Embedded abstract class not working with 2.0.0?

How can I use abstract classes properly with 2.0.0 I used to have something similar to the below which used to work on the previous version:

@Entity
public class Root {
  private List<AbstractPlugin> plugins = new ArrayList<>();
  public Root() {
  }
...
}

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = As.EXISTING_PROPERTY, property = "pluginType")
@JsonSubTypes({
    @JsonSubTypes.Type(value = APlugin.class, name = "A_PLUGIN"),
    @JsonSubTypes.Type(value = BPlugin.class, name = "B_PLUGIN")
})
@Embedded
public abstract class AbstractPlugin{
...
}

With 2.0.0 I’m getting the following error: dev.morphia.mapping.MappingException: AbstractPlugin does not have a 0 argument constructor.

Obviously adding an empty constructor doesn’t work either with an error similar to: dev.morphia.mapping.MappingException: Can't instantiate the type AbstractPlugin: null

The db also has the className field with the correct concrete class so after upgrading tbh I’m not sure if previously it was using the pluginType or the className to resolve which class the data represent.

What am I doing wrong and how can I make this work as before?

[evanchooly]

OK. That makes sense. It’s “weird” in some ways but not particularly “wrong.” Morphia isn’t currently set up to make that work, I don’t think. Just thinking through the deserialization code, I’m pretty sure that key/value gets processed and discarded since it’s typically a meta-field. I don’t think it’ll be hard to correct that but I’m reasonably sure it won’t work with what’s out there to day. I’ll file a separate issue to track that.

Morphia has never used the jackson annotations so you probably just got lucky.

[stzanakis]

Thanks for the reply, I think I’ve found why my specific implementation isn’t working… I will update tomorrow if I manage to fix it…