InMemory variant looses SubmodelElements about basyx-java-server-sdk

[mhrimaz]

@lenaxus You are right.
the root cause is on this line probably.
@FrankSchnicke Maybe a deep copy and then removing the extra submodelelements would be a quick fix. I can try to fix it if no one is going to do.

[mhrimaz]

@FrankSchnicke you can assign it to me, I will raise a PR.

[FrankSchnicke]

The issue is fixed and a new SNAPSHOT version was uploaded to DockerHub. Thanks again for pointing this out!

[mhrimaz]

However, what would be your suggestion for deep cloning? AAS4j doesn't offer any copy constructor, nor override clone method. I think there should be such a feature, when mutation is allowed and the structure is so complex. It will be difficult to keep track of these mutations.
So now the easy approach would be to serialize to JSON, and get back a new object again, which is not the most efficient way.

[FrankSchnicke]

Thank you very much for pointing out this issue.

@mhrimaz : Currently the only way of creating a deep copy is serialization and deserialization, e.g., to JSON. However, we're planning on adding a deep copy function to AAS4J. Would you like to raise a PR? Otherwise, we will take a look at this and fix it.

[FrankSchnicke]

@mhrimaz are you still interested in doing this PR? If yes, can you estimate until when the PR will be available?

[mhrimaz]

@FrankSchnicke Yes.
Submodel to Json serialization was clear, but I am looking for a way to serialize json to Submodel. (for deep cloning)
If you have a hint here, I appreciate it, otherwise, I have to look in other places in the code to find a way for it.

[FrankSchnicke]

You can use the readReferable method of AAS4J for this.

[mhrimaz]

Exactly tried that:

Submodel submodelDeepCopy = new JsonDeserializer().readReferable(submodelAsJSON, Submodel.class);

but getting an error:

com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Could not resolve subtype of [simple type, class org.eclipse.digitaltwin.aas4j.v3.model.SubmodelElement]: missing type id property 'modelType' (for POJO property 'submodelElements')

However, I am pretty sure my payload is correct, but I have to debug it further to spot the problem.