Sir Bobby has chosen to hand him the new deal despite a string of below par performances this season, showing again the manager’s absolute faith in the youngster’s ability to make it right to the top.
After signing the deal JJ told the official website: "Moving to Newcastle United 18 months ago has proved to be a terrific career move for me.
"This is a fantastic club and a marvellous place to play your football.
"I hope over the next five years we can build on our success over the last two seasons and I am looking forward to being involved with a strong and successful team.
"I would also like to thank the fans who have given me fantastic support since I joined the club."