private String addContextPath() {
        Matcher matcher = pattern.matcher(body);
        boolean result = matcher.find();
        StringBuffer sb = new StringBuffer();
        while(result) {
            String matched = matcher.group();
            String replacement = "";
            if (matched.contains("/stylesheets/")) {
                replacement = matched.replace("/stylesheets/", context_path + "/stylesheets/");
            } else if (matched.contains("/javascripts/")) {
                replacement = matched.replace("/javascripts/", context_path + "/javascripts/");
            }
            matcher.appendReplacement(sb, replacement);
            result = matcher.find();
        }
        matcher.appendTail(sb);
        return new String(sb);
    }