java - How to retrieve field values by passing field name using JPOS ISO8583 message format -

i want retrieve field values passing filed name .in order achieve have implemented method loop through isomsg object , if found match passed filed name returns .my requirement read .xml file once , have static map using on next time retrieve corresponding value passing field name in order achieve there way retrieve field in config xml.

protected static void getiso8583valuebyfieldname(isomsg isomsg, string fieldname) {  (int = 1; <= isomsg.getmaxfield(); i++) {    if (isomsg.hasfield(i)) {      if (isomsg.getpackager().getfielddescription(isomsg, i).equalsignorecase(fieldname)) {       system.out.println(           "    found field -" + + " : " + isomsg.getstring(i) + " " + isomsg.getpackager()               .getfielddescription(isomsg, i));        break;      }    }  }  

}

you can define enum field names, mapped field numbers. please note field names may vary packager packager, solution kind of brittle, it's better use enum, or constants.