Java tutorial
import java.io.File; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; public class Main { public static void main(String[] argv) throws Exception { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setValidating(true); factory.setExpandEntityReferences(false); Document doc = factory.newDocumentBuilder().parse(new File("filename")); Element element = doc.getElementById("key1"); element.setAttribute("newAttrName", "attrValue"); element.setAttribute("newAttrName", "<>&\"'"); element.removeAttribute("value"); boolean has = element.hasAttribute("value"); // true String attrValue = element.getAttribute("value"); // mydefault } }