springboot整合mybatis

环境说明

win10 + jdk8 + intellij2019.1 + springboot2.2.0 + mybatis-spring-boot-starter2.1.1 + MySQL5.7

准备工作

1. 在本地mysql中创建test数据库

2. 创建city表

user test;
CREATE TABLE city
(
  id      INT PRIMARY KEY auto_increment,
  name    VARCHAR(16),
  state   VARCHAR(16),
  country VARCHAR(16)
);

详细步骤

1. 创建 springboot项目，勾选所需依赖(mysql、mybatis)

2. 创建 mybatis项目结构(entity.java实体类、mapper.java接口、mapper.xml映射文件)

• 目录结构
  

• entity实体类

  package cn.juxiewl.springbootmybatis.entity;
  
  public class City {
  
      private Long id;
      private String name;
      private String state;
      private String country;
  
      public Long getId() {
          return this.id;
      }
  
      public void setId(Long id) {
          this.id = id;
      }
  
      public String getName() {
          return this.name;
      }
  
      public void setName(String name) {
          this.name = name;
      }
  
      public String getState() {
          return this.state;
      }
  
      public void setState(String state) {
          this.state = state;
      }
  
      public String getCountry() {
          return this.country;
      }
  
      public void setCountry(String country) {
          this.country = country;
      }
  
      @Override
      public String toString() {
          return getId() + "," + getName() + "," + getState() + "," + getCountry();
      }
  }
  

• mapper接口

  package cn.juxiewl.springbootmybatis.mapper;
  
  import cn.juxiewl.springbootmybatis.entity.City;
  import org.apache.ibatis.annotations.Insert;
  import org.apache.ibatis.annotations.Options;
  import org.apache.ibatis.annotations.Select;
  
  import java.util.List;
  
  /**
  * @Date 2019-10-25 18:09
  * @Version 1.0
  */
  //@Mapper
  public interface CityMapper {
  
      /**
      * 插入方法
      * @param city
      */
      @Insert("insert into city (name,state, country) values(#{name},#{state}, #{country})")
      @Options(useGeneratedKeys = true, keyProperty = "id")
      void insert(City city);
  
      @Select("select id,name,state,country FROM city WHERE id = #{id}")
      City findById(long id);
  
      /**
      * 查询所有城市信息
      * @return
      */
      List<City> selectAll();
  }
  

• mapper.xml 映射文件

  <?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="cn.juxiewl.springbootmybatis.mapper.CityMapper">
      <sql id="wrongId">
          *
      </sql>
      <select id="selectAll" resultType="cn.juxiewl.springbootmybatis.entity.City">
          SELECT
          <include refid="wrongId"/>
          FROM city
      </select>
  </mapper>
  
  

3. 配置( 4个：指定实体类、接口类、映射文件位置、数据源)

• application.yml中

  # mybatis 配置
  mybatis:
  # mapper.xml映射文件 位置
  mapper-locations: classpath:/mapper/**/*.xml
  # entity实体类包 位置
  type-aliases-package: cn.juxiewl.springbootmybatis.entity
  
  spring:
  # 数据源
  datasource:
      driver-class-name: com.mysql.cj.jdbc.NonRegisteringDriver
      url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8&useSSL=false
      username: root
      password: root
  

• springboot启动类

  package cn.juxiewl.springbootmybatis;
  
  import org.mybatis.spring.annotation.MapperScan;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  
  @SpringBootApplication
  # 指定需要扫描mapper接口的包
  @MapperScan("cn.juxiewl.springbootmybatis.mapper")
  public class SpringbootMybatisApplication {
  
      public static void main(String[] args) {
          SpringApplication.run(SpringbootMybatisApplication.class, args);
      }
  
  }
  

4. 测试

    package cn.juxiewl.springbootmybatis;

    import cn.juxiewl.springbootmybatis.entity.City;
    import cn.juxiewl.springbootmybatis.mapper.CityMapper;
    import org.junit.jupiter.api.Test;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;

    //@RunWith(SpringRunner.class)
    @SpringBootTest
    public class SpringbootMybatisApplicationTests {

        @Autowired
        private CityMapper cityMapper;

        @Test
        public void inset(){
            City city = new City();
            city.setName("xiaobailong");
            city.setCountry("EN");
            city.setState("US");
            cityMapper.insert(city);
            System.out.println("刚才插入的数据为：");
            System.out.println(cityMapper.findById(city.getId()));
        }

        @Test
        public void findAll(){
            System.out.println("-------- 查询全部数据 --------");
            System.out.println(cityMapper.selectAll());
        }

    }

参考

1. mybatis/spring-boot-starter项目

2. mybatis 在github上的所有项目