jdom xml命名空间 怎么创建 节点呀 在线 多谢了

import org.jdom.Document;import org.jdom.Element;import org.jdom.Namespace;import org.jdom.output.Format;import org.jdom.output.XMLOutputter;public class jdom {    public static void main(String[] args){        Element root = new Element("root");                Element elements = new Element("login");        elements.setAttribute("user","admin");        elements.setAttribute("pass","12345");        root.addContent(elements);                Element elements1 = new Element("chn");        elements1.setNamespace(Namespace.getNamespace("video","https://123"));        elements1.setAttribute("inum","1");        elements1.setAttribute("onum","0");        root.addContent(elements1);                Format format = Format.getPrettyFormat();        XMLOutputter output = new XMLOutputter(format);        System.out.println(output.outputString(root));    }}