I should have efficient Collections method

This is my method

 private java.util.List[] getURLList(java.util.List list) {
    Hashtable ht = new Hashtable();
    for (int i = 0; i < list.size(); i++) {
      String url = list.get(i).toString();
      String array[] = url.split("/");

      String domain = array[0];
      if (array[0].toLowerCase().startsWith("http")) {
        domain = array[2];
        domain = domain + array[4];
      }
      else {
        domain = domain + array[2];
      }

      ArrayList sublist = (ArrayList) ht.get(domain);
      if (sublist == null) {
        sublist = new ArrayList();
      }
      sublist.add(url);
      ht.put(domain, sublist);
    }
    return (List[]) Collections.list(ht.elements()).toArray(new ArrayList[0]);
  }







from : https://www.experts-exchange.com/questions/21102101/Help-needed-to-make-this-collections-method-much-efficient.html (Answered by CEHJ)
private static java.util.List[] getUrlList(java.util.List list) {
          Hashtable hostToUrls = new Hashtable();
          try {
               for (int i = 0; i < list.size(); i++) {
                    URL url = new URL((String) list.get(i));
                    String hostKey = url.getHost();
                         String protocol=url.getProtocol();
                    //     System.err.println(url.getProtocol() );
                    // Could be a Set if no duplicates required
                    ArrayList urlsForHost = (ArrayList)hostToUrls.get(protocol+hostKey);
                    if (urlsForHost == null) {
                         urlsForHost = new ArrayList();
                         urlsForHost.add(url);
                         hostToUrls.put(protocol+hostKey, urlsForHost);
                    }
                    else {
                         urlsForHost.add(url);
                    }
               }
          }
          catch (MalformedURLException e) {
               return null;
          }
          int numberOfLists = hostToUrls.size();
          return (java.util.List[]) Collections.list(hostToUrls.elements()).toArray(new ArrayList[numberOfLists]);
     }




Hello all,

This question was asked already by me. But I am looking at much more efficient method. The reason is although CEHJ's method is efficient, it is not giving correct sets. Actually my method gives the correct sets. But it is less efficient method than CEHJ's

So I need the correct results and should increase the performance of method than CEHJ's and my method.


for your testing,

Here is the test sample
http://www.geocities.com/sudhakar_koundinya/testsample.html (If u place the problem - copy the URL in location bar and press enter. Then it works :-D )

Actually what I am thinking is

return (List[]) Collections.list(ht.elements()).toArray(new ArrayList[0]); this line is giving poor performance results.

Any ideas are welcome from you guys

thank you
Sudhakar