perfetto, risolto con TreeMap:
codice:
TreeMap<String, String> sheetsMap = new TreeMap<String, String>();
sheetsMap.put("ENTRATE", Const.LOCAL_PATH + Const.JSON_LAST_ENTRIES);
sheetsMap.put("USCITE", Const.LOCAL_PATH + Const.JSON_LAST_RELEASES);
Iterator<Entry<String, String>> it = sheetsMap.entrySet().iterator();
while (it.hasNext()) {
            @SuppressWarnings("rawtypes")
            Map.Entry entry = (Map.Entry) it.next();
            System.out.println(entry.getKey().toString() + entry.getValue().toString());
        }
grazie!!