Is it possible to have the same classes be @Entity and @Embedded? (2.0.2)

I am storing certain objects as both separate entities in a collection and embedded within other entities in different collections (for caching, basically). Prior to 2.0 I have been using the same class for both without any issues, however in 2.0 it is causing various issues.

Now that @Embedded has to be used on types, the constraints don’t let me use both @Embedded and @Entity on the same class, and they also neither allow an @Embedded class with an @Id property, nor they allow an @Entity class without one.

The structure I have is kind of like this (actually there is a base class for Job to make this possible but just to have a shorter example):

@Entity("job")
@Indexes(Index(fields = [Field("shifts.startTime", type = IndexType.ASC)]))
class Job(
    @Id var id: ObjectId,
    var shifts: List<Shift>,
)

class Shift(
    @Id var id: ObjectId,
    var startTime: Date,
)

// and also
@Entity("shiftAndJob")
class ShiftAndJob(
    var shift: Shift,
    var job: Job,
)

• Mapping fails with a ValidationException on the shifts.startTime index, it’s not being found.

• If I try to retrieve a Job entity, the operation fails with org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class Shift.

• Validations fail when trying to query ShiftAndJob for e.g. job.shifts or shift.startTime

So basically I want to use the Job class here as both an embedded object and its own separate entity and I can’t figure out what’s the way to do so in 2.0 (in 1.* it all just worked regardless of @Embedded), are there any “best practices” on how to achieve this without cloning the classes altogether or using too much inheritance?

Driver Version: 4.0.5
Morphia Version: 2.0.2

[evanchooly]

You can just use @Entity on the type and then also embed. The annotations are there to mark which classes to map and which set of validations to apply, to perhaps oversimplify things a bit. But an entity can also be embedded at that point because it’s already mapped. I believe there are some unit tests that do just that.

[DefiantCatgirl]

Yes, it’s working fine, thank you!