Java tutorial
/* * (C) Copyright 2016 elasticRTC (https://www.elasticRTC.com/) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ package com.elasticrtc.tutorial.one2many.ws; import java.io.IOException; import java.util.concurrent.ConcurrentHashMap; import org.kurento.client.EventListener; import org.kurento.client.IceCandidate; import org.kurento.client.IceCandidateFoundEvent; import org.kurento.client.KurentoClient; import org.kurento.client.MediaPipeline; import org.kurento.client.WebRtcEndpoint; import org.kurento.jsonrpc.JsonUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.socket.CloseStatus; import org.springframework.web.socket.TextMessage; import org.springframework.web.socket.WebSocketSession; import org.springframework.web.socket.handler.TextWebSocketHandler; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonObject; /** * Protocol handler for 1 to N video call communication. * * @author Boni Garcia (bgarcia@gsyc.es) * @author Ivan Gracia (igracia@kurento.org) * @since 1.0.0 */ public class CallHandler extends TextWebSocketHandler { private static final Logger log = LoggerFactory.getLogger(CallHandler.class); private static final Gson gson = new GsonBuilder().create(); private final ConcurrentHashMap<String, UserSession> viewers = new ConcurrentHashMap<>(); @Autowired private KurentoClient kurento; private MediaPipeline pipeline; private UserSession presenterUserSession; @Override public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception { JsonObject jsonMessage = gson.fromJson(message.getPayload(), JsonObject.class); log.debug("Incoming message from session '{}': {}", session.getId(), jsonMessage); switch (jsonMessage.get("id").getAsString()) { case "presenter": try { presenter(session, jsonMessage); } catch (Throwable t) { handleErrorResponse(t, session, "presenterResponse"); } break; case "viewer": try { viewer(session, jsonMessage); } catch (Throwable t) { handleErrorResponse(t, session, "viewerResponse"); } break; case "onIceCandidate": { JsonObject candidate = jsonMessage.get("candidate").getAsJsonObject(); UserSession user = null; if (presenterUserSession != null) { if (presenterUserSession.getSession() == session) { user = presenterUserSession; } else { user = viewers.get(session.getId()); } } if (user != null) { IceCandidate cand = new IceCandidate(candidate.get("candidate").getAsString(), candidate.get("sdpMid").getAsString(), candidate.get("sdpMLineIndex").getAsInt()); user.addCandidate(cand); } break; } case "stop": stop(session); break; default: break; } } private void handleErrorResponse(Throwable throwable, WebSocketSession session, String responseId) throws IOException { stop(session); log.error(throwable.getMessage(), throwable); JsonObject response = new JsonObject(); response.addProperty("id", responseId); response.addProperty("response", "rejected"); response.addProperty("message", throwable.getMessage()); session.sendMessage(new TextMessage(response.toString())); } private synchronized void presenter(final WebSocketSession session, JsonObject jsonMessage) throws IOException { if (presenterUserSession == null) { presenterUserSession = new UserSession(session); pipeline = kurento.createMediaPipeline(); presenterUserSession.setWebRtcEndpoint(new WebRtcEndpoint.Builder(pipeline).build()); WebRtcEndpoint presenterWebRtc = presenterUserSession.getWebRtcEndpoint(); presenterWebRtc.addIceCandidateFoundListener(new EventListener<IceCandidateFoundEvent>() { @Override public void onEvent(IceCandidateFoundEvent event) { JsonObject response = new JsonObject(); response.addProperty("id", "iceCandidate"); response.add("candidate", JsonUtils.toJsonObject(event.getCandidate())); try { synchronized (session) { session.sendMessage(new TextMessage(response.toString())); } } catch (IOException e) { log.debug(e.getMessage()); } } }); String sdpOffer = jsonMessage.getAsJsonPrimitive("sdpOffer").getAsString(); String sdpAnswer = presenterWebRtc.processOffer(sdpOffer); JsonObject response = new JsonObject(); response.addProperty("id", "presenterResponse"); response.addProperty("response", "accepted"); response.addProperty("sdpAnswer", sdpAnswer); synchronized (session) { presenterUserSession.sendMessage(response); } presenterWebRtc.gatherCandidates(); } else { JsonObject response = new JsonObject(); response.addProperty("id", "presenterResponse"); response.addProperty("response", "rejected"); response.addProperty("message", "Another user is currently acting as sender. Try again later ..."); session.sendMessage(new TextMessage(response.toString())); } } private synchronized void viewer(final WebSocketSession session, JsonObject jsonMessage) throws IOException { if (presenterUserSession == null || presenterUserSession.getWebRtcEndpoint() == null) { JsonObject response = new JsonObject(); response.addProperty("id", "viewerResponse"); response.addProperty("response", "rejected"); response.addProperty("message", "No active sender now. Become sender or . Try again later ..."); session.sendMessage(new TextMessage(response.toString())); } else { if (viewers.containsKey(session.getId())) { JsonObject response = new JsonObject(); response.addProperty("id", "viewerResponse"); response.addProperty("response", "rejected"); response.addProperty("message", "You are already viewing in this session. " + "Use a different browser to add additional viewers."); session.sendMessage(new TextMessage(response.toString())); return; } UserSession viewer = new UserSession(session); viewers.put(session.getId(), viewer); WebRtcEndpoint nextWebRtc = new WebRtcEndpoint.Builder(pipeline).build(); nextWebRtc.addIceCandidateFoundListener(new EventListener<IceCandidateFoundEvent>() { @Override public void onEvent(IceCandidateFoundEvent event) { JsonObject response = new JsonObject(); response.addProperty("id", "iceCandidate"); response.add("candidate", JsonUtils.toJsonObject(event.getCandidate())); try { synchronized (session) { session.sendMessage(new TextMessage(response.toString())); } } catch (IOException e) { log.debug(e.getMessage()); } } }); viewer.setWebRtcEndpoint(nextWebRtc); presenterUserSession.getWebRtcEndpoint().connect(nextWebRtc); String sdpOffer = jsonMessage.getAsJsonPrimitive("sdpOffer").getAsString(); String sdpAnswer = nextWebRtc.processOffer(sdpOffer); JsonObject response = new JsonObject(); response.addProperty("id", "viewerResponse"); response.addProperty("response", "accepted"); response.addProperty("sdpAnswer", sdpAnswer); synchronized (session) { viewer.sendMessage(response); } nextWebRtc.gatherCandidates(); } } private synchronized void stop(WebSocketSession session) throws IOException { String sessionId = session.getId(); if (presenterUserSession != null && presenterUserSession.getSession().getId().equals(sessionId)) { for (UserSession viewer : viewers.values()) { JsonObject response = new JsonObject(); response.addProperty("id", "stopCommunication"); viewer.sendMessage(response); } log.info("Releasing media pipeline"); if (pipeline != null) { pipeline.release(); } pipeline = null; presenterUserSession = null; } else if (viewers.containsKey(sessionId)) { if (viewers.get(sessionId).getWebRtcEndpoint() != null) { viewers.get(sessionId).getWebRtcEndpoint().release(); } viewers.remove(sessionId); } } @Override public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception { stop(session); } }