#fixed code
                                private List<RegexRule> readRules(String rulesFile) {
        List<RegexRule> rules = new ArrayList<RegexRule>();

        try {

            InputStream regexStream = getClass().getClassLoader()
                    .getResourceAsStream(rulesFile);
            Reader reader = new InputStreamReader(regexStream, StandardCharsets.UTF_8);
            BufferedReader in = new BufferedReader(reader);
            String line;

            while ((line = in.readLine()) != null) {
                if (line.length() == 0) {
                    continue;
                }
                char first = line.charAt(0);
                boolean sign = false;
                switch (first) {
                case '+':
                    sign = true;
                    break;
                case '-':
                    sign = false;
                    break;
                case ' ':
                case '\n':
                case '#': // skip blank & comment lines
                    continue;
                default:
                    throw new IOException("Invalid first character: " + line);
                }

                String regex = line.substring(1);
                LOG.trace("Adding rule [{}]", regex);
                RegexRule rule = createRule(sign, regex);
                rules.add(rule);

            }
        } catch (IOException e) {
            LOG.error("There was an error reading the default-regex-filters file");
            e.printStackTrace();
        }
        return rules;
    }
#vulnerable code 
                                private List<RegexRule> readRules(String rulesFile) {
        List<RegexRule> rules = new ArrayList<RegexRule>();

        try {

            InputStream regexStream = getClass().getClassLoader()
                    .getResourceAsStream(rulesFile);
            Reader reader = new InputStreamReader(regexStream, "UTF-8");
            BufferedReader in = new BufferedReader(reader);
            String line;

            while ((line = in.readLine()) != null) {
                if (line.length() == 0) {
                    continue;
                }
                char first = line.charAt(0);
                boolean sign = false;
                switch (first) {
                case '+':
                    sign = true;
                    break;
                case '-':
                    sign = false;
                    break;
                case ' ':
                case '\n':
                case '#': // skip blank & comment lines
                    continue;
                default:
                    throw new IOException("Invalid first character: " + line);
                }

                String regex = line.substring(1);
                LOG.trace("Adding rule [{}]", regex);
                RegexRule rule = createRule(sign, regex);
                rules.add(rule);

            }
        } catch (IOException e) {
            LOG.error("There was an error reading the default-regex-filters file");
            e.printStackTrace();
        }
        return rules;
    } 
                            #location 30 
                            #vulnerability type RESOURCE_LEAK