json – Comparing GSON files in java

So I have a program, where I have a config file in the form of JSON/GSON.

I have an internal resource, that has the default config, and if I ever add a new feature to the application, I would add the config keys there.

I was wondering if there is a way, to compare the two files, and if the external one, is missing a key that the internal one has, it will add that value to the external file.

Please get back to me, Thanks!