A DESCRIPTION OF THE PROBLEM :
Use un-synchronized StringBuilder instead of StringBuffer in: sun.net.www.ParseUtil


StringBuffer sb = new StringBuffer();
        if (scheme != null) {
            sb.append(scheme);
            sb.append(':');
        }
        appendSchemeSpecificPart(sb, opaquePart,
                                 authority, userInfo, host, port,
                                 path, query);
        appendFragment(sb, fragment);
        return sb.toString();