Pair<Integer, String> pair = new Pair<>(1, "One");
Integer key = pair.getKey();
String value = pair.getValue();
String input = "one=1&two=2";
Pattern p = Pattern.compile("^(?:w*=d*(?:&|$))+$");
Matcher m = p.matcher(input);
if (m.matches()) System.out.println("Matches!");