Possible to flat json object

[Prototype1]

Imagine we have some json

{
"id": "Bla",
"name": "x",
"source": {
"id": "2"
}
}

And we wanna have this output:

public class Record{ public String id; public String name; public String sourceId; }

How could we do it? Right now I use constructor mapping with a temporary Source object which then is used to set the consponding String in the Record class but there has to be a better way or?