解析query string

Map<String, String> paramMap = new HashMap<String, String>();

String queryString="id=1&code=2";

if (queryString != null && queryString.length() > 0) {
                String[] pairs = queryString.split("&");
                for (int x = 0; x < pairs.length; x++) {
                    String[] nameValue = pairs[x].split("=");
                    if (nameValue.length == 2) {
                        paramMap.put(URLDecoder.decode(nameValue[0], encoding),
                                URLDecoder.decode(nameValue[1], encoding));
                    }
                }
            }