Well since you can't be arsed to post a link supporting your views, I did the search and I found that :
Frida Ghitis, journalist on CNN, definitely states he is not a journalist
Peter Greste on stuff, another actual journalist, says he's not and why
Gabriel Schoenfeld, a columnist for The Bulwark, says the question is irrelevant and why
David French, journalist of National Review, calls him a leader of a non-state hostile intelligence service
On Wikipedia, his page states that he has been a member of the Australian Journalist Union
Kathy Kiely and Laurel Leff, two professors of journalism at The Conversation, explain why calling Assange a journalist is a bad mistake
Of course, I also found quite a lot of articles supporting the thesis that Assange is a journalist.
What I did not find is any report of a judge stating he is not.
So, citation please.