public static List<Pair<String, String>> parser(final String json, final Set<String> fieldNames) {
        if (CollectionUtils.isEmpty(fieldNames) || StringUtils.isBlank(json)) {
            return Lists.newArrayList();
        }
        return fieldNames.stream().filter(StringUtils::isNoneBlank)
                .map(field -> Pair.of(field, parser(json, field)))
                .filter(pair -> StringUtils.isNoneBlank(pair.getRight()))
                .collect(Collectors.toList());
    }
parser JSON.
@param json json Map
@param fieldNames params
@return str.
shenyu-plugin/shenyu-plugin-security/shenyu-plugin-cryptor/src/main/java/org/apache/shenyu/plugin/cryptor/utils/JsonUtil.java