[Spring Boot] Multi DataSource, MyBatis 설정하기

yml DataSource 설정

spring.datasource.primary.url=jdbc:mysql://localhost:3306/db1
spring.datasource.primary.username=user1
spring.datasource.primary.password=pass1
spring.datasource.primary.driver-class-name=com.mysql.cj.jdbc.Driver

spring.datasource.secondary.url=jdbc:mysql://localhost:3306/db2
spring.datasource.secondary.username=user2
spring.datasource.secondary.password=pass2
spring.datasource.secondary.driver-class-name=com.mysql.cj.jdbc.Driver

DataSource Bean 등록

@Configuration
@EnableTransactionManagement
public class DataSourceConfig {
    @Primary	//기본 DataSource를 지정
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource mainDataSource() {
        return DataSourceBuilder.create().build();
    }
    
    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }
}

MyBatis 설정

@Configuration
@MapperScan(
    basePackages = "com.example.mapper",
    sqlSessionFactoryRef = "sqlSessionFactory"
)
public class MyBatisConfig {

    @Bean
    public SqlSessionFactory sqlSessionFactory(
            @Qualifier("primaryDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);

        Resource[] mapperLocations = new PathMatchingResourcePatternResolver()
            .getResources("classpath:mapper/*.xml");
        sessionFactoryBean.setMapperLocations(mapperLocations);

        return sessionFactoryBean.getObject();
    }
}

Annotation을 사용하여 각각의 DataSource를 특정 Mapper 인터페이스에 적용

Annotation 생성

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Inherited
public @interface PrimaryMapper {
}

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Inherited
public @interface SecondaryMapper {
}

MapperScan에 annotationClass 적용

@Configuration
@EnableTransactionManagement
@MapperScan(basePackages = "com.example.myapp.mapper.primary", annotationClass = PrimaryMapper.class, sqlSessionTemplateRef = "primarySqlSessionTemplate")
public class PrimaryDataSourceConfig {

    @Primary
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Bean(name = "primarySqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("primaryDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/primary/*.xml"));
        return sessionFactoryBean.getObject();
    }

    @Primary
    @Bean(name = "primarySqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("primarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

@Configuration
@EnableTransactionManagement
@MapperScan(basePackages = "com.example.myapp.mapper.secondary", annotationClass = SecondaryMapper.class, sqlSessionTemplateRef = "secondarySqlSessionTemplate")
public class SecondaryDataSourceConfig {

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

    @Bean(name = "secondarySqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("secondaryDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/secondary/*.xml"));
        return sessionFactoryBean.getObject();
    }

    @Bean(name = "secondarySqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("secondarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

Mapper 인터페이스에 어노테이션을 추가

@PrimaryMapper
public interface PrimaryUserMapper {
    // ...
}

@SecondaryMapper
public interface SecondaryUserMapper {
    // ...
}