code: public static String [] getAvailableNames() {
  
              UResourceBundle numberingSystemsInfo = UResourceBundle.getBundleInstance(ICUData.ICU_BASE_NAME, "numberingSystems");
              UResourceBundle nsCurrent = numberingSystemsInfo.get("numberingSystems");
              UResourceBundle temp;
  
              String nsName;
              ArrayList<String> output = new ArrayList<String>();
              UResourceBundleIterator it = nsCurrent.getIterator();
              while (it.hasNext()) {
                  temp = it.next();
                  nsName = temp.getKey();
                  output.add(nsName);
              }
              return output.toArray(new String[output.size()]);
      }
docs: Returns a string array containing a list of the names of numbering systems
  currently known to ICU.