Java正则表达式-捕获组

    private Set<String> getCodes(String s) {
        Set<String> resultSet = new HashSet<>();
        Matcher matcher = codePattern.matcher(s);
        while (matcher.find()) {
            resultSet.add(matcher.group());
        }
        return resultSet;
    }

private static Pattern codePattern = Pattern.compile("\"code\":\"(\\w+)\",");