common_helper/src/main/java/com/xiongyingqi/util/xml/AbstractStaxXMLReader.java
protected String toQualifiedName(QName qName) {
        String prefix = qName.getPrefix();
        if (!StringUtils.hasLength(prefix)) {
            return qName.getLocalPart();
        } else {
            return prefix + ":" + qName.getLocalPart();
        }
    }
protected String toQualifiedName(QName qName) {
        String prefix = qName.getPrefix();
        if (!StringUtils.hasLength(prefix)) {
            return qName.getLocalPart();
        } else {
            return prefix + ":" + qName.getLocalPart();
        }
    }
Convert a {@code QName} to a qualified name, as used by DOM and SAX.
The returned string has a format of {@code prefix:localName} if the
prefix is set, or just {@code localName} if not.

@param qName the {@code QName}
@return the qualified name