import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.swing.JOptionPane;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

public class JDOMSchreiben {

    private final static String DATNAM = "xmlTest.xml";

    private final static File FILE = new File(DATNAM);

    private final static String NAMESPACE = "https://javabeginners.de/xml";

	private Document createDoc(String rootElement) {
        Document doc = new Document();
        Element root = new Element(rootElement, NAMESPACE);
        doc.setRootElement(root);
        return doc;
    }

    private void writeDoc(Document doc) {
        Element e1 = new Element("e1");
        e1.setAttribute("name", e1.getName());
        e1.setAttribute("value", "Wert 1");
        doc.getRootElement().addContent(e1);
        Element e2 = new Element("e2");
        Element n2 = new Element("name");
        n2.setText("e2");
        Element v2 = new Element("value");
        v2.setText("Wert 2");
        e2.addContent(n2);
        e2.addContent(v2);
        doc.getRootElement().addContent(e2);
    }

    private void writeXML(Document doc) {
        Format format = Format.getPrettyFormat();
        format.setIndent("    ");
        try (FileOutputStream fos = new FileOutputStream(FILE)) {
            XMLOutputter op = new XMLOutputter(format);
            op.output(doc, fos);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        JDOMSchreiben jds = new JDOMSchreiben();
        Document doc = jds.createDoc("elements");
        jds.writeDoc(doc);
        jds.writeXML(doc);
    }
}