Stephen George King, who had already pleaded guilty to both charges, was also handed a five-year restraining order as he was sentenced in the Royal Court today.
King was with his victim on 6 May at a private address in St Martin when an argument broke out between the two men, who were friends at the time.
King was intoxicated and refused to leave the address when asked to do so.
He then became violent and attacked the victim by punching him several times. He also bit him on the upper arm, causing an injury.
King then armed himself with a knife from the kitchen sink and lunged at his friend, but did not make contact with him.
Police were called just after 23:00.
Authorised Firearms Officers attended and arrested King nearby, shortly after he had left the property.
King was charged and remanded in custody.
Whilst in police custody, King caused damage to a police cell and was further arrested for malicious damage.
He was sentenced to two years and one month in prison for grave and criminal assault and malicious damage in the Royal Court today.