将对等组广告的内容打印到控制台

    public static void printPeerGroupAdvertisement(PeerGroup pg) throws IOException {
        Advertisement adv = pg.getPeerGroupAdvertisement();
        StructuredTextDocument doc = (StructuredTextDocument)adv.getDocument(MimeMediaType.TEXTUTF8);
        PrintWriter out = new PrintWriter(System.out);
        doc.sendToWriter(out);
        out.flush();
    }