chat.java

老外写的chat

		print("Starting Rendezvous...");
		netRendezVousService.startRendezVous();
		print("done!\n");
	    }
	    else {
		print("Waiting to connect to Rendezvous..");
		while(!netRendezVousService.isConnectedToRendezVous()) {
		    print(".");
		    try {
			Thread.sleep(2 * 1000);
		    }
		    catch(InterruptedException e) {
		    }
		}
		print("connected!\n");
	    }
	    netDiscoveryService.addDiscoveryListener(this);
	    uninitialized = false;
	    isInitializing = false;
	}
	catch(net.jxta.exception.PeerGroupException e) {
	    System.out.println("fatal error : group creation failure");
	    e.printStackTrace();
	    System.exit(-1);
	}
	catch(Exception e) {
	    System.out.println("unknown error type : occured during group creation");
	    e.printStackTrace();
	    System.exit(-1);
	}
    }

    public synchronized void run()
    {
	int count;
	java.util.Enumeration j, k;
	HandledGroup handledG;
	HandledPipe handledP;
	Joined handledJ;
	try {
	    while(true) {
		if((Groups.size() == 0) && (handling.size() == 0) && (pipes.size() == 0)) return;
		// As long as there are groups to join or create,
		// pipes to look for or create,
		// or groups to promote
		j = handling.elements();
		while(j.hasMoreElements()) { // Traverse the groups that are to be handled
		    handledG = (HandledGroup)j.nextElement();
		    if(handledG.Counter < 6)
			// The group has been looked up less than 6 times,
			// i.e. for less than a minute.
			netDiscoveryService.getRemoteAdvertisements // Try again
			    (null,
			     net.jxta.discovery.DiscoveryService.GROUP,
			     "Name",
			     "Chat." + handledG.GroupName,
			     5);
		    else if(handledG.creating) {  // The group can safely be created
			print("  Creating group " + handledG.GroupName + "...");
			net.jxta.peergroup.PeerGroup grp;
			net.jxta.protocol.PeerGroupAdvertisement adv;
			try {
			    net.jxta.protocol.ModuleImplAdvertisement implAdv =
				netPeerGroup.getAllPurposePeerGroupImplAdvertisement();
			    grp = netPeerGroup.newGroup(null,
							implAdv,
							"Chat." + handledG.GroupName,
							"Chat group");
			    adv = grp.getPeerGroupAdvertisement();
			    print("done!\n");
			}
			catch(Exception e) {
			    print("\nGroup creation failed with " + e.toString() + '\n');
			    continue;
			}
			try {
			    print("Publishing group...");
			    netDiscoveryService.remotePublish(adv, netDiscoveryService.GROUP);
			    print("done!\n");
			}
			catch(Exception e) {
			    print("\nError publishing group advertisement\n");
			    e.printStackTrace();
			    continue;
			}
			print("Joining " + handledG.GroupName + "...");
			net.jxta.document.StructuredDocument creds = null;
			try {
			    net.jxta.credential.AuthenticationCredential authCred =
				new net.jxta.credential.AuthenticationCredential(grp,
										 null,
										 creds);
			    net.jxta.membership.MembershipService membership =
				grp.getMembershipService();
			    net.jxta.membership.Authenticator auth =
				membership.apply(authCred);
			    if(auth.isReadyForJoin()) {
				net.jxta.credential.Credential myCred =
				    membership.join(auth);
				print("joined!\n");
				Groups.put(handledG.GroupName,
					   new Joined(grp,
						      handledG.UserName,
						      handledG.Listener,
						      adv));
				print("Looking for group pipe.\n");
				pipes.put(handledG.GroupName,
					  new HandledPipe(handledG.GroupName));
				if(!runner.isAlive()) runner.start();
			    }
			    else print("\nFailure: unable to join group\n");
			}
			catch(Exception e) {
			    print("\nFailure in authentication.\n");
			    e.printStackTrace();
			}
			handling.remove(handledG.GroupName);
		    }
		    else {
			// The group has been looked up 6 times or more,
			// i.e. for more than a minute
			// We don't expect to find it, so we stop looking
			handledG.creating = true;
			print("Failure joining " +
			      handledG.GroupName +
			      " : Group not found.\nTrying to create group\n");
		    }
		    ++handledG.Counter;
		}
		j = pipes.elements();
		while(j.hasMoreElements()) { // Traverse the pipes that are to be handled
		    handledP = (HandledPipe)j.nextElement();
		    if(handledP.Counter < 4)
			// The pipe has been looked up less than 4 times,
			// i.e. for less than 40 seconds.
			netDiscoveryService.getRemoteAdvertisements // Try again
			    (null,
			     netDiscoveryService.ADV,
			     "Name",
			     "Chat.pipe." + handledP.GroupName,
			     5);
		    else if(handledP.Counter > 4) {
			// The group has been looked up 4 times or more,
			// i.e. for more than 40 seconds
			// so we assume it doen't exist and create it
			print("Pipe not found for group " +
			      handledP.GroupName +
			      ". Creating pipe...");
			Joined group = (Joined)Groups.get(handledP.GroupName);
			net.jxta.protocol.PipeAdvertisement adv =
			    (net.jxta.protocol.PipeAdvertisement)
			    net.jxta.document.AdvertisementFactory.newAdvertisement
			    (net.jxta.protocol.PipeAdvertisement.getAdvertisementType());
			adv.setPipeID(net.jxta.id.IDFactory.newPipeID
				      (group.netPeerGroup.getPeerGroupID()));
			adv.setName("Chat.pipe." + handledP.GroupName);
			adv.setType(netPipeService.PropagateType);
			try {
			    group.netInPipe = netPipeService.createInputPipe(adv, group);
			    group.netOutPipe = netPipeService.createOutputPipe(adv, -1);
			    print("done!\n");
			}
			catch(Exception e) {
			    print("\nPipe creation failed with " + e.toString() + '\n');
			    continue;
			}
			try {
			    print("Publishing pipe...");
			    netDiscoveryService.remotePublish(adv, netDiscoveryService.ADV);
			    print("done!\n");
			}
			catch(Exception e) {
			    print("\nError publishing pipe advertisement\n");
			    e.printStackTrace();
			    continue;
			}
			pipes.remove(handledP.GroupName);
		    }
		    ++handledP.Counter;
		}
		j = Groups.elements();
		while(j.hasMoreElements()) {
		    handledJ = (Joined)j.nextElement();
		    netDiscoveryService.remotePublish(handledJ.netAdvertisement,
						      netDiscoveryService.GROUP);
		}
		try {
		    Thread.sleep(10 * 1000); // Wait 10 seconds before trying again
		}
		catch(Exception e) {
		}
	    }
	}
	catch(Exception e) {
	    e.printStackTrace();
	}
    }
    
    public void discoveryEvent(net.jxta.discovery.DiscoveryEvent event)
    {
	while(isHandling);
	isHandling = true;
	net.jxta.protocol.DiscoveryResponseMsg res = event.getResponse();
	// We got a response to a lookup
	String name = "unknown";
	net.jxta.protocol.PeerAdvertisement peerAdv = res.getPeerAdvertisement();
	if(peerAdv != null) {
	    name = peerAdv.getName();
	}
	net.jxta.document.Advertisement adv = null;
	net.jxta.protocol.PeerGroupAdvertisement pgadv = null;
	net.jxta.protocol.PipeAdvertisement padv = null;
	java.util.Enumeration enum = res.getAdvertisements();
	net.jxta.peergroup.PeerGroup grp;
	if(enum != null) {
	    while(enum.hasMoreElements()) {
		adv = (net.jxta.document.Advertisement)enum.nextElement();
		if(adv.getAdvType().compareTo
		   (net.jxta.protocol.PeerGroupAdvertisement.getAdvertisementType()) == 0) {
		    // It was a peer group response
		    pgadv = (net.jxta.protocol.PeerGroupAdvertisement)adv;
		    String GroupName = pgadv.getName().substring(5);
		    HandledGroup handled = (HandledGroup)handling.get(GroupName);
		    if(handled != null) {
			if(handled.creating)
			    print("Cannot create group " + GroupName + " : it already exists.\n");
			print("Joining " + GroupName + "...");
			net.jxta.peergroup.PeerGroupID GID = pgadv.getPeerGroupID();
			try {
			    grp = netPeerGroup.newGroup(GID);
			}
			catch(Exception e) {
			    print("\nGroup creation failed with " + e.toString() + '\n');
			    continue;
			}
			net.jxta.document.StructuredDocument creds = null;
			try {
			    net.jxta.credential.AuthenticationCredential authCred =
				new net.jxta.credential.AuthenticationCredential(grp,
										 null,
										 creds);
			    net.jxta.membership.MembershipService membership =
				grp.getMembershipService();
			    net.jxta.membership.Authenticator auth =
				membership.apply(authCred);
			    if(auth.isReadyForJoin()) {
				net.jxta.credential.Credential myCred =
				    membership.join(auth);
				print("joined!\n");
				Groups.put(handled.GroupName,
					   new Joined(grp,
						      handled.UserName,
						      handled.Listener,
						      pgadv));
				print("Looking for group pipe.\n");
				pipes.put(handled.GroupName,
					  new HandledPipe(handled.GroupName));
				if(!runner.isAlive()) runner.start();
			    }
			    else print("\nFailure: unable to join group\n");
			}
			catch(Exception e) {
			    print("\nFailure in authentication.\n");
			    e.printStackTrace();
			}
			handling.remove(GroupName);
		    }
		}
		else if(adv.getAdvType().compareTo
			(net.jxta.protocol.PipeAdvertisement.getAdvertisementType()) == 0) {
		    padv = (net.jxta.protocol.PipeAdvertisement)adv;
		    String GroupName = padv.getName().substring(10);
		    Joined group = (Joined)Groups.get(GroupName);
		    if((group != null) && (group.netOutPipe == null)) {
			try {
			    print("Connecting to pipe to group " + GroupName + "...");
			    group.netInPipe = netPipeService.createInputPipe(padv, group);
			    group.netOutPipe = netPipeService.createOutputPipe(padv, -1);
			    print("done!\n");
			}
			catch(Exception e) {
			    print("\nPipe creation failed with " + e.toString() + '\n');
			    continue;
			}
			try {
			    print("Informing group members...");
			    net.jxta.endpoint.Message msg = new net.jxta.endpoint.Message();
			    net.jxta.endpoint.StringMessageElement sme =
				new net.jxta.endpoint.StringMessageElement("msg",
									   group.UserName +
									   " has joined.",
									   null);
			    msg.addMessageElement(null, sme);
			    group.netOutPipe.send(msg);
			}
			catch(Exception e) {
			    print("\nFailed to inform group members\n");
			    e.printStackTrace();
			    continue;
			}
			print("done!\n");
		    }
		    pipes.remove(GroupName);
		}
		else print("Received unhandled advertisement type: " + adv.getAdvType() + '\n');
	    }
	}
	isHandling = false;
    }
}