eu.nubomedia.tutorial.magicmirror.MagicMirrorHandler.java Source code

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Here is the source code for eu.nubomedia.tutorial.magicmirror.MagicMirrorHandler.java

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/*
 * (C) Copyright 2016 NUBOMEDIA (http://www.nubomedia.eu)
 *
 * 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 eu.nubomedia.tutorial.magicmirror;

import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;

import org.kurento.client.internal.NotEnoughResourcesException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.GsonBuilder;
import com.google.gson.JsonObject;

/**
 * Magic Mirror handler (application and media logic).
 *
 * @author Boni Garcia (boni.garcia@urjc.es)
 * @since 6.4.1
 */
public class MagicMirrorHandler extends TextWebSocketHandler {

    private final Logger log = LoggerFactory.getLogger(MagicMirrorHandler.class);

    private final ConcurrentHashMap<String, UserSession> users = new ConcurrentHashMap<>();

    @Override
    public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        try {
            JsonObject jsonMessage = new GsonBuilder().create().fromJson(message.getPayload(), JsonObject.class);

            log.info("Incoming message: {}", jsonMessage);

            switch (jsonMessage.get("id").getAsString()) {
            case "start":
                start(session, jsonMessage);
                break;
            case "stop": {
                release(session);
                break;
            }
            case "onIceCandidate": {
                onIceCandidate(session, jsonMessage);
                break;
            }
            default:
                error(session, "Invalid message with id " + jsonMessage.get("id").getAsString());
                break;
            }

        } catch (NotEnoughResourcesException e) {
            log.warn("Not enough resources", e);
            notEnoughResources(session);

        } catch (Throwable t) {
            log.error("Exception starting session", t);
            error(session, t.getClass().getSimpleName() + ": " + t.getMessage());
        }
    }

    private void start(final WebSocketSession session, JsonObject jsonMessage) {
        // User session
        String sessionId = session.getId();
        UserSession user = new UserSession(sessionId, this);
        users.put(sessionId, user);

        // Media logic for magic mirror
        String sdpOffer = jsonMessage.get("sdpOffer").getAsString();
        String sdpAnswer = user.startSession(session, sdpOffer);

        // Response message
        JsonObject response = new JsonObject();
        response.addProperty("id", "startResponse");
        response.addProperty("sdpAnswer", sdpAnswer);
        sendMessage(session, new TextMessage(response.toString()));
    }

    private void onIceCandidate(WebSocketSession session, JsonObject jsonMessage) {
        JsonObject jsonCandidate = jsonMessage.get("candidate").getAsJsonObject();
        UserSession user = users.get(session.getId());
        if (user != null) {
            user.addCandidate(jsonCandidate);
        }
    }

    private void notEnoughResources(WebSocketSession session) {
        // Send notEnoughResources message to client
        JsonObject response = new JsonObject();
        response.addProperty("id", "notEnoughResources");
        sendMessage(session, new TextMessage(response.toString()));

        // Release media session
        release(session);
    }

    private void error(WebSocketSession session, String message) {
        // Send error message to client
        JsonObject response = new JsonObject();
        response.addProperty("id", "error");
        response.addProperty("message", message);
        sendMessage(session, new TextMessage(response.toString()));

        // Release media session
        release(session);
    }

    private void release(WebSocketSession session) {
        UserSession user = users.remove(session.getId());
        if (user != null) {
            user.release();
        }
    }

    public synchronized void sendMessage(WebSocketSession session, TextMessage message) {
        try {
            log.info("Sending message {} in session {}", message.getPayload(), session.getId());
            session.sendMessage(message);

        } catch (IOException e) {
            log.error("Exception sending message", e);
        }
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        log.info("Closed websocket connection of session {}", session.getId());
        release(session);
    }
}