Multiple Datasource

Multiple Datasource

Configuration and notes

Configuration

1. application properties

  spring.datasource-first.url E.g: jdbc:postgresql://localhost:5432/first-db
  spring.datasource-first.username E.g: username
  spring.datasource-first.password E.g: password

  spring.datasource-second.url E.g:jdbc:postgresql://localhost:5433/second-db
  spring.datasource-second.username E.g: username
  spring.datasource-second.password E.g: password

2. Config Bean

   1. MultiDatasourceConfiguration

     @Configuration
     public class MultiDatasourceConfiguration {
   
     @Bean
     @ConfigurationProperties("spring.datasource-first")
     @Primary
     public DataSource firstDatasource() {
       return DataSourceBuilder.create()
           .build();
     }
   
     @Bean
     @ConfigurationProperties("spring.datasource-second")
     public DataSource secondDatasource() {
       return DataSourceBuilder.create()
           .build();
     }
   }

   2. FirstJpaConfiguration

   @Configuration
   @EnableTransactionManagement
   @EnableJpaRepositories(
       basePackages = "x1" // package contains the repository
   )
   public class FirstJpaConfiguration {
   
     @Bean
     @Primary
     public LocalContainerEntityManagerFactoryBean firstEntityManagerFactory(
         @Qualifier("firstDatasource") DataSource firstDatasource, EntityManagerFactoryBuilder builder) {
       return builder
           .dataSource(firstDatasource)
           .packages("y1") // package contains the entity
           .build();
     }
   
     @Bean
     @Primary
     public PlatformTransactionManager firstTransactionManager(
         @Qualifier("firstEntityManagerFactory") LocalContainerEntityManagerFactoryBean firstEntityManagerFactory) {
       return new JpaTransactionManager(Objects.requireNonNull(firstEntityManagerFactory.getObject()));
     }
   }

   3. SecondJpaConfiguration

   @Configuration
   @EnableTransactionManagement
   @EnableJpaRepositories(
       basePackages = "x2" // package contains the repository
   )
   public class SecondJpaConfiguration {
   
     @Bean
     public LocalContainerEntityManagerFactoryBean secondEntityManagerFactory(
         @Qualifier("secondDatasource") DataSource secondDatasource, EntityManagerFactoryBuilder builder) {
       return builder
           .dataSource(secondDatasource)
           .packages("y2") // package contains the entity
           .build();
     }
   
     @Bean
     public PlatformTransactionManager secondTransactionManager(
         @Qualifier("secondEntityManagerFactory") LocalContainerEntityManagerFactoryBean secondEntityManagerFactory) {
       return new JpaTransactionManager(Objects.requireNonNull(secondEntityManagerFactory.getObject()));
     }
   }

Notes

1. Setting for Jpa convert camelCase -> snake_case when query (setting for application properties)

    spring.jpa.properties.hibernate.implicit_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy
    spring.jpa.properties.hibernate.physical_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy

2. When use @Transactional must specify "transactionManager" (firstTransactionManager or secondTransactionManager)

3. When use EntityManager must add @PersistenceContext(unitName = "xx" xx: firstEntityManagerFactory or secondEntityManagerFactory)

4. If use liquibase then add "spring.liquibase.url" to application properties

   spring.liquibase.url //is url of datasource E.g: jdbc:postgresql://localhost:5432/first-db

Refer

https://www.baeldung.com/spring-boot-configure-multiple-datasources