code: protected Integer attributeAsInt(XMLStreamReader reader, String attributeName, Map<String, String> expressions)
        throws XMLStreamException
     {
        String attributeString = rawAttributeText(reader, attributeName);
  
        if (attributeName != null && expressions != null && attributeString != null &&
            attributeString.indexOf("${") != -1)
           expressions.put(attributeName, attributeString);
  
        return attributeString != null ? Integer.valueOf(getSubstitutionValue(attributeString)) : null;
     }
docs: convert an xml element in String value
  
  @param reader the StAX reader
  @param attributeName the name of the attribute
  @param expressions The expressions
  @return the string representing element
  @throws XMLStreamException StAX exception