[Java] Junit testing case

How am I supposed to deal with scanner in junit?

Here are my methods I want to test.

Scanner scan = new Scanner(System.in).useDelimiter(" ");

public String prompt_FirstName() { System.out.println("First Name:"); String firstName = scan.next(); return firstName; }

public int prompt_Zip() { System.out.println("Zip:"); int zip = Integer.parseInt(scan.next()); return zip; }