aliases-package=com.pro.pojo
# 绑定 mapper.xml
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

第4步 编写 controller 测试使用

在 com/pro/ 目录新增 controller 包, 编写 UsersController 类进行测试

为了方便测试, 这里就没有写 services 层了, 直接在 controller 层调用了

package com.pro.controller;

import com.pro.mapper.UsersMapper;
import com.pro.pojo.Users;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UsersController {
    @Autowired
    private UsersMapper usersMapper;

    @GetMapping("/user/list")
    public List<Users> queryUserList() {
        List<Users> users = usersMapper.queryUserList();

        return users;
    }

    @GetMapping("/user/add")
    public Object addUser() {
        Users users = new Users(null, "ControllerAddUser", "add123");

        int i = usersMapper.addUser(users);
        if (i > 0) {
            return "新增成功";
        }

        return "新增失败";
    }

    @GetMapping("/user/{id}")
    public Object deleteUser(@PathVariable("id") int id) {

        int i = usersMapper.deleteUser(id);
        if (i > 0) {
            return "删除成功";
        }

        return "删除失败";
    }
}

启动项目, 测试访问 http://localhost:8080/user/list 成功

所有依赖

<dependency>
	<groupId>org.springframework.bootgroupId>
	<artifactId>spring-boot-starter-webartifactId>
dependency>


<dependency>
	<groupId>org.mybatis.spring.bootgroupId>
	<artifactId>mybatis-spring-boot-starterartifactId>
	<version>2.1.1version>
dependency>

<dependency>
	<groupId>org.projectlombokgroupId>
	<artifactId>lombokartifactId>
dependency>


<dependency>
	<groupId>org.springframework.bootgroupId>
	<artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency>
	<groupId>mysqlgroupId>
	<artifactId>mysql-connector-javaartifactId>
	<scope>runtimescope>
dependency>