XmlSerializer xml = new XmlSerializer();

xml.assembleXml("<root><type>ERROR</type><data>asdlkfajsflkajfs</data></root>");

xml.add("date","TODAY");
System.out.println("type: " + xml.getValueOf("type"));
System.out.println("date: " + xml.getValueOf("date"));
System.out.println("data: " + xml.getValueOf("data"));
System.out.println(xml);

/*
type: ERROR
date: TODAY
data: asdlkfajsflkajfs
<root><type>ERROR</type><data>asdlkfajsflkajfs</data><date>TODAY</date></root>
*/