has Johnny ever been in jail? i hope he hasn't and what did he do to get in to jail if he did?

yes on September 13 1994 he was arrested for trashing Mark Hotel's room in New York City with Kate moss present in the room.
here's the pic of johnny depp in handcuffs.

Oh,and one more thing at that time johnny was in the habit of checking into hotels under the name of "Mr.Donkey Penis"
he said it made the wake up calls more interesting...
hahahaha ♥♥

and in january 1999 johnny depp was arrested for fighting with paparazzis outside the restaurant in london

yes, he has went to jail for crashing a hotel room its been said in his own autobiographery.

In 1994, Depp was arrested and questioned by police for allegedly causing serious damage to a New York City hotel suite. He was arrested again in 1999 for brawling with paparazzi outside a restaurant while dining in London with Paradis