A man was stabbed and struck in the head with a hammer early Sunday morning, capping a violent weekend in Jersey City. The victim was taken to a local hospital after the incident just after midnight Saturday in the area of Stuyvesant and Romaine avenues, Jersey City spokeswoman Kimberly Wallace-Scalcione said. He is in critical but stable condition. It is believed the man was injured during an altercation with a man he knew. Police recovered a hammer at the scene, Wallace-Scalcione said. Late Friday night a man was shot dead, found behind the wheel of car that crashed into a gate and small wal…