Using java.time.Year in a JPA domain model needs serialization hint

[odrotbohm]

Assume a JPA domain model:

@Entity
class MyEntity {
  javax.time.Year year;
}

With that, running the native image fails with:

Caused by: com.oracle.svm.core.jdk.UnsupportedFeatureError: SerializationConstructorAccessor class not found for declaringClass: java.time.Year (targetConstructorClass: java.lang.Object). Usually adding java.time.Year to serialization-config.json fixes the problem.

[odrotbohm]

This should be solvable outside Spring Native. The reason for the error is that Hibernate doesn't actually have a custom type definition for Year and falls back on its support for Serializable types (which Year implements). It then tries to create copies of Year instances by serializing and deserializing them.

OOTB support for Year is requested in this ticket. As a workaround, you can declare a custom JPA AttributeConverter:

@Immutable
@Converter(autoApply = true)
public class YearAttributeConverter implements AttributeConverter<Year, Integer> {

	@Override
	public Integer convertToDatabaseColumn(Year attribute) {
		return attribute == null ? null : attribute.getValue();
	}

	@Override
	public Year convertToEntityAttribute(Integer dbData) {
		return dbData == null ? null : Year.of(dbData.intValue());
	}
}