Ids<SomeEntity, UUID> argument type mismatch - REST service method

Support
#1

I can’t figure out how to use Id<> and Ids<> in service methods with the REST API. I keep getting hit with errors.

Ids<>

For example, with a method signature such as:

public List<SomeEntity> doSomething(Ids<SomeEntity, UUID> someEntityIds);

As an array

I try posting the IDs as an array:

{
  "somEntityIds": [
    "23465-junk-ID-2e57w474fdg",
    "36783-junk-ID-245ugwhj436"
  ]
}

and then it complains that "23465-junk-ID-2e57w474fdg" is not a JSON Object.

As an object matching the Id class structure

I try matching the structure to Id.java:

{
  "somEntityIds": [
    {
      "id": "23465-junk-ID-2e57w474fdg",
      "entityClass": {
        "_entityName": "prefix$SomeEntity"
      }
    },
    {
      "id": "36783-junk-ID-245ugwhj436",
      "entityClass": {
        "_entityName": "prefix$SomeEntity"
      }
    }
  ]
}

But then it complains that SomeEntity doesn’t contain a entityClass property, as well as java.lang.IllegalArgumentException: argument type mismatch.

As a list of Entity objects

I then try to pass SomeEntity-like objects:

{
  "somEntityIds": [
    {
      "id": "23465-junk-ID-2e57w474fdg",
      "_entityName": "prefix$SomeEntity"
    },
    {
      "id": "36783-junk-ID-245ugwhj436",
      "_entityName": "prefix$SomeEntity"
    }
  ]
}

Which then complains about java.lang.IllegalArgumentException: argument type mismatch without any further information.

Id<>

public SomeEntity doSomething(Id<SomeEntity, UUID> someEntityId);

As a string

{
  "someEntityId": "43576-junk-ID-0245y7hbj3404"
}

If I pass just a raw ID, it complains Expected BEGIN_OBJECT but was STRING.

As an Entity object

{
  "someEntityId": {
    "id": "43576-junk-ID-0245y7hbj3404"
  }
}

This works, except that later in the method when I run em.find() using the ID, this error is thrown: java.lang.IllegalArgumentException: You have provided an instance of an incorrect PK class for this find operation. Class expected : class java.util.UUID, Class received : class java.lang.String..

Note: I tried with and without an _entityName property on the same level as the id property, and both had the same result.

My current workaround

Ids<>

Method signature:

public List<SomeEntity> doSomething(List<SomeEntity> someEntities);

Post:

{
  "someEntities": [
    {
      "id": "23465-junk-ID-2e57w474fdg",
      "_entityName": "prefix$SomeEntity"
    },
    {
      "id": "36783-junk-ID-245ugwhj436",
      "_entityName": "prefix$SomeEntity"
    }
  ]
}

Id<>

Method signature:

public SomeEntity doSomething(UUID someEntityId);

Post:

{
  "someEntityId": "43576-junk-ID-0245y7hbj3404"
}

Conclusion

I would like to use Ids<> and Id<> since they seem to be the more appropriate tools for the job. But how do I do it?