public void TryFinderClass(String str, String matchKey) {
   // String jsonText = "{\"first\": 123, \"second\": [{\"k1\":{\"id\":\"id1\"}}, 4, 5, 6, {\"id\":
   // 123}], \"third\": 789, \"id\": null}";
   String jsonText = str;
   JSONParser parser = new JSONParser();
   KeyFinder finder = new KeyFinder();
   // finder.setMatchKey("id");
   finder.setMatchKey(matchKey);
   try {
     while (!finder.isEnd()) {
       parser.parse(jsonText, finder, true);
       if (finder.isFound()) {
         finder.setFound(false);
         System.out.println(matchKey + " found:");
         System.out.println(finder.getValue());
       }
     }
   } catch (ParseException pe) {
     System.out.println(pe.getMessage());
   }
 }