JSON and Javascript data objects are essentially directly interchangeable.

In Java, you have to abstract the document and write a lot of code to access, add, remove things etc. - or - because there is no such thing as an untyped POJO in java, you have to set up a ton of things if you want to use real objects.

Instead of using a typed POJO you can deserialize/serialize a Map<String, Object>.

You could also use a POJO for the fields you know and put a map inside for the fields you don't know.

If that's not enough you can use JsonNode, or ObjectNode where you can freely add and remove json values.

Ok, touché, good point.