public class ListListIterator { private Iterator> it1; private Iterator it2; ListListIterator( List> listlist) { it1=listlis.iterator(); if(it1.hasNext())) { it2=it1.next.iterator(); } else it2=null; public boolean hasNext() { it(it2==null) return false; while(true) { if(it2.hasNext()) return true; if(!it1.hasNext()) return false; it2=it1.next().iterator(); } public T next() { return it2.next(); } } }