Convert Key Example with XML

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package edu.sc.cse;

import java.io.*;
import java.net.*;

import javax.servlet.*;
import javax.servlet.http.*;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.output.XMLOutputter;
/**
 *
 * @author jmvidal
 */
public class AjaxResponseServlet extends HttpServlet {
   
    private static final long serialVersionUID = 1L;    
    
    /** 
    * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
    * @param request servlet request
    * @param response servlet response
    */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
          // key is the parameter passed in from the javascript
        // variable named url (see index.html)
        String key = request.getParameter("key");
        StringBuffer returnXML = null; 
        if (key != null) {

            // extract the first character from key
            // as an int, then convert that int to a String
            int keyInt = key.charAt(0);
            
            // setup the response
            response.setContentType("text/xml");
            response.setHeader("Cache-Control", "no-cache");
            
            //Two ways of generating XML
            //String output = createStringBufferXML(keyInt);
       //     String output = createJdomXML(keyInt);
            String output = createDom4jXML(keyInt);
            
            // write out the xml string
            response.getWriter().write(output);
        }
        else {
            // If key comes back as a null, return a question mark.
            response.setContentType("text/xml");
            response.setHeader("Cache-Control", "no-cache");
            response.getWriter().write("?");
        }
    } 
    
    public String createStringBufferXML(int keyInt) {
        StringBuffer returnXML = null;
        returnXML = new StringBuffer("\r\n<converted-values>");
        returnXML.append("\r\n<decimal>" + Integer.toString(keyInt) + "</decimal>");
        returnXML.append("\r\n<hexadecimal>0x" + Integer.toString(keyInt, 16) + "</hexadecimal>");
        returnXML.append("\r\n<octal>0" + Integer.toString(keyInt, 8) + "</octal>");
        returnXML.append("\r\n<hyper>&amp;0x" + Integer.toString(keyInt, 16) + ";</hyper>");
        returnXML.append("\r\n<binary>" + Integer.toString(keyInt, 2) + "B</binary>");
        returnXML.append("\r\n</converted-values>");
        return returnXML.toString();
    }

     public String createJdomXML(int key) throws IOException {
        Document document = new Document();
        // create root node
        Element root = new org.jdom.Element("converted-values");
        document.setRootElement(root);

        // create your a node
        org.jdom.Element element = new org.jdom.Element("decimal");
        // add content to the node
        element.addContent(Integer.toString(key));
        // add your node to root
        root.addContent(element);

        element = new org.jdom.Element("hexadecimal");
        element.addContent("0x" + Integer.toString(key, 16));
        root.addContent(element);
        element = new org.jdom.Element("octal");
        element.addContent("0" + Integer.toString(key, 8));
        root.addContent(element);
        element = new org.jdom.Element("hyper");
        element.addContent("&0x" + Integer.toString(key, 16));
        root.addContent(element);
        element = new org.jdom.Element("binary");
        element.addContent(Integer.toString(key, 2) + "B");
        root.addContent(element);

        // output JDOM document as a String of bytes
        XMLOutputter outputter = new XMLOutputter();
        return outputter.outputString(document);
    }
     
    public String createDom4jXML(int key) throws IOException {
        org.dom4j.Document document = org.dom4j.DocumentHelper.createDocument();
        org.dom4j.Element root = document.addElement("converted-values");

        org.dom4j.Element element = root.addElement("decimal").addText(
                Integer.toString(key));
        element = root.addElement("hexadecimal").addText(
                "0x" + Integer.toString(key, 16));
        element = root.addElement("octal").addText("0" + Integer.toString(key, 8));
        element = root.addElement("hyper").addText(
                "&0x" + Integer.toString(key, 16));
        element = root.addElement("binary").addText(Integer.toString(key, 2) + "B");
        StringBuffer xmlDoc = null;

        StringWriter sw = new StringWriter();
        org.dom4j.io.XMLWriter writer = new org.dom4j.io.XMLWriter(sw);
        writer.write(document);
        writer.close();
        xmlDoc = sw.getBuffer();

        return xmlDoc.toString();
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
    * Handles the HTTP <code>GET</code> method.
    * @param request servlet request
    * @param response servlet response
    */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    } 

    /** 
    * Handles the HTTP <code>POST</code> method.
    * @param request servlet request
    * @param response servlet response
    */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
    * Returns a short description of the servlet.
    */
    public String getServletInfo() {
        return "Short description";
    }
    // </editor-fold>
}