MultiTenantJpaTransactionManager.java

public class MultiTenantJpaTransactionManager extends JpaTransactionManager {

    @Inject
    private CurrentTenantResolver tenantResolver;

    @Override
    protected void doBegin(final Object transaction, final TransactionDefinition definition) {
        super.doBegin(transaction, definition);
        final EntityManagerHolder emHolder = (EntityManagerHolder) TransactionSynchronizationManager.getResource(getEntityManagerFactory());
        final EntityManager em = emHolder.getEntityManager();
        final Serializable tenantId = tenantResolver.getCurrentTenantId();
        if (tenantId != null) {
            em.setProperty("eclipselink.tenant-id", tenantId);
        } else {
            // some error handling here
        }
    }
}