code: public static void clearJarCache()
    {
      LruCache<PathImpl,Jar> jarCache = _jarCache;
      
      if (jarCache == null)
        return;
  
      ArrayList<Jar> jars = new ArrayList<Jar>();
      
      synchronized (jarCache) {
        Iterator<Jar> iter = jarCache.values();
        
        while (iter.hasNext())
          jars.add(iter.next());
      }
  
      for (int i = 0; i < jars.size(); i++) {
        Jar jar = jars.get(i);
          
        if (jar != null)
          jar.clearCache();
      }
    }
docs: Clears all the cached files in the jar.  Needed to avoid some
  windows NT issues.