/*
* This file is part of muCommander, http://www.mucommander.com
* Copyright (C) 2002-2016 Maxence Bernard
*
* muCommander is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* muCommander is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.mucommander.bonjour;
import java.io.IOException;
import java.net.Inet6Address;
import java.net.MalformedURLException;
import java.util.List;
import java.util.Vector;
import javax.jmdns.JmDNS;
import javax.jmdns.ServiceEvent;
import javax.jmdns.ServiceInfo;
import javax.jmdns.ServiceListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.mucommander.commons.file.FileURL;
import com.mucommander.commons.file.protocol.FileProtocols;
/**
* Collects and maintains a list of available Bonjour/Zeroconf services using the JmDNS library.
* Newly discovered services are added to the list and removed as they become unavailable.
*
* <p>Use {@link #getServices()} to get a list of currently available Bonjour services.
*
* @author Maxence Bernard
* @see BonjourMenu
*/
public class BonjourDirectory implements ServiceListener {
private static final Logger LOGGER = LoggerFactory.getLogger(BonjourDirectory.class);
/** Singleton instance held to prevent garbage collection and also used for synchronization */
private final static BonjourDirectory instance = new BonjourDirectory();
/** Does all the hard work */
private static JmDNS jmDNS;
/** List of discovered and currently active Bonjour services */
private static List<BonjourService> services = new Vector<BonjourService>();
/** Known Bonjour/Zeroconf service types and their corresponding protocol */
private final static String KNOWN_SERVICE_TYPES[][] = {
{"_http._tcp.local.", FileProtocols.HTTP},
{"_ftp._tcp.local.", FileProtocols.FTP},
{"_ssh._tcp.local.", FileProtocols.SFTP},
{"_smb._tcp.local.", FileProtocols.SMB}
};
/** Number of milliseconds to wait for service info resolution before giving up */
private final static int SERVICE_RESOLUTION_TIMEOUT = 10000;
/**
* No-arg contructor made private so that only one instance can exist.
*/
private BonjourDirectory() {
}
/**
* Enables/disables Bonjour services discovery. If currently active and false is specified, current services
* will be lost and {@link #getServices()} will return an empty array. If currently inactive and true is specified,
* services discovery will be immediately started but it may take a while (a few seconds at least) to
* collect services.
* @param enabled whether Bonjour services discovery should be enabled.
*/
public static void setActive(boolean enabled) {
if(enabled && jmDNS==null) {
// Start JmDNS
try {
jmDNS = JmDNS.create();
// Listens to service events for known service types
int nbServices = KNOWN_SERVICE_TYPES.length;
for(int i=0; i<nbServices; i++)
jmDNS.addServiceListener(KNOWN_SERVICE_TYPES[i][0], instance);
}
catch(IOException e) {
LOGGER.warn("Could not instantiate jmDNS, Bonjour not enabled", e);
}
}
else if(!enabled && jmDNS!=null) {
// Shutdown JmDNS
try {
jmDNS.close();
} catch (IOException e) {
LOGGER.trace("Could not close jmDNS", e);
}
services.clear();
jmDNS = null;
}
}
/**
* Returns <code>true</code> if Bonjour services discovery is currently running.
* @return <code>true</code> if Bonjour services discovery is currently running, <code>false</code> otherwise.
*/
public static boolean isActive() {
return jmDNS!=null;
}
/**
* Returns all currently available Bonjour services. The returned array may be empty but never null.
* If BonjourDirectory is not currently active ({@link #isActive()}, an empty array will be returned.
* @return all currently available Bonjour services
*/
public static BonjourService[] getServices() {
BonjourService servicesArray[] = new BonjourService[services.size()];
services.toArray(servicesArray);
return servicesArray;
}
/**
* Wraps a Bonjour service into a {@link BonjourService} object and returns it. Returns <code>null</code> if
* the service type doesn't correspond to any of the supported protocols, or if the service URL is malformed.
*
* @param serviceInfo the ServiceInfo to wrap into a BonjourService
* @return a BonjourService instance corresponding to the given ServiceInfo
*/
private static BonjourService createBonjourService(ServiceInfo serviceInfo) {
try {
String type = serviceInfo.getType();
int nbServices = KNOWN_SERVICE_TYPES.length;
// Looks for the file protocol corresponding to the service type
for(int i=0; i<nbServices; i++) {
if(KNOWN_SERVICE_TYPES[i][0].equals(type)) {
return new BonjourService(serviceInfo.getName(), FileURL.getFileURL(serviceInfo.getURL(KNOWN_SERVICE_TYPES[i][1])), serviceInfo.getQualifiedName());
}
}
}
catch(MalformedURLException e) {
// Null will be returned
}
return null;
}
////////////////////////////////////
// ServiceListener implementation //
////////////////////////////////////
public void serviceAdded(final ServiceEvent serviceEvent) {
LOGGER.trace("name="+serviceEvent.getName()+" type="+serviceEvent.getType());
// Ignore if Bonjour has been disabled
if(!isActive())
return;
// Resolve service info in a separate thread, serviceResolved() will be called once service info has been resolved.
// Not spawning a thread often leads to service info loss (serviceResolved() not called).
new Thread() {
@Override
public void run() {
jmDNS.requestServiceInfo(serviceEvent.getType(), serviceEvent.getName(), SERVICE_RESOLUTION_TIMEOUT);
}
}.start();
}
public void serviceResolved(ServiceEvent serviceEvent) {
LOGGER.trace("name="+serviceEvent.getName()+" type="+serviceEvent.getType()+" info="+serviceEvent.getInfo());
// Ignore if Bonjour has been disabled
if(!isActive())
return;
// Creates a new BonjourService corresponding to the new service and add it to the list of current Bonjour services
ServiceInfo serviceInfo = serviceEvent.getInfo();
if(serviceInfo!=null) {
if(serviceInfo.getInetAddress() instanceof Inet6Address) {
// IPv6 addresses not supported at this time + they seem not to be correctly handled by ServiceInfo
LOGGER.debug("ignoring IPv6 service");
return;
}
BonjourService bs = createBonjourService(serviceInfo);
// Synchronized to properly handle duplicate calls
synchronized(instance) {
if(bs!=null && !services.contains(bs)) {
LOGGER.debug("BonjourService "+bs+" added");
services.add(bs);
}
}
}
}
public void serviceRemoved(ServiceEvent serviceEvent) {
LOGGER.trace("name="+serviceEvent.getName()+" type="+serviceEvent.getType());
// Ignore if Bonjour has been disabled
if(!isActive())
return;
// Looks for an existing BonjourService instance corresponding to the service being removed and removes it from
// the list of current Bonjour services.
// ServiceInfo should be available in JmDNS's cache.
ServiceInfo serviceInfo = jmDNS.getServiceInfo(serviceEvent.getType(), serviceEvent.getName());
if(serviceInfo!=null) {
if(serviceInfo.getInetAddress() instanceof Inet6Address) {
// IPv6 addresses not supported at this time + they seem not to be correctly handled by ServiceInfo
LOGGER.debug("ignoring IPv6 service");
return;
}
BonjourService bs = createBonjourService(serviceInfo);
// Synchronized to properly handle duplicate calls
synchronized(instance) {
// Note: BonjourService#equals() uses the service's fully qualified name as the discriminator.
if(bs!=null && services.contains(bs)) {
LOGGER.debug("BonjourService "+bs+" removed");
services.remove(bs);
}
}
}
}
}