Ray J ARRESTED -- Allegedly Spit on Cops [PHOTO UPDATE]

Ray J was busted by Beverly Hills cops Friday night after a disturbance at a swanky hotel allegedly turned into a violent confrontation with officers ... TMZ has learned.

Law enforcement sources tell us Beverly Hills PD got a call from someone claiming Ray J was causing a ruckus inside a bar at the Beverly Wilshire Hotel ... and officers were dispatched.

We're told hotel staff asked Ray J to leave, but he refused. TMZ obtained photos of officers on scene questioning Ray and an unidentified woman ... shortly before he was taken into custody -- and we're told he did not go quietly.

Once cuffed in the back seat of a patrol unit ... Ray allegedly kicked out a window of the vehicle.

Right now Ray is getting booked by Bev Hills PD for trespassing, vandalism, resisting arrest, and battery ... according to our sources.

We're told the battery is for allegedly spitting on an officer during the arrest.