Matthew Chmielinski had avoided a jail sentence for a violent assault and for spitting at a police officer.
When officers arrived at the crime scene last May, having been called to a ‘disturbance’, they found the victim outside his flat with ‘significant facial injuries’.
He had been punched and kicked in the head, and a window had been smashed.
Chmielinski was found unresponsive in his victim's bedroom.
Paramedics treated the 21-year-old, who was arrested on suspicion of grave and criminal assault and malicious damage.
He was taken to the hospital, where he spat on a police officer.
Chmielinski pleaded guilty to the three offences in the Magistrate's Court on 2 January and was sentenced by the Royal Court today (21 March)
He has been ordered to do 360 hours of community service, put on a two-year probation order and has been given a restraining order.
DS Jim McGranahan says the police will not tolerate acts of unprovoked violence as a police force or as a society.
"States of Jersey Police will continue to work hard, and in conjunction with the public and victims, to keep our streets and community safe."

States set to debate dogs on beach restriction times
Over 300 Jersey students have received Meningitis B vaccine
Government begins recouping over £278m in 2019 tax
Could al-fresco dining and more festivals make St Helier vibrant again?
More cyclists travelling 'at dangerous speeds' in pedestrian areas
Call for more eastern play facilities as Sandy Park reopens
Jersey Zoo welcomes its first Red Panda
Major survey of experiences of life in Jersey with a disability