--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/time/zone/ZoneRulesProvider.java Tue Jan 22 20:59:21 2013 -0800
@@ -0,0 +1,412 @@
+/*
+ * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Copyright (c) 2009-2012, Stephen Colebourne & Michael Nascimento Santos
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * * Neither the name of JSR-310 nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package java.time.zone;
+
+import java.time.DateTimeException;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NavigableMap;
+import java.util.Objects;
+import java.util.ServiceConfigurationError;
+import java.util.ServiceLoader;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Provider of time-zone rules to the system.
+ * <p>
+ * This class manages the configuration of time-zone rules.
+ * The static methods provide the public API that can be used to manage the providers.
+ * The abstract methods provide the SPI that allows rules to be provided.
+ * <p>
+ * Rules are looked up primarily by zone ID, as used by {@link ZoneId}.
+ * Only zone region IDs may be used, zone offset IDs are not used here.
+ * <p>
+ * Time-zone rules are political, thus the data can change at any time.
+ * Each provider will provide the latest rules for each zone ID, but they
+ * may also provide the history of how the rules changed.
+ *
+ * <h3>Specification for implementors</h3>
+ * This interface is a service provider that can be called by multiple threads.
+ * Implementations must be immutable and thread-safe.
+ * <p>
+ * Providers must ensure that once a rule has been seen by the application, the
+ * rule must continue to be available.
+ * <p>
+ * Many systems would like to update time-zone rules dynamically without stopping the JVM.
+ * When examined in detail, this is a complex problem.
+ * Providers may choose to handle dynamic updates, however the default provider does not.
+ *
+ * @since 1.8
+ */
+public abstract class ZoneRulesProvider {
+
+ /**
+ * The set of loaded providers.
+ */
+ private static final CopyOnWriteArrayList<ZoneRulesProvider> PROVIDERS = new CopyOnWriteArrayList<>();
+ /**
+ * The lookup from zone region ID to provider.
+ */
+ private static final ConcurrentMap<String, ZoneRulesProvider> ZONES = new ConcurrentHashMap<>(512, 0.75f, 2);
+ static {
+ registerProvider(new TzdbZoneRulesProvider());
+ ServiceLoader<ZoneRulesProvider> sl = ServiceLoader.load(ZoneRulesProvider.class, ClassLoader.getSystemClassLoader());
+ List<ZoneRulesProvider> loaded = new ArrayList<>();
+ Iterator<ZoneRulesProvider> it = sl.iterator();
+ while (it.hasNext()) {
+ ZoneRulesProvider provider;
+ try {
+ provider = it.next();
+ } catch (ServiceConfigurationError ex) {
+ if (ex.getCause() instanceof SecurityException) {
+ continue; // ignore the security exception, try the next provider
+ }
+ throw ex;
+ }
+ registerProvider0(provider);
+ }
+ // CopyOnWriteList could be slow if lots of providers and each added individually
+ PROVIDERS.addAll(loaded);
+ }
+
+ //-------------------------------------------------------------------------
+ /**
+ * Gets the set of available zone IDs.
+ * <p>
+ * These zone IDs are loaded and available for use by {@code ZoneId}.
+ *
+ * @return a modifiable copy of the set of zone IDs, not null
+ */
+ public static Set<String> getAvailableZoneIds() {
+ return new HashSet<>(ZONES.keySet());
+ }
+
+ /**
+ * Gets the rules for the zone ID.
+ * <p>
+ * This returns the latest available rules for the zone ID.
+ * <p>
+ * This method relies on time-zone data provider files that are configured.
+ * These are loaded using a {@code ServiceLoader}.
+ *
+ * @param zoneId the zone region ID as used by {@code ZoneId}, not null
+ * @return the rules for the ID, not null
+ * @throws ZoneRulesException if the zone ID is unknown
+ */
+ public static ZoneRules getRules(String zoneId) {
+ Objects.requireNonNull(zoneId, "zoneId");
+ return getProvider(zoneId).provideRules(zoneId);
+ }
+
+ /**
+ * Gets the history of rules for the zone ID.
+ * <p>
+ * Time-zones are defined by governments and change frequently.
+ * This method allows applications to find the history of changes to the
+ * rules for a single zone ID. The map is keyed by a string, which is the
+ * version string associated with the rules.
+ * <p>
+ * The exact meaning and format of the version is provider specific.
+ * The version must follow lexicographical order, thus the returned map will
+ * be order from the oldest known rules to the newest available rules.
+ * The default 'TZDB' group uses version numbering consisting of the year
+ * followed by a letter, such as '2009e' or '2012f'.
+ * <p>
+ * Implementations must provide a result for each valid zone ID, however
+ * they do not have to provide a history of rules.
+ * Thus the map will always contain one element, and will only contain more
+ * than one element if historical rule information is available.
+ *
+ * @param zoneId the zone region ID as used by {@code ZoneId}, not null
+ * @return a modifiable copy of the history of the rules for the ID, sorted
+ * from oldest to newest, not null
+ * @throws ZoneRulesException if the zone ID is unknown
+ */
+ public static NavigableMap<String, ZoneRules> getVersions(String zoneId) {
+ Objects.requireNonNull(zoneId, "zoneId");
+ return getProvider(zoneId).provideVersions(zoneId);
+ }
+
+ /**
+ * Gets the provider for the zone ID.
+ *
+ * @param zoneId the zone region ID as used by {@code ZoneId}, not null
+ * @return the provider, not null
+ * @throws ZoneRulesException if the zone ID is unknown
+ */
+ private static ZoneRulesProvider getProvider(String zoneId) {
+ ZoneRulesProvider provider = ZONES.get(zoneId);
+ if (provider == null) {
+ if (ZONES.isEmpty()) {
+ throw new ZoneRulesException("No time-zone data files registered");
+ }
+ throw new ZoneRulesException("Unknown time-zone ID: " + zoneId);
+ }
+ return provider;
+ }
+
+ //-------------------------------------------------------------------------
+ /**
+ * Registers a zone rules provider.
+ * <p>
+ * This adds a new provider to those currently available.
+ * A provider supplies rules for one or more zone IDs.
+ * A provider cannot be registered if it supplies a zone ID that has already been
+ * registered. See the notes on time-zone IDs in {@link ZoneId}, especially
+ * the section on using the concept of a "group" to make IDs unique.
+ * <p>
+ * To ensure the integrity of time-zones already created, there is no way
+ * to deregister providers.
+ *
+ * @param provider the provider to register, not null
+ * @throws ZoneRulesException if a region is already registered
+ */
+ public static void registerProvider(ZoneRulesProvider provider) {
+ Objects.requireNonNull(provider, "provider");
+ registerProvider0(provider);
+ PROVIDERS.add(provider);
+ }
+
+ /**
+ * Registers the provider.
+ *
+ * @param provider the provider to register, not null
+ * @throws ZoneRulesException if unable to complete the registration
+ */
+ private static void registerProvider0(ZoneRulesProvider provider) {
+ for (String zoneId : provider.provideZoneIds()) {
+ Objects.requireNonNull(zoneId, "zoneId");
+ ZoneRulesProvider old = ZONES.putIfAbsent(zoneId, provider.provideBind(zoneId));
+ if (old != null) {
+ throw new ZoneRulesException(
+ "Unable to register zone as one already registered with that ID: " + zoneId +
+ ", currently loading from provider: " + provider);
+ }
+ }
+ }
+
+ //-------------------------------------------------------------------------
+ /**
+ * Refreshes the rules from the underlying data provider.
+ * <p>
+ * This method is an extension point that allows providers to refresh their
+ * rules dynamically at a time of the applications choosing.
+ * After calling this method, the offset stored in any {@link ZonedDateTime}
+ * may be invalid for the zone ID.
+ * <p>
+ * Dynamic behavior is entirely optional and most providers, including the
+ * default provider, do not support it.
+ *
+ * @return true if the rules were updated
+ * @throws ZoneRulesException if an error occurs during the refresh
+ */
+ public static boolean refresh() {
+ boolean changed = false;
+ for (ZoneRulesProvider provider : PROVIDERS) {
+ changed |= provider.provideRefresh();
+ }
+ return changed;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Constructor.
+ */
+ protected ZoneRulesProvider() {
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * SPI method to get the available zone IDs.
+ * <p>
+ * This obtains the IDs that this {@code ZoneRulesProvider} provides.
+ * A provider should provide data for at least one region.
+ * <p>
+ * The returned regions remain available and valid for the lifetime of the application.
+ * A dynamic provider may increase the set of regions as more data becomes available.
+ *
+ * @return the unmodifiable set of region IDs being provided, not null
+ */
+ protected abstract Set<String> provideZoneIds();
+
+ /**
+ * SPI method to bind to the specified zone ID.
+ * <p>
+ * {@code ZoneRulesProvider} has a lookup from zone ID to provider.
+ * This method is used when building that lookup, allowing providers
+ * to insert a derived provider that is precisely tuned to the zone ID.
+ * This replaces two hash map lookups by one, enhancing performance.
+ * <p>
+ * This optimization is optional. Returning {@code this} is acceptable.
+ * <p>
+ * This implementation creates a bound provider that caches the
+ * rules from the underlying provider. The request to version history
+ * is forward on to the underlying. This is suitable for providers that
+ * cannot change their contents during the lifetime of the JVM.
+ *
+ * @param zoneId the zone region ID as used by {@code ZoneId}, not null
+ * @return the resolved provider for the ID, not null
+ * @throws DateTimeException if there is no provider for the specified group
+ */
+ protected ZoneRulesProvider provideBind(String zoneId) {
+ return new BoundProvider(this, zoneId);
+ }
+
+ /**
+ * SPI method to get the rules for the zone ID.
+ * <p>
+ * This loads the rules for the region and version specified.
+ * The version may be null to indicate the "latest" version.
+ *
+ * @param regionId the time-zone region ID, not null
+ * @return the rules, not null
+ * @throws DateTimeException if rules cannot be obtained
+ */
+ protected abstract ZoneRules provideRules(String regionId);
+
+ /**
+ * SPI method to get the history of rules for the zone ID.
+ * <p>
+ * This returns a map of historical rules keyed by a version string.
+ * The exact meaning and format of the version is provider specific.
+ * The version must follow lexicographical order, thus the returned map will
+ * be order from the oldest known rules to the newest available rules.
+ * The default 'TZDB' group uses version numbering consisting of the year
+ * followed by a letter, such as '2009e' or '2012f'.
+ * <p>
+ * Implementations must provide a result for each valid zone ID, however
+ * they do not have to provide a history of rules.
+ * Thus the map will always contain one element, and will only contain more
+ * than one element if historical rule information is available.
+ * <p>
+ * The returned versions remain available and valid for the lifetime of the application.
+ * A dynamic provider may increase the set of versions as more data becomes available.
+ *
+ * @param zoneId the zone region ID as used by {@code ZoneId}, not null
+ * @return a modifiable copy of the history of the rules for the ID, sorted
+ * from oldest to newest, not null
+ * @throws ZoneRulesException if the zone ID is unknown
+ */
+ protected abstract NavigableMap<String, ZoneRules> provideVersions(String zoneId);
+
+ /**
+ * SPI method to refresh the rules from the underlying data provider.
+ * <p>
+ * This method provides the opportunity for a provider to dynamically
+ * recheck the underlying data provider to find the latest rules.
+ * This could be used to load new rules without stopping the JVM.
+ * Dynamic behavior is entirely optional and most providers do not support it.
+ * <p>
+ * This implementation returns false.
+ *
+ * @return true if the rules were updated
+ * @throws DateTimeException if an error occurs during the refresh
+ */
+ protected boolean provideRefresh() {
+ return false;
+ }
+
+ //-------------------------------------------------------------------------
+ /**
+ * A provider bound to a single zone ID.
+ */
+ private static class BoundProvider extends ZoneRulesProvider {
+ private final ZoneRulesProvider provider;
+ private final String zoneId;
+ private final ZoneRules rules;
+
+ private BoundProvider(ZoneRulesProvider provider, String zoneId) {
+ this.provider = provider;
+ this.zoneId = zoneId;
+ this.rules = provider.provideRules(zoneId);
+ }
+
+ @Override
+ protected Set<String> provideZoneIds() {
+ return new HashSet<>(Collections.singleton(zoneId));
+ }
+
+ @Override
+ protected ZoneRules provideRules(String regionId) {
+ return rules;
+ }
+
+ @Override
+ protected NavigableMap<String, ZoneRules> provideVersions(String zoneId) {
+ return provider.provideVersions(zoneId);
+ }
+
+ @Override
+ public String toString() {
+ return zoneId;
+ }
+ }
+
+}