Spring JPA with Hibernate

Spring JPA with Hibernate

This page covers Spring JPA backed by Hibernate. Configure LocalContainerEntityManagerFactoryBean with the same DataSource used by Kaumei JDBC. Add setJpaDialect(new HibernateJpaDialect()) so Spring knows how to access the Hibernate session. With that in place DataSourceUtils.getConnection returns the transaction-bound connection. Flush the session before executing native SQL to ensure pending entity changes reach the database.

Implement a JdbcConnectionProvider that flushes the session and exposes the connection:

JpaConnectionProvider.java

public class JpaConnectionProvider implements JdbcConnectionProvider {
    private final EntityManager entityManager;
    private final DataSource dataSource;

    public JpaConnectionProvider(EntityManager entityManager, DataSource dataSource) {
        var jpaDialect = entityManager.getEntityManagerFactory() instanceof EntityManagerFactoryInfo info
                ? info.getJpaDialect()
                : null;
        if (jpaDialect == null) {
            throw new IllegalArgumentException("JPA Dialect not found");
        } else if (jpaDialect instanceof HibernateJpaDialect) {
            this.entityManager = entityManager;
            this.dataSource = requireNonNull(dataSource);
        } else {
            throw new IllegalArgumentException("Not supported JPA Dialect: " + jpaDialect.getClass().getCanonicalName());
        }
    }

    @Override
    public Connection getConnection() {
        entityManager.flush();
        return DataSourceUtils.getConnection(dataSource);
    }
}

Inject the provider into your generated classes via the Spring configuration:

SpringJpaConfig.java

@Bean
AbstractEntityManagerFactoryBean entityManagerFactory(DataSource dataSource) {
    var entityManagerFactory = new LocalContainerEntityManagerFactoryBean();
    entityManagerFactory.setJpaDialect(new HibernateJpaDialect());
    entityManagerFactory.setDataSource(dataSource);
    entityManagerFactory.setPersistenceProvider(new HibernatePersistenceProvider());
    return entityManagerFactory;
}

@Bean
PlatformTransactionManager jpaTransactionManager(
        EntityManagerFactory entityManagerFactory,
        DataSource dataSource) {
    var transactionManager = new JpaTransactionManager(entityManagerFactory);
    transactionManager.setDataSource(dataSource);
    return transactionManager;
}

@Bean
JdbcConnectionProvider jpaConnectionProvider(
        EntityManager entityManager,
        DataSource dataSource) {
    return new JpaConnectionProvider(entityManager, dataSource);
}

@Bean
TradeRepository tradeRepositoryKaumei(JdbcConnectionProvider provider) {
    return new TradeRepositoryKaumei$Jdbc(provider);
}

The example combines JPA and Kaumei JDBC in both directions inside one @Transactional service method. Its duplicate-UTI rollback verifies that the pending customer change and the Kaumei JDBC trade insert share the same Spring transaction.

References

• Spring: JPA setup

Other frameworks

This configuration has not been tested beyond Spring. Frameworks that expose a Hibernate-backed EntityManager and a transaction-bound DataSource can reuse the same pattern.