Scanner problems (java)

[Zidaan]

my problem is the following:

The program will run until the user press "Enter" but indicated nothing.

I thought something like this:

Scanner sc = new Scanner (System.in); 

String = into sc.next (); 

if (in == null) 
System.exit (0);

but because the scanner does not accept empty tokens it does not work so!
(enter enter-pressure leads to a new line in the terminal window, but in the program hands "no".)

If anyone has any solution to my problem, I would be very grateful!

[Modifier]

Scanner sc = new Scanner (System.in); 
String = into sc.nextLine (); 
if (in.equals ("")) 
   System.exit (0);

[Zidaan]

  Scanner scanner input = new Scanner (System.in); 
  while ((String input = scannerInput.nextLine ())! = "") ( 
  )

Do I mean it right?