public Room getRoom(String roomName) {log.debug("Searching for room {}", roomName);Room room = rooms.get(roomName);if (room == null) {log.debug("Room {} not existent. Will create now!", roomName);room = new Room(roomName, kurento.createMediaPipeline());rooms.put(roomName, room);}log.debug("Room {} found!", roomName);return room;}

    public UserSession(final String name, String roomName, final WebSocketSession session,MediaPipeline pipeline) {this.pipeline = pipeline;this.name = name;this.session = session;this.roomName = roomName;this.outgoingMedia = new WebRtcEndpoint.Builder(pipeline).build();this.outgoingMedia.addIceCandidateFoundListener(event -> {JsonObject response = new JsonObject();response.addProperty("id", "iceCandidate");response.addProperty("name", name);response.add("candidate", JsonUtils.toJsonObject(event.getCandidate()));try {synchronized (session) {session.sendMessage(new TextMessage(response.toString()));}} catch (IOException e) {log.debug(e.getMessage());}});}

    public UserSession join(String userName, WebSocketSession session) throws IOException {log.info("ROOM {}: adding participant {}", this.name, userName);final UserSession participant = new UserSession(userName, this.name, session, this.pipeline);//示例工程上，没考虑“相同用户名”的人进入同1个房间的情况，这里加上了“用户名重名”检测if (participants.containsKey(userName)) {final JsonObject jsonFailMsg = new JsonObject();final JsonArray jsonFailArray = new JsonArray();jsonFailArray.add(userName + " exist!");jsonFailMsg.addProperty("id", "joinFail");jsonFailMsg.add("data", jsonFailArray);participant.sendMessage(jsonFailMsg);participant.close();return null;}joinRoom(participant);participants.put(participant.getName(), participant);sendParticipantNames(participant);return participant;}

ws.onmessage = function (message) {let parsedMessage = JSON.parse(message.data);console.info('Received message: ' + message.data);switch (parsedMessage.id) {case 'existingParticipants':onExistingParticipants(parsedMessage);break;case 'newParticipantArrived':onNewParticipant(parsedMessage);break;case 'participantLeft':onParticipantLeft(parsedMessage);break;case 'receiveVideoAnswer':receiveVideoResponse(parsedMessage);break;case 'iceCandidate':participants[parsedMessage.name].rtcPeer.addIceCandidate(parsedMessage.candidate, function (error) {if (error) {console.error("Error adding candidate: " + error);return;}});break;case 'joinFail':alert(parsedMessage.data[0]);window.location.reload();break;default:console.error('Unrecognized message', parsedMessage);}
}

function onExistingParticipants(msg) {const constraints = {audio: true,video: {mandatory: {maxWidth: 320,maxFrameRate: 15,minFrameRate: 15}}};console.log(name + " registered in room " + room);let participant = new Participant(name);participants[name] = participant;let video = participant.getVideoElement();const options = {localVideo: video,mediaConstraints: constraints,onicecandidate: participant.onIceCandidate.bind(participant)};participant.rtcPeer = new kurentoUtils.WebRtcPeer.WebRtcPeerSendonly(options,function (error) {if (error) {return console.error(error);}this.generateOffer(participant.offerToReceiveVideo.bind(participant));});msg.data.forEach(receiveVideo);
}

    @Overridepublic void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {final JsonObject jsonMessage = gson.fromJson(message.getPayload(), JsonObject.class);final UserSession user = registry.getBySession(session);if (user != null) {log.debug("Incoming message from user '{}': {}", user.getName(), jsonMessage);} else {log.debug("Incoming message from new user: {}", jsonMessage);}switch (jsonMessage.get("id").getAsString()) {case "joinRoom":joinRoom(jsonMessage, session);break;case "receiveVideoFrom":final String senderName = jsonMessage.get("sender").getAsString();final UserSession sender = registry.getByName(senderName);final String sdpOffer = jsonMessage.get("sdpOffer").getAsString();user.receiveVideoFrom(sender, sdpOffer);break;case "leaveRoom":leaveRoom(user);break;case "onIceCandidate":JsonObject candidate = jsonMessage.get("candidate").getAsJsonObject();if (user != null) {IceCandidate cand = new IceCandidate(candidate.get("candidate").getAsString(),candidate.get("sdpMid").getAsString(), candidate.get("sdpMLineIndex").getAsInt());user.addCandidate(cand, jsonMessage.get("name").getAsString());}break;default:break;}}

    public void receiveVideoFrom(UserSession sender, String sdpOffer) throws IOException {log.info("USER {}: connecting with {} in room {}", this.name, sender.getName(), this.roomName);log.trace("USER {}: SdpOffer for {} is {}", this.name, sender.getName(), sdpOffer);final String ipSdpAnswer = this.getEndpointForUser(sender).processOffer(sdpOffer);final JsonObject scParams = new JsonObject();scParams.addProperty("id", "receiveVideoAnswer");scParams.addProperty("name", sender.getName());scParams.addProperty("sdpAnswer", ipSdpAnswer);log.trace("USER {}: SdpAnswer for {} is {}", this.name, sender.getName(), ipSdpAnswer);this.sendMessage(scParams);log.debug("gather candidates");this.getEndpointForUser(sender).gatherCandidates();}