michael@0: /**
michael@0:  * Copyright (c) 2012, Ben Fortuna
michael@0:  * All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  *  o Redistributions of source code must retain the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer.
michael@0:  *
michael@0:  *  o Redistributions in binary form must reproduce the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer in the
michael@0:  * documentation and/or other materials provided with the distribution.
michael@0:  *
michael@0:  *  o Neither the name of Ben Fortuna nor the names of any other contributors
michael@0:  * may be used to endorse or promote products derived from this software
michael@0:  * without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0:  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
michael@0:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
michael@0:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
michael@0:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
michael@0:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
michael@0:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
michael@0:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
michael@0:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: package net.fortuna.ical4j.model;
michael@0: 
michael@0: import java.io.IOException;
michael@0: import java.net.URL;
michael@0: import java.util.Map;
michael@0: import java.util.Properties;
michael@0: import java.util.regex.Matcher;
michael@0: import java.util.regex.Pattern;
michael@0: 
michael@0: import net.fortuna.ical4j.data.CalendarBuilder;
michael@0: import net.fortuna.ical4j.data.ParserException;
michael@0: import net.fortuna.ical4j.model.component.VTimeZone;
michael@0: import net.fortuna.ical4j.model.property.TzUrl;
michael@0: import net.fortuna.ical4j.util.CompatibilityHints;
michael@0: import net.fortuna.ical4j.util.Configurator;
michael@0: import net.fortuna.ical4j.util.ResourceLoader;
michael@0: 
michael@0: import org.apache.commons.logging.Log;
michael@0: import org.apache.commons.logging.LogFactory;
michael@0: 
michael@0: import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap;
michael@0: 
michael@0: /**
michael@0:  * $Id$
michael@0:  *
michael@0:  * Created on 18/09/2005
michael@0:  *
michael@0:  * The default implementation of a <code>TimeZoneRegistry</code>. This implementation will search the classpath for
michael@0:  * applicable VTimeZone definitions used to back the provided TimeZone instances.
michael@0:  * @author Ben Fortuna
michael@0:  */
michael@0: public class TimeZoneRegistryImpl implements TimeZoneRegistry {
michael@0: 
michael@0:     private static final String DEFAULT_RESOURCE_PREFIX = "zoneinfo/";
michael@0: 
michael@0:     private static final Pattern TZ_ID_SUFFIX = Pattern.compile("(?<=/)[^/]*/[^/]*$");
michael@0:     
michael@0:     private static final String UPDATE_ENABLED = "net.fortuna.ical4j.timezone.update.enabled";
michael@0: 
michael@0:     private static final Map DEFAULT_TIMEZONES = new ConcurrentHashMap();
michael@0: 
michael@0:     private static final Properties ALIASES = new Properties();
michael@0:     static {
michael@0:         try {
michael@3:             ALIASES.load(ResourceLoader.getResourceAsStream("net/fortuna/ical4j/model/tz.alias"));
michael@3:         }
michael@0:         catch (IOException ioe) {
michael@0:             LogFactory.getLog(TimeZoneRegistryImpl.class).warn(
michael@0:                     "Error loading timezone aliases: " + ioe.getMessage());
michael@0:         }
michael@3:         try {
michael@3:         	ALIASES.load(ResourceLoader.getResourceAsStream("tz.alias"));
michael@3:         }
michael@3:         catch (Exception e) {
michael@3:         	LogFactory.getLog(TimeZoneRegistryImpl.class).debug(
michael@3:         			"Error loading custom timezone aliases: " + e.getMessage());
michael@3:         }
michael@0:     }
michael@0: 
michael@0:     private Map timezones;
michael@0: 
michael@0:     private String resourcePrefix;
michael@0: 
michael@0:     /**
michael@0:      * Default constructor.
michael@0:      */
michael@0:     public TimeZoneRegistryImpl() {
michael@0:         this(DEFAULT_RESOURCE_PREFIX);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Creates a new instance using the specified resource prefix.
michael@0:      * @param resourcePrefix a prefix prepended to classpath resource lookups for default timezones
michael@0:      */
michael@0:     public TimeZoneRegistryImpl(final String resourcePrefix) {
michael@0:         this.resourcePrefix = resourcePrefix;
michael@0:         timezones = new ConcurrentHashMap();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * {@inheritDoc}
michael@0:      */
michael@0:     public final void register(final TimeZone timezone) {
michael@0:     	// for now we only apply updates to included definitions by default..
michael@0:     	register(timezone, false);
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * {@inheritDoc}
michael@0:      */
michael@0:     public final void register(final TimeZone timezone, boolean update) {
michael@0:     	if (update) {
michael@0:             // load any available updates for the timezone..
michael@0:             timezones.put(timezone.getID(), new TimeZone(updateDefinition(timezone.getVTimeZone())));
michael@0:     	}
michael@0:     	else {
michael@0:             timezones.put(timezone.getID(), timezone);
michael@0:     	}
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * {@inheritDoc}
michael@0:      */
michael@0:     public final void clear() {
michael@0:         timezones.clear();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * {@inheritDoc}
michael@0:      */
michael@0:     public final TimeZone getTimeZone(final String id) {
michael@0:         TimeZone timezone = (TimeZone) timezones.get(id);
michael@0:         if (timezone == null) {
michael@0:             timezone = (TimeZone) DEFAULT_TIMEZONES.get(id);
michael@0:             if (timezone == null) {
michael@0:                 // if timezone not found with identifier, try loading an alias..
michael@0:                 final String alias = ALIASES.getProperty(id);
michael@0:                 if (alias != null) {
michael@0:                     return getTimeZone(alias);
michael@0:                 }
michael@0:                 else {
michael@0:                     synchronized (DEFAULT_TIMEZONES) {
michael@0:                     	// check again as it may be loaded now..
michael@0:                     	timezone = (TimeZone) DEFAULT_TIMEZONES.get(id);
michael@0:                     	if (timezone == null) {
michael@0:                             try {
michael@0:                                 final VTimeZone vTimeZone = loadVTimeZone(id);
michael@0:                                 if (vTimeZone != null) {
michael@0:                                     // XXX: temporary kludge..
michael@0:                                     // ((TzId) vTimeZone.getProperties().getProperty(Property.TZID)).setValue(id);
michael@0:                                     timezone = new TimeZone(vTimeZone);
michael@0:                                     DEFAULT_TIMEZONES.put(timezone.getID(), timezone);
michael@0:                                 }
michael@0:                                 else if (CompatibilityHints.isHintEnabled(CompatibilityHints.KEY_RELAXED_PARSING)) {
michael@0:                                     // strip global part of id and match on default tz..
michael@0:                                     Matcher matcher = TZ_ID_SUFFIX.matcher(id);
michael@0:                                     if (matcher.find()) {
michael@0:                                         return getTimeZone(matcher.group());
michael@0:                                     }
michael@0:                                 }
michael@0:                             }
michael@0:                             catch (Exception e) {
michael@0:                                 Log log = LogFactory.getLog(TimeZoneRegistryImpl.class);
michael@0:                                 log.warn("Error occurred loading VTimeZone", e);
michael@0:                             }
michael@0:                     	}
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:         return timezone;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Loads an existing VTimeZone from the classpath corresponding to the specified Java timezone.
michael@0:      */
michael@0:     private VTimeZone loadVTimeZone(final String id) throws IOException, ParserException {
michael@3:         final URL resource = ResourceLoader.getResource(resourcePrefix + id + ".ics");
michael@0:         if (resource != null) {
michael@0:             final CalendarBuilder builder = new CalendarBuilder();
michael@0:             final Calendar calendar = builder.build(resource.openStream());
michael@0:             final VTimeZone vTimeZone = (VTimeZone) calendar.getComponent(Component.VTIMEZONE);
michael@0:             // load any available updates for the timezone.. can be explicility disabled via configuration
michael@0:             if (!"false".equals(Configurator.getProperty(UPDATE_ENABLED))) {
michael@0:                 return updateDefinition(vTimeZone);
michael@0:             }
michael@0:             return vTimeZone;
michael@0:         }
michael@0:         return null;
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * @param vTimeZone
michael@0:      * @return
michael@0:      */
michael@0:     private VTimeZone updateDefinition(VTimeZone vTimeZone) {
michael@0:         final TzUrl tzUrl = vTimeZone.getTimeZoneUrl();
michael@0:         if (tzUrl != null) {
michael@0:             try {
michael@0:                 final CalendarBuilder builder = new CalendarBuilder();
michael@0:                 final Calendar calendar = builder.build(tzUrl.getUri().toURL().openStream());
michael@0:                 final VTimeZone updatedVTimeZone = (VTimeZone) calendar.getComponent(Component.VTIMEZONE);
michael@0:                 if (updatedVTimeZone != null) {
michael@0:                     return updatedVTimeZone;
michael@0:                 }
michael@0:             }
michael@0:             catch (Exception e) {
michael@0:                 Log log = LogFactory.getLog(TimeZoneRegistryImpl.class);
michael@0:                 log.warn("Unable to retrieve updates for timezone: " + vTimeZone.getTimeZoneId().getValue(), e);
michael@0:             }
michael@0:         }
michael@0:         return vTimeZone;
michael@0:     }
michael@0: }