private void required(String attributeName,Resource attributValue,boolean exists) throws ApplicationException {
  if (attributValue == null)   throw new ApplicationException("invalid attribute constellation for the tag zip","attribute [" + attributeName + "] is required, if action is ["+ action+ "]");
  if (exists && !attributValue.exists())   throw new ApplicationException(attributeName + " resource [" + attributValue+ "] doesn't exist");
 else   if (exists && !attributValue.canRead())   throw new ApplicationException("no access to " + attributeName + " resource ["+ attributValue+ "]");
}

private void required ( String attributeName , Resource attributValue , boolean exists ) throws ApplicationException { if ( attributValue == null ) throw new ApplicationException ( "invalid attribute constellation for the tag zip" , "attribute [" + attributeName + "] is required, if action is [" + action + "]" ) ; if ( exists && ! attributValue . exists ( ) ) throw new ApplicationException ( attributeName + " resource [" + attributValue + "] doesn't exist" ) ; else if ( exists && ! attributValue . canRead ( ) ) throw new ApplicationException ( "no access to " + attributeName + " resource [" + attributValue + "]" ) ; }
throw a error if the value is empty ( null )
