private static String canonicalizeQueryParameters(CanonicalHttpRequest request) throws UnsupportedEncodingException { String result = ""; if (null != request.getParameterMap()) { List<ComparableParameter> parameterList = new ArrayList<ComparableParameter>(request.getParameterMap().size()); for (Map.Entry<String, String[]> parameter : request.getParameterMap().entrySet()) { if (!JwtConstants.JWT_PARAM_NAME.equals(parameter.getKey())) { parameterList.add(new ComparableParameter(parameter)); } } Collections.sort(parameterList); result = percentEncode(getParameters(parameterList)); } return result; }