Hibernate propose :

• Schéma dynamique mais unique pour toutes les entités
• Schéma figé mais différent selon entités

1) Rajouter un Interceptor Hibernate :

/**
 * This class can rebuild requests.
 */
@Component
public class HibernateSchemaInterceptor extends EmptyInterceptor {

    public final static Logger LOGGER = LoggerFactory.getLogger(HibernateSchemaInterceptor.class.getCanonicalName());

    public HibernateSchemaInterceptor() {
        LOGGER.info("initialize HibernateSchemaInterceptor bean.");
    }

    @Override
    public String onPrepareStatement(String sql) {
        String correctedSQL = sql;
        correctedSQL = correctedSQL.replaceAll(GenericEntity.FIRST_SCHEMA_NAME, StaticServiceHolder.firstSchemaName);
        correctedSQL = correctedSQL.replaceAll(GenericEntity.SECOND_SCHEMA_NAME, StaticServiceHolder.secondSchemaName);
        return super.onPrepareStatement(correctedSQL);
    }

}

Cette classe est appelée avant ou après l'exécution d'une requête.

2) Rajouter l'interceptor aux properties JPA

    @Bean
    public Properties jpaProperties() {
        Properties props = new Properties();

        super.putProperties("hibernate.dialect", props);
        //super.putProperties("hibernate.hbm2ddl.auto", props);
        props.setProperty("hibernate.enable_lazy_load_no_trans", "true");
        props.setProperty("org.hibernate.flushMode", "AUTO");
        props.setProperty("hibernate.ejb.interceptor", HibernateSchemaInterceptor.class.getCanonicalName());

        LOGGER.info("Hibernate JPA Properties loaded");
        return props;
    }

L'instanciation serait faite via les EJB.

3) Définir un endroit ou l'interceptor pourra accéder aux beans variables (noms des schémas) :

/**
 * This class inject itself the Spring context to make it available for classes not managed by Spring.
 */
@Component
public class StaticServiceHolder {

    public static String firstSchemaName;

    public static String secondSchemaName ;

    @Autowired
    public void setFirstSchemaName(String firstSchemaName) {
        StaticServiceHolder.firstSchemaName = firstSchemaName;
    }

    @Autowired
    public void setSecondSchemaName(String secondSchemaName) {
        StaticServiceHolder. secondSchemaName =  secondSchemaName;
    }
}

4) Rajouter le nom des schémas "mocké" aux entités :

@Entity
@Table(name = "TABLE", schema = GenericEntity.FIRST_SCHEMA_NAME)
public class Entity implements GenericEntity {

//Dans les join table AUSSI :
    @JoinTable(
            name = "JT_ENTITY_ENTITY2",
            schema = GenericEntity.FIRST_SCHEMA_NAME,
            joinColumns = @JoinColumn(name = "ENTITY_ID"),
            inverseJoinColumns = @JoinColumn(name = "ENTITY2_ID")
    )
    @ManyToMany
    private Set<Entity2> linked;