class ValidateTor {

  public boolean isInteger(String str) {

    if (str == null) {
      return false;
    }
    int length = str.length();
    if (length == 0) {
      return false;
    }
    int i = 0;
    if (str.charAt(0) == '-') {
      if (length == 1) {
        return false;
      }
      i = 1;
    }
    for (; i < length; i++) {
      char c = str.charAt(i);
      if (c < '0' || c > '9') {
        return false;
      }
    }
    return true;
  }

  public  ValidateTor();

}