Google's Json Parsing Gson library: What's the difference between JsonElement and JsonObject?

Question

public abstract class JsonElement extends Object 

A class representing an element of Json. It could either be a JsonObject, a JsonArray, a JsonPrimitiv

Answer 1

JsonElement contains common code for all the valid types in JSON:

• JsonObject
• JsonArray
• JsonPrimitive (string, number, boolean)
• JsonNull

This allows you a write a method that takes a JsonElement that works with any of the above types.

Answer 2

JsonElement is the base type for all of the different specific types - it's a base class with common things that all nodes should implement. Logically, this makes a lot of sense.

The thing that all specific types inherits from JsonElement is a good thing for you, too. It allows you to test if an object is a Json node representation, simply by checking if it inherits from JsonElement.

The JsonElement class is available to you as a public class probably not because you'd want to subclass it, but because you'd want to test for its subclasses.