使用JavaScript动态刷新页面局部内容 (2)

public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        System.out.println("begin");
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
        PrintWriter pw = response.getWriter();
        StringBuffer buf = new StringBuffer();
        for(int i = 0; i < 7; i++)
        {
            int status = (int)(Math.random() * 2);
            buf.append("" + status );
        }
        System.out.println("message:\n" + buf.toString() + "\n");
        pw.write(buf.toString());
        pw.flush();
        System.out.println("end");
    }

web.xml配置：