hibernate/hibernate-orm · error · MappingException

Only classes (not interfaces) may be mapped as @Entity : " +

Error message

Only classes (not interfaces) may be mapped as @Entity : " + classDetails.getName()

What it means

Error "Only classes (not interfaces) may be mapped as @Entity : " + classDetails.getName()" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/boot/models/xml/internal/ManagedTypeProcessor.java:140

						);
					}
			);

			DynamicModelHelper.prepareDynamicClass( classDetails, jaxbEntity, xmlDocumentContext );
		}
		else {
			memberAdjuster = ManagedTypeProcessor::adjustCompleteNonDynamicTypeMember;
			final String className = XmlProcessingHelper.determineClassName( jaxbRoot, jaxbEntity );
			classDetails = (MutableClassDetails) classDetailsRegistry.resolveClassDetails( className );
			classAccessType = coalesce(
					jaxbEntity.getAccess(),
					jaxbRoot.getAccess(),
					xmlDocumentContext.getEffectiveDefaults().getDefaultPropertyAccessType(),
					defaultAccessTypeFromDefaultAccessor( xmlDocumentContext ),
					AccessType.PROPERTY
			);
			if ( classDetails.isInterface() ) {
				throw new MappingException( "Only classes (not interfaces) may be mapped as @Entity : " + classDetails.getName() );
			}

			classDetails.forEachPersistableMember( memberDetails -> {
				final var mutableMemberDetails = (MutableMemberDetails) memberDetails;
				mutableMemberDetails.clearAnnotationUsages();
			} );
		}

		classDetails.clearAnnotationUsages();

		// In metadata-complete mode the XML is the sole source of truth — annotations have just
		// been cleared, so the chosen access type must be stamped on the class regardless of
		// whether it came from XML or from a fallback.
		applyAccessAnnotation( classAccessType, classDetails, xmlDocumentContext );

		// from here, processing is the same between override and metadata-complete modes
		// (aside from the dynamic model handling)

View on GitHub (pinned to fad1729dce)

Solutions

1. Remove @Entity from the interface; map a concrete class instead, or use the interface only as a target of associations via targetEntity.

Example fix

Remove @Entity from the interface; map a concrete class instead, or use the interface only as a target of associations via targetEntity.

When it happens

Trigger: An hbm.xml / orm.xml mapping document violates a mapping rule during bootstrap.

Common situations: Legacy XML mappings with invalid combinations (column+formula, mixed inheritance, missing identifiers, bad extends references).

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/a9bc9d153a48b072. Report an issue: GitHub.