BarConfig.java

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "barEntityManagerFactory", 
        transactionManagerRef = "barTransactionManager",
        basePackages = { "com.sctrcd.multidsdemo.integration.repositories.bar" })
public class BarConfig {

    @Autowired
    JpaVendorAdapter jpaVendorAdapter;

    /**
     * Primary because if we have activated embedded databases, we do not want
     * the application to connect to an external database.
     */
    @Bean(name = "barDataSource")
    public DataSource dataSource() {
        return new EmbeddedDatabaseBuilder()
                .setName("bardb")
                .setType(EmbeddedDatabaseType.HSQL)
                .build();
    }

    @Bean(name = "barEntityManager")
    public EntityManager entityManager() {
        return entityManagerFactory().createEntityManager();
    }

    @Bean(name = "barEntityManagerFactory")
    public EntityManagerFactory entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
        lef.setDataSource(dataSource());
        lef.setJpaVendorAdapter(jpaVendorAdapter);
        lef.setPackagesToScan("com.sctrcd.multidsdemo.domain.bar");
        lef.setPersistenceUnitName("barPersistenceUnit");
        lef.afterPropertiesSet();
        return lef.getObject();
    }

    @Bean(name = "barTransactionManager")
    public PlatformTransactionManager transactionManager() {
        return new JpaTransactionManager(entityManagerFactory());
    }

}