read

WriteXMLFile.java
~~~~~~~~~~~~~~~~~~~~
package javat;
import java.io.FileWriter;
import java.io.IOException;
import org.jdom2.Attribute;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.output.Format;
import org.jdom2.output.XMLOutputter;

public class WriteXMLFile {
	public static void main(String[] args) {

	  try {

		Element company = new Element("companys");
		Document doc = new Document(company);

		Element[]	 staff = new Element[10];
		staff[2] = new Element("staff");


		staff[2].setAttribute(new Attribute("id", "1"));
		staff[2].addContent(new Element("firstname").setText("yong"));
		staff[2].addContent(new Element("lastname").setText("mook kim"));
		staff[2].addContent(new Element("nickname").setText("mkyong"));
		staff[2].addContent(new Element("salary").setText("199999"));

		doc.getRootElement().addContent(staff[2]);

		Element staff3 = new Element("staff");
		staff3.setAttribute(new Attribute("id", "2"));
		staff3.addContent(new Element("firstname").setText("low"));
		staff3.addContent(new Element("lastname").setText("yin fong"));
		staff3.addContent(new Element("nickname").setText("fong fong"));
		staff3.addContent(new Element("salary").setText("188888"));

		doc.getRootElement().addContent(staff3);

		// new XMLOutputter().output(doc, System.out);
		XMLOutputter xmlOutput = new XMLOutputter();

		// display nice nice
		xmlOutput.setFormat(Format.getPrettyFormat());
		xmlOutput.output(doc, new FileWriter("d:\\file.xml"));

		System.out.println("File Saved!");
	  } catch (IOException io) {
		System.out.println(io.getMessage());
	  }
	}
}



MOdified.
~~~~~~~~~~~~~~~~
http://examples.javacodegeeks.com/core-java/xml/parsers/documentbuilderfactory/modify-xml-file-in-java-using-dom-parser-example/
~~~~~~~~~~~~~~~~~~~~~~~~~~

testFile.xml:
~~~~~~~~~~~~~~~
<?xml version="1.0"?>
<company>

	<employee id="1">
		<firstname>James</firstname>
		<lastname>Harley</lastname>
        <email>james@example.org</email>
		<department>Human Resources</department>
		<salary>1000</salary>
	</employee>

	<employee id="2">
		<firstname>John</firstname>
		<lastname>May</lastname>
		<email>john@example.org</email>
		<department>Logistics</department>
		<salary>400</salary>
	</employee>

</company>

ReadAndModifyXMLFile.java:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
package com.javacodegeeks.java.core;

import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class ReadAndModifyXMLFile {

	public static final String xmlFilePath = "C:\\Users\\nikos7\\Desktop\\files\\testFile.xml";

	public static void main(String argv[]) {

		try {

			DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();

			DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();

			Document document = documentBuilder.parse(xmlFilePath);

			// Get employee by tag name
			//use item(0) to get the first node with tage name "employee"
			Node employee = document.getElementsByTagName("employee").item(0);

			// update employee , set the id to 10
			NamedNodeMap attribute = employee.getAttributes();
			Node nodeAttr = attribute.getNamedItem("id");
			nodeAttr.setTextContent("10");

			// append a new node to the first employee
			Element address = document.createElement("address");

			address.appendChild(document.createTextNode("34 Stanley St."));

			employee.appendChild(address);

			// loop the employee node and update salary value, and delete a node
			NodeList nodes = employee.getChildNodes();

			for (int i = 0; i < nodes.getLength(); i++) {

				Node element = nodes.item(i);

				if ("salary".equals(element.getNodeName())) {
					element.setTextContent("2000000");
				}

				// remove firstname
				if ("firstname".equals(element.getNodeName())) {
					employee.removeChild(element);
				}

			}

			// write the DOM object to the file
			TransformerFactory transformerFactory = TransformerFactory.newInstance();

			Transformer transformer = transformerFactory.newTransformer();
			DOMSource domSource = new DOMSource(document);

			StreamResult streamResult = new StreamResult(new File(xmlFilePath));
			transformer.transform(domSource, streamResult);

			System.out.println("The XML File was ");

		} catch (ParserConfigurationException pce) {
			pce.printStackTrace();
		} catch (TransformerException tfe) {
			tfe.printStackTrace();
		} catch (IOException ioe) {
			ioe.printStackTrace();
		} catch (SAXException sae) {
			sae.printStackTrace();
		}
	}
}

testFile.xml:
~~~~~~~~~~~~~~~~~~~~~
<?xml version="1.0" encoding="UTF-8" standalone="no"?><company>

	<employee id="10">

		<lastname>Harley</lastname>
        <email>james@example.org</email>
		<department>Human Resources</department>
		<salary>2000000</salary>
	    <address>34 Stanley St.</address><
	/employee>

	<employee id="2">
		<firstname>John</firstname>
		<lastname>May</lastname>
		<email>john@example.org</email>
		<department>Logistics</department>
		<salary>400</salary>
	</employee>

</company>