The API should offer abstract implementations for both JsonObject and JsonArray. These implementations will encapsluate a JsonObject and JsonArray delegator respectively , in order to leverage polymorphism.

E.g.

public abstract class AbstractJsonObject implements JsonObject { private final JsonObject delegate; public AbstractJsonObject (final JsonObject delegate) { this.delegate = delegate; } @Override public final JsonArray getJsonArray(final String name) { return this.delegate.getJsonArray(name); } //all other implementations, all delegated  }

Here are some examples of usage (object orientation):

Polymorphic entity: https://github.com/amihaiemil/docker-java-api/blob/master/src/main/java/com/amihaiemil/docker/RtImage.java (extends JsonResource which is the same concept).

2 Articles:

https://www.amihaiemil.com/2017/10/16/javaee8-jsoncollectors-oop-alternative.html
https://www.amihaiemil.com/2017/06/14/non-flushable-jsonobjectbuilder.html (this is for JsonObjectBuilder)

This should be an API addition, obviously, since these classes are provider-agnostic, they are abstract and do not care about any concrete implementation.

If this is wanted, I'll make a PR myself.