public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        PrintWriter printWriter = response.getWriter();
        response.setHeader("Content-Type", "text/xml ; charset=utf-8");
        response.setContentType("text/xml ; charset=utf-8");
        response.setCharacterEncoding("text/xml ; charset=utf-8");
    
        Document  document =DocumentHelper.createDocument();       
        Element rootElement = document.addElement("person");       
      count++;
      Element messagElement = rootElement.addElement("message");
      String str ="登录用户名"+name+"在线人数："+count;
      byte[] bytes = str.getBytes("utf-8");
      String returnstring = new String(bytes,0,bytes.length,"utf-8");
      System.out.println(returnstring);
      messagElement.setText(returnstring);
        OutputFormat format = OutputFormat.createCompactFormat();
        format.setEncoding("utf-8");
        
        XMLWriter xmlWriter = new XMLWriter(printWriter,format);
        
        xmlWriter.write(document);
        printWriter.flush();