How to traverse level by level in tree

Question

Wondering if there were any suggestions on how to efficiently traverse through a tree level by level.
Here is my code for creating the tree.
public static void main(String[] args)
          String userInput = "";
          StringTokenizer tokenizedUserInput;
          int numAdd = 0;
          STree<Integer> completeTree = new STree<Integer>();
          Scanner keyboard = new Scanner(System.in);
          System.out.println("Enter values for tree: ");
          userInput = keyboard.nextLine();
          tokenizedUserInput = new StringTokenizer(userInput, ", ");
          while (tokenizedUserInput.hasMoreTokens())
             numAdd = Integer.parseInt(tokenizedUserInput.nextToken());
             completeTree.add(numAdd);             
        } 

Answer 1

I have found a method to traverse through the tree level by level but it takes in a parameter of a node. I'm
not sure how to take my tree and pass it through the method. Here is the method:
public static <T> String levelByLevel(TNode<T> t)
          LinkedQueue<TNode<T>> q = new LinkedQueue<TNode<T>>();
          TNode<T> p;
          String s = "";
          q.push(t);
          while(!q.isEmpty())
               p = q.pop();
               s += p.nodeValue + " ";
               if(p.left != null)
                    q.push(p.left);
               if(p.right != null)
                    q.push(p.right);
          return s;
}