How do you even parse JSON in Java? I remember in the days of XML, there was a kind of specification standard for the xml (a specification for how to specify a specification?). From that you could generate Java classes that would correspond to the elements of the XML. But for JSON there is no such meta description, so you are stuck with manually parsing the JSON and hoping you catch all nuances?
Typically you create your class manually and map to-and-from json-strings. In a web-context you'd usually let the container handle the serialization/de-serialization (jax-rs), in other contexts I tend to use Google's GSON-library.