package org.exolab.castor.mapping.loader.collection.handler;
   
   import java.util.Enumeration;
   import java.util.Iterator;
   
   import org.exolab.castor.mapping.CollectionHandler;
   import org.exolab.castor.mapping.loader.CollectionHandlers;
   import org.exolab.castor.mapping.loader.J2CollectionHandlers.IteratorEnumerator;
   
  public final class IteratorCollectionHandler<T> implements CollectionHandler<T> {
    public Object add(Object collection, T object) {
      // -- do nothing, cannot add elements to an
      // enumeration
      return null;
    }
  
    @SuppressWarnings("unchecked")
    public Enumeration<T> elements(Object collection) {
      if (collection == null) {
        return new CollectionHandlers.EmptyEnumerator<T>();
      }
      return new IteratorEnumerator<T>((Iterator<T>) collection);
    }
  
    public int size(Object collection) {
      // -- Nothing we can do without iterating over the
      // iterator
      return 0;
    }
  
    public Object clear(Object collection) {
      return null;
    }
  
    public String toString() {
      return "Iterator";
    }
  }