Enumeration with Circular Buffer

Question

Hi, im having trouble with the enumeration of Circular Buffer .
I had compilation errors with the Ring Buffer Class, it keeps pointing to public Enumeration elements () {return new RingBufferEnumeration(this);}
Any advice ? Thanks
This is the RingBufferEnumeration Class code
public class RingBufferEnumeration implements Enumeration {
private RingBufferNode firstFree, firstFilled;
     public RingBufferEnumeration(RingBufferNode a) {
          firstFree = new RingBufferNode(a);
          firstFilled = firstFree;
          firstFree.next = firstFree;
public boolean hasMoreElements(){
  return firstFilled != firstFree;
public Object nextElement () {
return firstFilled= firstFilled.next;
}this is the Ring Buffer Code
public class RingBufferQueue implements Queue {
      * initialize an empty ring buffer queue
     public RingBufferQueue () {
          firstFree = new RingBufferNode(firstFilled);
          firstFilled = firstFree;
          firstFree.next = firstFree;
     private RingBufferNode firstFree, firstFilled;
      * Determines whether the collection is empty
      * @return true if the collection is empty
     public boolean isEmpty() { return firstFilled == firstFree; }
      * Determines number of elements in collection
      * @return number of elements in collection as integer
     public int size () {
          int count = 0;
          RingBufferNode p = firstFilled;
          for (; p != firstFree; p = p.next) count++;
          return count;
      * Yields enumerator for collection
      * @return an <code>Enumeration</code> that will yield the elements of the collection
      * @see java.util.Enumeration
     public Enumeration elements () {return new RingBufferEnumeration(this);}
      * add a new value to end of the collection
      * @param value element to be inserted into collection
     public synchronized void addLast (Object val) {
          if (firstFree.next == firstFilled)
               firstFree.next = new RingBufferNode(firstFree.next);
          firstFree.value = val;
          firstFree = firstFree.next;
      * access the first value in collection
      * @return element at front of collection
      * @exception java.util.NoSuchElementException no matching value
     public Object getFirst () {
          if (firstFilled == firstFree) throw new NoSuchElementException();
          return firstFilled.value; }
      * remove first value in collection
      * @exception java.util.NoSuchElementException no matching value
     public synchronized void removeFirst () {
          if (firstFilled == firstFree) throw new NoSuchElementException();
          firstFilled = firstFilled.next;
class RingBufferNode {
     public Object value;
     public RingBufferNode next;
     public RingBufferNode (RingBufferNode n)
          { next = n; }
}

Answer 1

im not sure is it a RingBufferNode but, im sure it is not indexed data for ring Buffer
My IndexDeque is working correctly
public Enumeration elements () { return new IndexedEnumeration(this); }IndexedEnumeration
public class IndexedEnumeration implements Enumeration {
      * initialize newly created IndexedEnumeration
      * @param d collection to enumerate over
     public IndexedEnumeration (Indexed d) { data = d; }
     private Indexed data;
     private int index = 0;
      * see if enumeration should continue
      * @return true if enumeration has at least one more element
     public boolean hasMoreElements () { return index < data.size(); }
      * get next element in enumeration
      * @return value of next element in enumeration
     public Object nextElement () { return data.elementAt(index++); }
}