Java definitely makes it harder to work with json but the only problem I run in to is that I need classes (which I just autogenerate) for every json object. Serializing and deserializing json is a one liner once you have classes set up for them to deserialize into. Again, it is definitely harder than in Python and Javascript but I work with Java and json every day and it's generally only a huge difficulty if you need a strange edge case.

EDIT: also, java is bad at dealing with json if the api could return data in multiple different schemas and you don't know which one it is until you parse it but I've only run into this once and it's just bad API design.