MDNSServiceImpl.java

/**
 * Copyright (c) 2014-2017 by the respective copyright holders.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.eclipse.smarthome.io.transport.mdns.internal;

import java.io.IOException;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.Executors;

import org.eclipse.smarthome.io.transport.mdns.MDNSClient;
import org.eclipse.smarthome.io.transport.mdns.MDNSService;
import org.eclipse.smarthome.io.transport.mdns.ServiceDescription;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This class starts the JmDNS and implements interface to register and
 * unregister services.
 *
 * @author Victor Belov
 *
 */
public class MDNSServiceImpl implements MDNSService {

    private final Logger logger = LoggerFactory.getLogger(MDNSServiceImpl.class);
    private MDNSClient mdnsClient;

    private Set<ServiceDescription> servicesToRegisterQueue = new CopyOnWriteArraySet<>();

    public MDNSServiceImpl() {
    }

    public void setMDNSClient(MDNSClient client) {
        this.mdnsClient = client;
        // register queued services
        if (servicesToRegisterQueue.size() > 0) {
            Runnable runnable = new Runnable() {
                @Override
                public void run() {
                    logger.debug("Registering {} queued services", servicesToRegisterQueue.size());
                    for (ServiceDescription description : servicesToRegisterQueue) {
                        try {
                            MDNSClient localClient = mdnsClient;
                            if (localClient != null) {
                                localClient.registerService(description);
                            } else {
                                break;
                            }
                        } catch (IOException e) {
                            logger.error(e.getMessage());
                        } catch (IllegalStateException e) {
                            logger.debug("Not registering service {}, because service is already deactivated!",
                                    description.serviceType);
                        }
                    }
                    servicesToRegisterQueue.clear();
                }
            };
            Executors.newSingleThreadExecutor().execute(runnable);
        }
    }

    public void unsetMDNSClient(MDNSClient mdnsClient) {
        this.mdnsClient = null;
        mdnsClient.unregisterAllServices();
    }

    /**
     * @{inheritDoc
     */
    @Override
    public void registerService(final ServiceDescription description) {
        if (mdnsClient == null) {
            // queue the service to register it as soon as the mDNS client is
            // available
            servicesToRegisterQueue.add(description);
        } else {
            Runnable runnable = new Runnable() {
                @Override
                public void run() {
                    try {
                        mdnsClient.registerService(description);
                    } catch (IOException e) {
                        logger.error(e.getMessage());
                    } catch (IllegalStateException e) {
                        logger.debug("Not registering service {}, because service is already deactivated!",
                                description.serviceType);
                    }
                }
            };
            Executors.newSingleThreadExecutor().execute(runnable);
        }
    }

    /**
     * @{inheritDoc
     */
    @Override
    public void unregisterService(ServiceDescription description) {
        if (mdnsClient != null) {
            mdnsClient.unregisterService(description);
        }
    }

    /**
     * This method unregisters all services from Bonjour/MDNS
     */
    protected void unregisterAllServices() {
        if (mdnsClient != null) {
            mdnsClient.unregisterAllServices();
        }
    }

    public void activate() {

    }

    public void deactivate() {
        unregisterAllServices();
        if (mdnsClient != null) {
            mdnsClient.close();
            logger.debug("mDNS service has been stopped");
        }
    }

}