CK's Developer Blog

The below Java file shows how to create a XML Document, append Elements to it and finally convert the XML Document to String representation. I am posting this as I noticed many of the  developers in my team were using StringBuffer (or StringBuilder) to create the String representation of the XML.

import java.io.StringWriter;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Result;
import javax.xml.transform.Transformer;
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;

/**
 * Class to construct string representation of XML rather than using StringBuffer or  StringBuilder  which is cumbersome.
 *
 */
public class XMLStringCreator {

 private Document document = null;

 public XMLStringCreator() throws ParserConfigurationException {
 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
 DocumentBuilder builder = factory.newDocumentBuilder();
 document = builder.newDocument();
 }

 /**
 * Creates an xml element with the details passed.
 * @param elementName XML element name
 * @param textNodeValue null if there is no text node value to be associated.
 * @param attributesNameValueMap should pass null or an empty Map if no attributes
 * @return The XML Element with attributes specified (if any)
 */
 public Element createElement(String elementName, String textNodeValue, Map<String, String> attributesNameValueMap) {
 Element element = document.createElement(elementName);

 if (textNodeValue != null) {
 element.appendChild(document.createTextNode(textNodeValue));
 }

 if (attributesNameValueMap == null || attributesNameValueMap.size() == 0) {
 return element;
 } else {
 return addAttributes(element, attributesNameValueMap);
 }//eof else

 }

 /**
 * This method should be called only once. Its the responsibility of the caller to ensure this.
 * @param root The root xml element
 */
 public void addRootElement(Element root) {
 document.appendChild(root);
 }

 /**
 * Appends child to parent xml element (or node)
 * @param parent The parent XML element
 * @param child The child xml element
 */
 public void addChild(Element parent, Element child) {
 parent.appendChild(child);
 }

 /**
 * returns the XML string constructed so far with the other methods of this class.
 * @return xml string representation.
 * @throws Exception
 */
 public String getXMLString() throws Exception {
 StringWriter writer = new StringWriter();
 Result result = new StreamResult(writer);
 Transformer transformer = TransformerFactory.newInstance().newTransformer();
 transformer.transform(new DOMSource(document), result);
 return writer.toString();
 }

 /**
 * Adds attributes to XML element
 * @param element
 * @param attributesNameValueMap
 * @return The xml element with the attributes.
 */
 private Element addAttributes(Element element, Map<String, String> attributesNameValueMap) {

 for (String key : attributesNameValueMap.keySet()) {
 element.setAttribute(key, attributesNameValueMap.get(key));
 }//eof for loop

 return element;
 }

 @Override
 public String toString(){
 throw new UnsupportedOperationException("Please use the method getXMLString instead");
 }

}