springboot整合mybatis

先创建一个springbooot项目
file->new project Spring Initalizr 勾选sql mysql Driver
这里和mybatis-plus一起整合

 <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.23</version>
    </dependency>
    <dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus-boot-starter</artifactId>
      <version>3.4.2</version>
    </dependency>
     <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.20</version>
    </dependency>
  <dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.0</version>
  </dependency>
    

yml文件

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatisplus_db?serverTimezone=UTC
    username: root
    password: root
mybatis:
  mapper-locations: com/itheima/dao/*.xml

xml文件bulid标签下加入

   <resources>
    <resource>
      <directory>src/main/java</directory>
      <includes>
        <include>**/*.xml</include>
      </includes>
      <filtering>true</filtering>
    </resource>
  </resources>

文件目录

UserDao

@Mapper
public interface UserDao extends BaseMapper<User> {
  public User findOne();
}

UserDao.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 namespace="com.itheima.dao.UserDao">

  <select id="findOne" resultType="com.itheima.domian.User" >
    select *
    from tb_user
    where id=1
  </select>
</mapper>

调用

@SpringBootTest
class MybatisplusQuickstart03ApplicationTests {
  @Autowired
  private UserDao userDao;
 @Test
  void testselect() {
    User all = userDao.findOne();
    System.out.println(all);
  }
}

如果想放到resource下只需修改pom文件 和yml中的
这里路径注意

    <resources>
    <resource>
      <directory>src/main/resources/mapper</directory>
      <includes>
        <include>*.xml</include>
      </includes>
      <filtering>true</filtering>
    </resource>
  </resources>

mybatis:
  mapper-locations: classpath:/mapper/*.xml