public void setXPPFactory(XmlPullParserFactory xppFactory) {
        this.xppFactory = xppFactory;
    }
<p>Reads a Document from the given <code>Reader</code></p>

@param reader   is the reader for the input
@param systemID is the URI for the input
@return the newly created Document instance
@throws DocumentException if an error occurs during parsing.
@throws IOException if an error occurs during reading
@throws XmlPullParserException if an error occurs creating a pull parser
xmppserver/src/main/java/org/dom4j/io/XMPPPacketReader.java