title: Does java have a skip list implementation
body: <p>I find <a href="http://download.oracle.com/javase/6/docs/api/java/util/concurrent/ConcurrentSkipListSet.html" rel="noreferrer"><code>ConcurrentSkipListSet</code></a> in Java Collection Framework, which is backed up with a skip list. But is there a skip list in Java? A set does not work in my use case. I need a indexable list that supports duplicates.</p>