/**
* Copyright (c) 2010-2014, openHAB.org and others.
*
* 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.openhab.binding.ntp.internal;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Dictionary;
import java.util.Locale;
import java.util.TimeZone;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.net.ntp.NTPUDPClient;
import org.apache.commons.net.ntp.TimeInfo;
import org.openhab.binding.ntp.NtpBindingProvider;
import org.openhab.core.binding.AbstractActiveBinding;
import org.openhab.core.library.types.DateTimeType;
import org.osgi.service.cm.ConfigurationException;
import org.osgi.service.cm.ManagedService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The NTP Refresh Service polls the configured timeserver with a configurable
* interval and posts a new event of type ({@link DateTimeType} to the event bus.
* The interval is 15 minutes by default and can be changed via openhab.cfg.
*
* @author Thomas.Eichstaedt-Engelen
* @since 0.8.0
*/
public class NtpBinding extends AbstractActiveBinding<NtpBindingProvider> implements ManagedService {
private static final Logger logger = LoggerFactory.getLogger(NtpBinding.class);
/** timeout for requests to the NTP server */
private static final int NTP_TIMEOUT = 5000;
// List of time servers: http://tf.nist.gov/service/time-servers.html
protected String hostname = "ptbtime1.ptb.de";
/** Default refresh interval (currently 15 minutes) */
private long refreshInterval = 900000L;
/** for logging purposes */
private final static DateFormat SDF =
SimpleDateFormat.getDateTimeInstance(SimpleDateFormat.FULL, SimpleDateFormat.FULL);
@Override
protected String getName() {
return "NTP Refresh Service";
}
@Override
protected long getRefreshInterval() {
return refreshInterval;
}
/**
* @{inheritDoc}
*/
@Override
public void execute() {
if (!bindingsExist()) {
logger.debug("There is no existing NTP binding configuration => refresh cycle aborted!");
return;
}
long networkTimeInMillis = getTime(hostname);
logger.debug("Got time from {}: {}", hostname, SDF.format(new Date(networkTimeInMillis)));
for (NtpBindingProvider provider : providers) {
for (String itemName : provider.getItemNames()) {
TimeZone timeZone = provider.getTimeZone(itemName);
Locale locale = provider.getLocale(itemName);
Calendar calendar = Calendar.getInstance(timeZone, locale);
calendar.setTimeInMillis(networkTimeInMillis);
eventPublisher.postUpdate(itemName, new DateTimeType(calendar));
}
}
}
/**
* Queries the given timeserver <code>hostname</code> and returns the time
* in milliseconds.
*
* @param hostname the timeserver to query
* @return the time in milliseconds or the current time of the system if an
* error occurs.
*/
protected static long getTime(String hostname) {
try {
NTPUDPClient timeClient = new NTPUDPClient();
timeClient.setDefaultTimeout(NTP_TIMEOUT);
InetAddress inetAddress = InetAddress.getByName(hostname);
TimeInfo timeInfo = timeClient.getTime(inetAddress);
return timeInfo.getReturnTime();
}
catch (UnknownHostException uhe) {
logger.warn("the given hostname '{}' of the timeserver is unknown -> returning current sytem time instead", hostname);
}
catch (IOException ioe) {
logger.warn("couldn't establish network connection [host '{}'] -> returning current sytem time instead", hostname);
}
return System.currentTimeMillis();
}
/**
* {@inheritDoc}
*/
@SuppressWarnings("rawtypes")
public void updated(Dictionary config) throws ConfigurationException {
if (config != null) {
String hostnameString = (String) config.get("hostname");
if (StringUtils.isNotBlank(hostnameString)) {
hostname = hostnameString;
}
String refreshIntervalString = (String) config.get("refresh");
if (StringUtils.isNotBlank(refreshIntervalString)) {
refreshInterval = Long.parseLong(refreshIntervalString);
}
setProperlyConfigured(true);
}
}
}