Use @Mapping with expression to parse OffsetDateTime

I am trying to write a Mapper between my internal Entity class and my DTO class using org.mapstruct.Mapper. The Entity class contains a field startDate of type String that is mapped to a field startDate of type OffsetDateTime.

To map those fields I am using @Mapping with an expression like this:

@Mapper(componentModel = "spring",
        collectionMappingStrategy = CollectionMappingStrategy.TARGET_IMMUTABLE)
public interface InstanceMapper {

    @Mapping(target = "startDate", expression = "java(OffsetDateTime.parse(source.getStartDate()))")
    InstanceDTO toInstanceDTO(Instance source);

    @Mapping(target = "startDate", expression = "java(source.getStartDate().toString())")
    Instance toInstance(InstanceDTO source);
}

The second @Mapping compiles correctly but at compilation I get the following error because of the @Mapping(target = "startDate", expression = "java(OffsetDateTime.parse(source.getStartDate()))"):

[ERROR] project/target/generated-sources/annotations/path/service/mappers/InstanceMapperImpl.java error: cannot find symbol
[ERROR]   symbol:   variable OffsetDateTime
[ERROR]   location: class InstanceMapperImpl

Adding an unused import to the InstanceMapper.java file does not solve the error, as it seems to be removed at compilation.

Seeing as the error is basically a missing import, I'm reasonably sure you can solve this by using a fully qualified name (i.e. java.time.OffsetDateTime) in your expression:

@Mapper(componentModel = "spring",
        collectionMappingStrategy = CollectionMappingStrategy.TARGET_IMMUTABLE)
public interface InstanceMapper {

    @Mapping(target = "startDate", expression = "java(java.time.OffsetDateTime.parse(source.getStartDate()))")
    InstanceDTO toInstanceDTO(Instance source);

    @Mapping(target = "startDate", expression = "java(source.getStartDate().toString())")
    Instance toInstance(InstanceDTO source);
}