package ajaxbook.chap3;import java.io.*;import javax.servlet.*;import javax.servlet.http.*;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;import org.w3c.dom.Document;import org.w3c.dom.NodeList;import org.xml.sax.SAXException;public class PostingXMLExample extends HttpServlet {        protected void doPost(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {                String xml = readXMLFromRequestBody(request);        Document xmlDoc = null;        try {            xmlDoc =                     DocumentBuilderFactory.newInstance().newDocumentBuilder()                    .parse(new ByteArrayInputStream(xml.getBytes()));        }        catch(ParserConfigurationException e) {            System.out.println("ParserConfigurationException: " + e);        }        catch(SAXException e) {            System.out.println("SAXException: " + e);        }        /* Note how the Java implementation of the W3C DOM has the same methods         * as the JavaScript implementation, such as getElementsByTagName and          * getNodeValue.         */        NodeList selectedPetTypes = xmlDoc.getElementsByTagName("type");        String type = null;        String responseText = "Selected Pets: ";        for(int i = 0; i < selectedPetTypes.getLength(); i++) {           type = selectedPetTypes.item(i).getFirstChild().getNodeValue();           responseText = responseText + " " + type;        }                response.setContentType("text/xml");        response.getWriter().print(responseText);    }        private String readXMLFromRequestBody(HttpServletRequest request){        StringBuffer xml = new StringBuffer();        String line = null;        try {            BufferedReader reader = request.getReader();            while((line = reader.readLine()) != null) {                xml.append(line);            }        }        catch(Exception e) {            System.out.println("Error reading XML: " + e.toString());        }        return xml.toString();    }}