Who is Mr. Antonini in The Catcher in the Rye?

Mr. Antolini - Holden's former English teacher at the Elkton Hills School. Mr. Antolini now teaches at New York University. He is young, clever, sympathetic, and likable, and Holden respects him. Holden sometimes finds him a bit too clever, but he looks to him for guidance. Like many characters in the novel, he drinks heavily.

(sparknotes.com/lit/catcher/characters.html)