jailgameclient.java

Java P2P技术内幕：《Java P2P技术内幕》源码

            Thread.sleep(5 * 1000);
        } catch (Exception ignore) {}
        // Check to make sure the peer exists.
        Iterator iterator = jailPeerSet.iterator();
        boolean peerExists = false;
        // Find the peer's PeerAdvertisement
        while (iterator.hasNext()) {
            PeerAdvertisement adv = (PeerAdvertisement) iterator.next();
            if (adv.getName().equals(peerName)) {
                peerExists = true;
                break;
            }
        }
        String msg = (!peerExists) ? 
            "Warning:  Peer " + peerName + " may not exist.\n" +
            "Attempting to transfer anyways." : 
            "Transfering key to peer: " + peerName;
        System.out.println(msg);

        DiscoveryService jailDiscoverySvc = 
            jailPeerGroup.getDiscoveryService();
        DiscoveryListener listener = new DiscoveryListener() {
                /**
                 * Creates the output pipe that connects to the peer we wish
                 * to send the jail token to.  Then sends the jail token via
                 * the "key" element.
                 */
                public void discoveryEvent(DiscoveryEvent ev)
                {

                    DiscoveryResponseMsg res = ev.getResponse();
                    Enumeration enum = res.getResponses();
                    while (enum.hasMoreElements()) {
                        String advString = (String) enum.nextElement();
                        OutputPipe outputPipe = null;
                        try {
                            PipeAdvertisement pipeAdv = (PipeAdvertisement)
                                AdvertisementFactory.newAdvertisement(new MimeMediaType("text/xml"), new ByteArrayInputStream (advString.getBytes()));
                            PipeService pipeSvc = jailPeerGroup.getPipeService();
                            outputPipe = pipeSvc.createOutputPipe(pipeAdv, 1000);
                            // Create the actual message with the key and sender
                            Message message = pipeSvc.createMessage();
                            MessageElement messageElement = message.newMessageElement("key", new MimeMediaType("text/plain"), new ByteArrayInputStream(jailTokenString.getBytes()));
                            message.addElement(messageElement);
                            MessageElement senderElement = message.newMessageElement("sender", new MimeMediaType("text/plain"), new ByteArrayInputStream(jailPeerGroup.getPeerName().getBytes()));
                            message.addElement(senderElement);
                            outputPipe.send(message);
                            JailGameClient.this.hasJailToken = false;
                            return;
                        } catch (Exception e) {
                            e.printStackTrace();
                        } finally {
                            if (outputPipe != null) {
                                outputPipe.close();
                            }
                        }

                    }
                }
            };
        String name = JailGameClient.JAIL_TRANSFER_KEY + ":" + peerName;
        jailDiscoverySvc.getRemoteAdvertisements(null, DiscoveryService.ADV,
                                                 "name", name, 10, listener);
        // Now sleep for the transfer to finish
        try {
            Thread.sleep(10 * 1000); // we may want to sleep longer
        } catch (Exception ignore) { }

        return !this.hasJailToken;

    }

    /**
     * This method is used to clean up all the resources so we can start from scratch.
     */
    private void cleanResources()
    {
        this.inputUnicastPipe.close();
        this.unicastListener = null;

        this.jailPeerSet.clear();
        this.groupFound = false;
        this.inJail = false;
        this.pipeAdvFound = false;
        this.hasJailToken = false;
        this.jailTokenString = null;
        ResolverService resolverSvc = this.jailPeerGroup.getResolverService();
        resolverSvc.unregisterHandler(JailGameClient.JAIL_KEY_QUERY_HANDLER);
        resolverSvc.unregisterHandler(JailGameClient.JAIL_KEY_LOCATOR_HANDLER);
        this.jailPeerGroup = null;
    }

    /**
     * A utility method to print out the contents of an advertisement.
     */
    public static void printAdvertisement(Advertisement adv)
    {
        try {
            Document doc = adv.getDocument(new MimeMediaType("text/plain"));
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            doc.sendToStream(output);
            System.out.println(output.toString());


//             BufferedInputStream stream = new BufferedInputStream(doc.getStream());
//             StringBuffer buffer = new StringBuffer();
//             byte [] bytes = new byte[stream.available()];
//             while ((c = stream.readChar())!= null) {
//                 buffer.append(c);
//             }
//             System.out.println(buffer.toString());
        } catch (Exception ignore) {
            ignore.printStackTrace();
        }
    }

    /**
     * Start up the Net Peer group & get the Discovery Service for that group.
     */
    public void startJxta()
        throws PeerGroupException, IOException
    {
        this.netPeerGroup = PeerGroupFactory.newNetPeerGroup();
        this.discoverySvc = netPeerGroup.getDiscoveryService();
        // Flush all local cache information.  We want to start from scratch.
        discoverySvc.flushAdvertisements(null, DiscoveryService.ADV);
        discoverySvc.flushAdvertisements(null, DiscoveryService.PEER);
        discoverySvc.flushAdvertisements(null, DiscoveryService.GROUP);
    }

    public void run()
    {
        try {
            if (createOrJoin == JailGameClient.JOIN_GAME) {

                discoverJailGroup();

            } else { // Create the group.  Add a propagate PIPE Advertisement to it.

                jailPeerGroup = createGroup(JailGameClient.JAIL_GROUP);
                this.hasJailToken = true;
                // the token is just the current time :)
                this.jailTokenString = "" + System.currentTimeMillis();

                publish(jailPeerGroup.getPeerGroupAdvertisement(),
                        DiscoveryService.GROUP);
            }
            // Publish the unicast pipe used to send the jail token to others.
            createJailUnicastPipeAdv();
            publishJailAdv(jailUnicastPipeAdv, DiscoveryService.ADV);

            // Start the RendezVousService
            //netPeerGroup.getRendezVousService().startRendezVous();
            //jailPeerGroup.getRendezVousService().startRendezVous();

        } catch (Exception e) {
            String errMsg = "Unable to start create or join jail group.";
            System.out.println(errMsg);
            e.printStackTrace();
            
            return;
        }
        if (!joinPeerGroup(jailPeerGroup)) {
            return;
        }
        
        try {
            this.createPipes();
        } catch (Exception ex) {
            String errMsg = "Unable to create broadcast pipes";
            System.out.println(errMsg);
            ex.printStackTrace();
            return;
        }
        setResolverHandler();
        
        // This is the user interface menu.
        for (;;) {
            BufferedReader reader =
                new BufferedReader(new InputStreamReader(System.in));
            String lineToSend = null;
            System.out.print("Type H for help\n:>");
            try {
                while ((lineToSend = reader.readLine()) != null) {
                    lineToSend = lineToSend.trim();

                    if (lineToSend.equals("")) {
                        System.out.print(":>");
                        continue;
                    }

                    if (!inJail && !lineToSend.equalsIgnoreCase("Q")) {
                        System.out.println("You are not in jail.  You can only quit");
                        System.out.print(":>");
                        continue;
                    }

                    StringTokenizer tokenizer =
                        new StringTokenizer(lineToSend);
                    String command = tokenizer.nextToken();

                    if (command.equalsIgnoreCase("L")) {
                        if (!tokenizer.hasMoreTokens()) {
                            System.out.println("Peer name missing");
                        } else {
                            String peerName = tokenizer.nextToken();
                            leaveJail(peerName);
                        }
                    } else if (command.equalsIgnoreCase("R")) {
                        requestJailToken();
                    } else if (command.equalsIgnoreCase("P")) {
                        printPeers();
                    } else if (command.equalsIgnoreCase("F")) {
                        findJailToken();
                    } else if (command.equalsIgnoreCase("T")) {
                        if (!tokenizer.hasMoreTokens()) {
                            System.out.println("Client name missing");
                        } else {
                            String peerName = tokenizer.nextToken();
                            transferJailKey(peerName);
                        }

                    } else if (command.equalsIgnoreCase("H")) {
                        printHelp();
                    } else if (command.equalsIgnoreCase("Q")) {
                        quit();
                    }

                
                    System.out.print(":>");
                }
            } catch (Exception io) {
                io.printStackTrace();
            }
        }

    }

    public void printHelp()
    {
        String help = "H - print this help\nF - find who has the token\nR - request jail token\nP - print peers\nT <client> - transfer jail token to client\nL <client> - leave jail and send jail token to client\nQ - quit application\n";
        System.out.println(help);
    }

    public static void main (String argc[])
        throws Exception
    {
        if (argc.length < 1) {
            String msg = "Usage: " + JailGameClient.class.getName()
                + " [join/create]";
            System.out.println(msg);
            return;
        }
        int createOrJoin = (argc[0].equals("join")) ?
            JailGameClient.JOIN_GAME : JailGameClient.CREATE_GAME ;

        JailGameClient client = new JailGameClient(createOrJoin);
        client.startJxta();
        Thread thread = new Thread(client);
        thread.start();
    }

}