java.io.IOException: Server returned HTTP response code: 403 for URL

I want to download the mp3 file from url : "http://upload13.music.qzone.soso.com/30671794.mp3", i always got java.io.IOException: Server returned HTTP response code: 403 for URL. But it's ok when open the url using browser. Below is part of my code:

BufferedInputStream bis = null;
BufferedOutputStream bos = null;
try {
    URL url = new URL(link);

    URLConnection urlConn = url.openConnection();
    urlConn.addRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)");

    String contentType = urlConn.getContentType();

    System.out.println("contentType:" + contentType);

    InputStream is = urlConn.getInputStream();
    bis = new BufferedInputStream(is, 4 * 1024);
    bos = new BufferedOutputStream(new FileOutputStream(
    fileName.toString()));​

Anyone could help me? Thanks in advance!