public static boolean isEmail(String s) {
    if (!StringUtil.isEmpty(s)) {
      Pattern p = Pattern.compile("^[\\w\\.-]+@([\\w\\-]+\\.)+[a-z]{2,4}$");
      Matcher m = p.matcher(s);
      return m.matches();
    }
    return false;
  }
public static boolean isEmail(String s)