private boolean isHHSign(String str){
  boolean sign=true;
  try {
    char r=(char)Integer.parseInt(str,16);
  }
 catch (  NumberFormatException e) {
    sign=false;
  }
  return sign;
}

private boolean isHHSign ( String str ) { boolean sign = true ; try { char r = ( char ) Integer . parseInt ( str , 16 ) ; } catch ( NumberFormatException e ) { sign = false ; } return sign ; }
dmitri ilyin : makes sure if the string is hh encoded sign .
