详细 介绍springboot mybatis多数据源 yml配置 和mapper的方式

Spring Boot MyBatis多数据源的配置方式如下：

1. 在application.yml文件中配置多个数据源的连接信息，例如：

spring:
  datasource:
    master:
      url: jdbc:mysql://localhost:3306/master
      username: root
      password: root
    slave:
      url: jdbc:mysql://localhost:3306/slave
      username: root
      password: root

2. 在代码中定义多个数据源的Bean，例如：

@Configuration
@MapperScan(basePackages = "com.example.mapper")
public class DataSourceConfig {

    @Bean(name = "masterDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "slaveDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource slaveDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "dynamicDataSource")
    public DataSource dynamicDataSource(@Qualifier("masterDataSource") DataSource masterDataSource,
                                         @Qualifier("slaveDataSource") DataSource slaveDataSource) {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        Map<Object, Object> dataSourceMap = new HashMap<>();
        dataSourceMap.put("master", masterDataSource);
        dataSourceMap.put("slave", slaveDataSource);
        dynamicDataSource.setTargetDataSources(dataSourceMap);
        dynamicDataSource.setDefaultTargetDataSource(masterDataSource);
        return dynamicDataSource;
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dynamicDataSource") DataSource dynamicDataSource) throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dynamicDataSource);
        return sessionFactory.getObject();
    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

3. 在Mapper接口中使用@Mapper注解，并在XML文件中使用namespace指定Mapper接口的全限定名，例如：

@Mapper
public interface UserMapper {

    @Select("SELECT * FROM user WHERE id = #{id}")
    User findById(@Param("id") Long 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.example.mapper.UserMapper">
    <select id="findById" parameterType="java.lang.Long" resultType="com.example.entity.User">
        SELECT * FROM user WHERE id = #{id}
    </select>
</mapper>

这样就可以实现Spring Boot MyBatis多数据源的配置和使用了。

注意：以上代码仅供参考，具体实现方式可能会因项目需求而有所不同。