hibernate/hibernate-orm · error · AnnotationException

@GeneratedValue annotation specified 'strategy=${generationT

Error message

@GeneratedValue annotation specified 'strategy=${generationType}' and 'generator' but the generator name is unnecessary

What it means

IdentifierGeneratorDefinition.buildIdentifierGenerator throws AnnotationException when @GeneratedValue combines GenerationType.IDENTITY or GenerationType.UUID with a non-empty generator name. For these strategies Hibernate derives the generator entirely from the strategy, so a named generator is meaningless and is rejected as a mapping error rather than ignored.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/boot/model/IdentifierGeneratorDefinition.java:112

	@Internal
	public static IdentifierGeneratorDefinition createImplicit(
			String name,
			TypeDetails idType,
			String generatorName,
			GenerationType generationType) {
		// If we were unable to locate an actual matching named generator assume
		// a sequence/table of the given name, make one based on GenerationType.

		return switch ( generationType == null ? GenerationType.SEQUENCE : generationType ) {
			case SEQUENCE -> buildSequenceGeneratorDefinition( name );
			case TABLE -> buildTableGeneratorDefinition( name );
			case AUTO -> new IdentifierGeneratorDefinition(
					name,
					generatorStrategy( generationType, generatorName, idType ),
					singletonMap( IdentifierGenerator.GENERATOR_NAME, name )
			);
			case IDENTITY, UUID -> throw new AnnotationException(
					"@GeneratedValue annotation specified 'strategy=" + generationType
					+ "' and 'generator' but the generator name is unnecessary"
			);
		};
	}

	private static IdentifierGeneratorDefinition buildTableGeneratorDefinition(String name) {
		final TableGeneratorJpaAnnotation tableGeneratorUsage = TABLE_GENERATOR.createUsage( null );
		if ( isNotEmpty( name ) ) {
			tableGeneratorUsage.name( name );
		}
		final Builder builder = new Builder();
		interpretTableGenerator( tableGeneratorUsage, builder );
		return builder.build();
	}

	private static IdentifierGeneratorDefinition buildSequenceGeneratorDefinition(String name) {
		final SequenceGeneratorJpaAnnotation sequenceGeneratorUsage = SEQUENCE_GENERATOR.createUsage( null );

View on GitHub (pinned to fad1729dce)

Solutions

Delete the generator attribute for IDENTITY and UUID strategies
If you actually want a named generator, switch the strategy to SEQUENCE/TABLE and define it (@SequenceGenerator/@TableGenerator or generator definition)
Audit other entities for the same pattern — one fixed annotation usually means siblings have it too

Example fix

// before
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY, generator = "item_gen")
private Long id;

// after
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

Defensive patterns

Strategy: validation

Validate before calling

for (Field f : entity.getDeclaredFields()) {
    GeneratedValue gv = f.getAnnotation(GeneratedValue.class);
    if (gv != null && !gv.generator().isEmpty()
            && (gv.strategy() == GenerationType.IDENTITY || gv.strategy() == GenerationType.UUID)) {
        throw new IllegalStateException("@GeneratedValue on " + f + " must not name a generator for " + gv.strategy());
    }
}

Try / catch

catch (AnnotationException e) {
    throw new IllegalStateException("Remove the generator attribute from @GeneratedValue(strategy=IDENTITY/UUID) ids", e);
}

Prevention

Write a build-time ArchUnit/reflection test enforcing the rule across all entities
Do not copy @GeneratedValue blocks between sequence and identity entities

When it happens

Trigger: An entity or mapped-superclass id annotated like @GeneratedValue(strategy = GenerationType.IDENTITY, generator = "myGen") or @GeneratedValue(strategy = GenerationType.UUID, generator = "uuidGen"). The code path runs when no registered generator definition with that name exists, so Hibernate tries to fabricate one from the strategy and hits the forbidden combination.

Common situations: Copy-paste from sequence-style entities; generators templated by code generators (JHipster-likes, internal scaffolds) that always emit a generator name; code migrated from older Hibernate versions that silently tolerated the extra attribute.

Related errors

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/cb68d02cc29c7734. Report an issue: GitHub.