HHH-11426 - NullPointerException in getPersistenceUnitUtil().getIdent…

…ifier() on detached enhanced entity

hibernate-entitymanager/src/main/java/org/hibernate/jpa/internal/EntityManagerFactoryImpl.java

@@ -42,6 +42,7 @@
 import org.hibernate.cache.spi.RegionFactory;
 import org.hibernate.cfg.annotations.NamedEntityGraphDefinition;
 import org.hibernate.ejb.HibernateEntityManagerFactory;
+import org.hibernate.engine.spi.EntityEntry;
 import org.hibernate.engine.spi.ManagedEntity;
 import org.hibernate.engine.spi.NamedQueryDefinition;
 import org.hibernate.engine.spi.NamedQueryDefinitionBuilder;
@@ -672,27 +673,35 @@ public Object getIdentifier(Object entity) {
 			}
 
 			if ( entity instanceof HibernateProxy ) {
-				final HibernateProxy proxy = (HibernateProxy) entity;
-				return proxy.getHibernateLazyInitializer().getIdentifier();
+				return ((HibernateProxy) entity).getHibernateLazyInitializer().getIdentifier();
 			}
 			else if ( entity instanceof ManagedEntity ) {
-				final ManagedEntity enhancedEntity = (ManagedEntity) entity;
-				return enhancedEntity.$$_hibernate_getEntityEntry().getId();
+				EntityEntry entityEntry = ((ManagedEntity) entity).$$_hibernate_getEntityEntry();
+				if ( entityEntry != null ) {
+					return entityEntry.getId();
+				}
+				else {
+					// HHH-11426 - best effort to deal with the case of detached entities
+					log.debug( "javax.persistence.PersistenceUnitUtil.getIdentifier may not be able to read identifier of a detached entity" );
+					return getIdentifierFromPersister( entity );
+				}
 			}
 			else {
 				log.debugf(
 						"javax.persistence.PersistenceUnitUtil.getIdentifier is only intended to work with enhanced entities " +
 								"(although Hibernate also adapts this support to its proxies); " +
 								"however the passed entity was not enhanced (nor a proxy).. may not be able to read identifier"
 				);
-				final Class entityClass = Hibernate.getClass( entity );
-				final EntityPersister persister = emf.getSessionFactory().getEntityPersister( entityClass.getName() );
-				if ( persister == null ) {
-					throw new IllegalArgumentException( entityClass + " is not an entity" );
-				}
-				//TODO does that work for @IdClass?
-				return persister.getIdentifier( entity );
+				return getIdentifierFromPersister( entity );			}
+		}
+
+		private Object getIdentifierFromPersister(Object entity) {
+			Class<?> entityClass = Hibernate.getClass( entity );
+			EntityPersister persister = emf.getSessionFactory().getEntityPersister( entityClass.getName() );
+			if ( persister == null ) {
+				throw new IllegalArgumentException( entityClass.getName() + " is not an entity" );
 			}
+			return persister.getIdentifier( entity, null );
 		}
 	}
 }