This program, in theory, should read words from system.in and store
each in a simple list.  Using, System.out I know for sure that the
list works fine.  It's a problem with my while loop.  It never ends.
I've heard things about using == to compare strings instead of != but
nothing works!  Any help would be greatly appreciated.

Thank you for your time.

import java.util.Scanner;

public class Parse {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);

        Node head = null;
        Node prev = null;
        String read = sc.next();

        while(sc.next() != null){
               Node a = new Node();
              a.data = read;

           if(head == null){
               head = a;
           }else{
               prev.next = a;
           }
           prev = a;
           read = sc.next();
       }
        System.out.println("Works"); // Doesn't get to this point

        for(Node pointer = head; pointer != null; pointer =
pointer.next){
           System.out.println(pointer.data);
       }

    }
}

class Node{
    public Node next;
    public String data;
}