StringBuilder sb = new StringBuilder();
CharBuffer sb = new CharBuffer();
  public String createSessionId(Env env)  {    String id;    do {      StringBuilder sb = new StringBuilder();      Base64.encode(sb, RandomUtil.getRandomLong());      Base64.encode(sb, Alarm.getCurrentTime());      id = sb.toString();    } while (getSession(env, id, 0) != null);    if (id == null || id.equals(""))      throw new RuntimeException();    return id;  }