Java:Scanner.useDelimiter

[alphaoide]

String input = "1 fish 2 fish red fish blue fish";
Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*");
System.out.println(s.nextInt());
System.out.println(s.nextInt());
System.out.println(s.next());
System.out.println(s.next());
s.close();

input in this example is a String. Is there a way to do the same thing with a file? I haven't been able to construct it. Or do I have to read the whole file first and store it in a string?
----
also in the above example the parameter passed to useDelimiter(), what's \\s* for? whitespace?