--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/time/ZoneId.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,664 @@
+/*
+ * Copyright (c) 2012, 2016, 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) 2007-2012, 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;
+
+import java.io.DataOutput;
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.time.format.DateTimeFormatterBuilder;
+import java.time.format.TextStyle;
+import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalField;
+import java.time.temporal.TemporalQueries;
+import java.time.temporal.TemporalQuery;
+import java.time.temporal.UnsupportedTemporalTypeException;
+import java.time.zone.ZoneRules;
+import java.time.zone.ZoneRulesException;
+import java.time.zone.ZoneRulesProvider;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.TimeZone;
+
+import static java.util.Map.entry;
+
+/**
+ * A time-zone ID, such as {@code Europe/Paris}.
+ * <p>
+ * A {@code ZoneId} is used to identify the rules used to convert between
+ * an {@link Instant} and a {@link LocalDateTime}.
+ * There are two distinct types of ID:
+ * <ul>
+ * <li>Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses
+ * the same offset for all local date-times
+ * <li>Geographical regions - an area where a specific set of rules for finding
+ * the offset from UTC/Greenwich apply
+ * </ul>
+ * Most fixed offsets are represented by {@link ZoneOffset}.
+ * Calling {@link #normalized()} on any {@code ZoneId} will ensure that a
+ * fixed offset ID will be represented as a {@code ZoneOffset}.
+ * <p>
+ * The actual rules, describing when and how the offset changes, are defined by {@link ZoneRules}.
+ * This class is simply an ID used to obtain the underlying rules.
+ * This approach is taken because rules are defined by governments and change
+ * frequently, whereas the ID is stable.
+ * <p>
+ * The distinction has other effects. Serializing the {@code ZoneId} will only send
+ * the ID, whereas serializing the rules sends the entire data set.
+ * Similarly, a comparison of two IDs only examines the ID, whereas
+ * a comparison of two rules examines the entire data set.
+ *
+ * <h3>Time-zone IDs</h3>
+ * The ID is unique within the system.
+ * There are three types of ID.
+ * <p>
+ * The simplest type of ID is that from {@code ZoneOffset}.
+ * This consists of 'Z' and IDs starting with '+' or '-'.
+ * <p>
+ * The next type of ID are offset-style IDs with some form of prefix,
+ * such as 'GMT+2' or 'UTC+01:00'.
+ * The recognised prefixes are 'UTC', 'GMT' and 'UT'.
+ * The offset is the suffix and will be normalized during creation.
+ * These IDs can be normalized to a {@code ZoneOffset} using {@code normalized()}.
+ * <p>
+ * The third type of ID are region-based IDs. A region-based ID must be of
+ * two or more characters, and not start with 'UTC', 'GMT', 'UT' '+' or '-'.
+ * Region-based IDs are defined by configuration, see {@link ZoneRulesProvider}.
+ * The configuration focuses on providing the lookup from the ID to the
+ * underlying {@code ZoneRules}.
+ * <p>
+ * Time-zone rules are defined by governments and change frequently.
+ * There are a number of organizations, known here as groups, that monitor
+ * time-zone changes and collate them.
+ * The default group is the IANA Time Zone Database (TZDB).
+ * Other organizations include IATA (the airline industry body) and Microsoft.
+ * <p>
+ * Each group defines its own format for the region ID it provides.
+ * The TZDB group defines IDs such as 'Europe/London' or 'America/New_York'.
+ * TZDB IDs take precedence over other groups.
+ * <p>
+ * It is strongly recommended that the group name is included in all IDs supplied by
+ * groups other than TZDB to avoid conflicts. For example, IATA airline time-zone
+ * region IDs are typically the same as the three letter airport code.
+ * However, the airport of Utrecht has the code 'UTC', which is obviously a conflict.
+ * The recommended format for region IDs from groups other than TZDB is 'group~region'.
+ * Thus if IATA data were defined, Utrecht airport would be 'IATA~UTC'.
+ *
+ * <h3>Serialization</h3>
+ * This class can be serialized and stores the string zone ID in the external form.
+ * The {@code ZoneOffset} subclass uses a dedicated format that only stores the
+ * offset from UTC/Greenwich.
+ * <p>
+ * A {@code ZoneId} can be deserialized in a Java Runtime where the ID is unknown.
+ * For example, if a server-side Java Runtime has been updated with a new zone ID, but
+ * the client-side Java Runtime has not been updated. In this case, the {@code ZoneId}
+ * object will exist, and can be queried using {@code getId}, {@code equals},
+ * {@code hashCode}, {@code toString}, {@code getDisplayName} and {@code normalized}.
+ * However, any call to {@code getRules} will fail with {@code ZoneRulesException}.
+ * This approach is designed to allow a {@link ZonedDateTime} to be loaded and
+ * queried, but not modified, on a Java Runtime with incomplete time-zone information.
+ *
+ * <p>
+ * This is a <a href="{@docRoot}/java/lang/doc-files/ValueBased.html">value-based</a>
+ * class; use of identity-sensitive operations (including reference equality
+ * ({@code ==}), identity hash code, or synchronization) on instances of
+ * {@code ZoneId} may have unpredictable results and should be avoided.
+ * The {@code equals} method should be used for comparisons.
+ *
+ * @implSpec
+ * This abstract class has two implementations, both of which are immutable and thread-safe.
+ * One implementation models region-based IDs, the other is {@code ZoneOffset} modelling
+ * offset-based IDs. This difference is visible in serialization.
+ *
+ * @since 1.8
+ */
+public abstract class ZoneId implements Serializable {
+
+ /**
+ * A map of zone overrides to enable the short time-zone names to be used.
+ * <p>
+ * Use of short zone IDs has been deprecated in {@code java.util.TimeZone}.
+ * This map allows the IDs to continue to be used via the
+ * {@link #of(String, Map)} factory method.
+ * <p>
+ * This map contains a mapping of the IDs that is in line with TZDB 2005r and
+ * later, where 'EST', 'MST' and 'HST' map to IDs which do not include daylight
+ * savings.
+ * <p>
+ * This maps as follows:
+ * <ul>
+ * <li>EST - -05:00</li>
+ * <li>HST - -10:00</li>
+ * <li>MST - -07:00</li>
+ * <li>ACT - Australia/Darwin</li>
+ * <li>AET - Australia/Sydney</li>
+ * <li>AGT - America/Argentina/Buenos_Aires</li>
+ * <li>ART - Africa/Cairo</li>
+ * <li>AST - America/Anchorage</li>
+ * <li>BET - America/Sao_Paulo</li>
+ * <li>BST - Asia/Dhaka</li>
+ * <li>CAT - Africa/Harare</li>
+ * <li>CNT - America/St_Johns</li>
+ * <li>CST - America/Chicago</li>
+ * <li>CTT - Asia/Shanghai</li>
+ * <li>EAT - Africa/Addis_Ababa</li>
+ * <li>ECT - Europe/Paris</li>
+ * <li>IET - America/Indiana/Indianapolis</li>
+ * <li>IST - Asia/Kolkata</li>
+ * <li>JST - Asia/Tokyo</li>
+ * <li>MIT - Pacific/Apia</li>
+ * <li>NET - Asia/Yerevan</li>
+ * <li>NST - Pacific/Auckland</li>
+ * <li>PLT - Asia/Karachi</li>
+ * <li>PNT - America/Phoenix</li>
+ * <li>PRT - America/Puerto_Rico</li>
+ * <li>PST - America/Los_Angeles</li>
+ * <li>SST - Pacific/Guadalcanal</li>
+ * <li>VST - Asia/Ho_Chi_Minh</li>
+ * </ul>
+ * The map is unmodifiable.
+ */
+ public static final Map<String, String> SHORT_IDS = Map.ofEntries(
+ entry("ACT", "Australia/Darwin"),
+ entry("AET", "Australia/Sydney"),
+ entry("AGT", "America/Argentina/Buenos_Aires"),
+ entry("ART", "Africa/Cairo"),
+ entry("AST", "America/Anchorage"),
+ entry("BET", "America/Sao_Paulo"),
+ entry("BST", "Asia/Dhaka"),
+ entry("CAT", "Africa/Harare"),
+ entry("CNT", "America/St_Johns"),
+ entry("CST", "America/Chicago"),
+ entry("CTT", "Asia/Shanghai"),
+ entry("EAT", "Africa/Addis_Ababa"),
+ entry("ECT", "Europe/Paris"),
+ entry("IET", "America/Indiana/Indianapolis"),
+ entry("IST", "Asia/Kolkata"),
+ entry("JST", "Asia/Tokyo"),
+ entry("MIT", "Pacific/Apia"),
+ entry("NET", "Asia/Yerevan"),
+ entry("NST", "Pacific/Auckland"),
+ entry("PLT", "Asia/Karachi"),
+ entry("PNT", "America/Phoenix"),
+ entry("PRT", "America/Puerto_Rico"),
+ entry("PST", "America/Los_Angeles"),
+ entry("SST", "Pacific/Guadalcanal"),
+ entry("VST", "Asia/Ho_Chi_Minh"),
+ entry("EST", "-05:00"),
+ entry("MST", "-07:00"),
+ entry("HST", "-10:00")
+ );
+ /**
+ * Serialization version.
+ */
+ private static final long serialVersionUID = 8352817235686L;
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the system default time-zone.
+ * <p>
+ * This queries {@link TimeZone#getDefault()} to find the default time-zone
+ * and converts it to a {@code ZoneId}. If the system default time-zone is changed,
+ * then the result of this method will also change.
+ *
+ * @return the zone ID, not null
+ * @throws DateTimeException if the converted zone ID has an invalid format
+ * @throws ZoneRulesException if the converted zone region ID cannot be found
+ */
+ public static ZoneId systemDefault() {
+ return TimeZone.getDefault().toZoneId();
+ }
+
+ /**
+ * Gets the set of available zone IDs.
+ * <p>
+ * This set includes the string form of all available region-based IDs.
+ * Offset-based zone IDs are not included in the returned set.
+ * The ID can be passed to {@link #of(String)} to create a {@code ZoneId}.
+ * <p>
+ * The set of zone IDs can increase over time, although in a typical application
+ * the set of IDs is fixed. Each call to this method is thread-safe.
+ *
+ * @return a modifiable copy of the set of zone IDs, not null
+ */
+ public static Set<String> getAvailableZoneIds() {
+ return new HashSet<String>(ZoneRulesProvider.getAvailableZoneIds());
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code ZoneId} using its ID using a map
+ * of aliases to supplement the standard zone IDs.
+ * <p>
+ * Many users of time-zones use short abbreviations, such as PST for
+ * 'Pacific Standard Time' and PDT for 'Pacific Daylight Time'.
+ * These abbreviations are not unique, and so cannot be used as IDs.
+ * This method allows a map of string to time-zone to be setup and reused
+ * within an application.
+ *
+ * @param zoneId the time-zone ID, not null
+ * @param aliasMap a map of alias zone IDs (typically abbreviations) to real zone IDs, not null
+ * @return the zone ID, not null
+ * @throws DateTimeException if the zone ID has an invalid format
+ * @throws ZoneRulesException if the zone ID is a region ID that cannot be found
+ */
+ public static ZoneId of(String zoneId, Map<String, String> aliasMap) {
+ Objects.requireNonNull(zoneId, "zoneId");
+ Objects.requireNonNull(aliasMap, "aliasMap");
+ String id = Objects.requireNonNullElse(aliasMap.get(zoneId), zoneId);
+ return of(id);
+ }
+
+ /**
+ * Obtains an instance of {@code ZoneId} from an ID ensuring that the
+ * ID is valid and available for use.
+ * <p>
+ * This method parses the ID producing a {@code ZoneId} or {@code ZoneOffset}.
+ * A {@code ZoneOffset} is returned if the ID is 'Z', or starts with '+' or '-'.
+ * The result will always be a valid ID for which {@link ZoneRules} can be obtained.
+ * <p>
+ * Parsing matches the zone ID step by step as follows.
+ * <ul>
+ * <li>If the zone ID equals 'Z', the result is {@code ZoneOffset.UTC}.
+ * <li>If the zone ID consists of a single letter, the zone ID is invalid
+ * and {@code DateTimeException} is thrown.
+ * <li>If the zone ID starts with '+' or '-', the ID is parsed as a
+ * {@code ZoneOffset} using {@link ZoneOffset#of(String)}.
+ * <li>If the zone ID equals 'GMT', 'UTC' or 'UT' then the result is a {@code ZoneId}
+ * with the same ID and rules equivalent to {@code ZoneOffset.UTC}.
+ * <li>If the zone ID starts with 'UTC+', 'UTC-', 'GMT+', 'GMT-', 'UT+' or 'UT-'
+ * then the ID is a prefixed offset-based ID. The ID is split in two, with
+ * a two or three letter prefix and a suffix starting with the sign.
+ * The suffix is parsed as a {@link ZoneOffset#of(String) ZoneOffset}.
+ * The result will be a {@code ZoneId} with the specified UTC/GMT/UT prefix
+ * and the normalized offset ID as per {@link ZoneOffset#getId()}.
+ * The rules of the returned {@code ZoneId} will be equivalent to the
+ * parsed {@code ZoneOffset}.
+ * <li>All other IDs are parsed as region-based zone IDs. Region IDs must
+ * match the regular expression <code>[A-Za-z][A-Za-z0-9~/._+-]+</code>
+ * otherwise a {@code DateTimeException} is thrown. If the zone ID is not
+ * in the configured set of IDs, {@code ZoneRulesException} is thrown.
+ * The detailed format of the region ID depends on the group supplying the data.
+ * The default set of data is supplied by the IANA Time Zone Database (TZDB).
+ * This has region IDs of the form '{area}/{city}', such as 'Europe/Paris' or 'America/New_York'.
+ * This is compatible with most IDs from {@link java.util.TimeZone}.
+ * </ul>
+ *
+ * @param zoneId the time-zone ID, not null
+ * @return the zone ID, not null
+ * @throws DateTimeException if the zone ID has an invalid format
+ * @throws ZoneRulesException if the zone ID is a region ID that cannot be found
+ */
+ public static ZoneId of(String zoneId) {
+ return of(zoneId, true);
+ }
+
+ /**
+ * Obtains an instance of {@code ZoneId} wrapping an offset.
+ * <p>
+ * If the prefix is "GMT", "UTC", or "UT" a {@code ZoneId}
+ * with the prefix and the non-zero offset is returned.
+ * If the prefix is empty {@code ""} the {@code ZoneOffset} is returned.
+ *
+ * @param prefix the time-zone ID, not null
+ * @param offset the offset, not null
+ * @return the zone ID, not null
+ * @throws IllegalArgumentException if the prefix is not one of
+ * "GMT", "UTC", or "UT", or ""
+ */
+ public static ZoneId ofOffset(String prefix, ZoneOffset offset) {
+ Objects.requireNonNull(prefix, "prefix");
+ Objects.requireNonNull(offset, "offset");
+ if (prefix.length() == 0) {
+ return offset;
+ }
+
+ if (!prefix.equals("GMT") && !prefix.equals("UTC") && !prefix.equals("UT")) {
+ throw new IllegalArgumentException("prefix should be GMT, UTC or UT, is: " + prefix);
+ }
+
+ if (offset.getTotalSeconds() != 0) {
+ prefix = prefix.concat(offset.getId());
+ }
+ return new ZoneRegion(prefix, offset.getRules());
+ }
+
+ /**
+ * Parses the ID, taking a flag to indicate whether {@code ZoneRulesException}
+ * should be thrown or not, used in deserialization.
+ *
+ * @param zoneId the time-zone ID, not null
+ * @param checkAvailable whether to check if the zone ID is available
+ * @return the zone ID, not null
+ * @throws DateTimeException if the ID format is invalid
+ * @throws ZoneRulesException if checking availability and the ID cannot be found
+ */
+ static ZoneId of(String zoneId, boolean checkAvailable) {
+ Objects.requireNonNull(zoneId, "zoneId");
+ if (zoneId.length() <= 1 || zoneId.startsWith("+") || zoneId.startsWith("-")) {
+ return ZoneOffset.of(zoneId);
+ } else if (zoneId.startsWith("UTC") || zoneId.startsWith("GMT")) {
+ return ofWithPrefix(zoneId, 3, checkAvailable);
+ } else if (zoneId.startsWith("UT")) {
+ return ofWithPrefix(zoneId, 2, checkAvailable);
+ }
+ return ZoneRegion.ofId(zoneId, checkAvailable);
+ }
+
+ /**
+ * Parse once a prefix is established.
+ *
+ * @param zoneId the time-zone ID, not null
+ * @param prefixLength the length of the prefix, 2 or 3
+ * @return the zone ID, not null
+ * @throws DateTimeException if the zone ID has an invalid format
+ */
+ private static ZoneId ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable) {
+ String prefix = zoneId.substring(0, prefixLength);
+ if (zoneId.length() == prefixLength) {
+ return ofOffset(prefix, ZoneOffset.UTC);
+ }
+ if (zoneId.charAt(prefixLength) != '+' && zoneId.charAt(prefixLength) != '-') {
+ return ZoneRegion.ofId(zoneId, checkAvailable); // drop through to ZoneRulesProvider
+ }
+ try {
+ ZoneOffset offset = ZoneOffset.of(zoneId.substring(prefixLength));
+ if (offset == ZoneOffset.UTC) {
+ return ofOffset(prefix, offset);
+ }
+ return ofOffset(prefix, offset);
+ } catch (DateTimeException ex) {
+ throw new DateTimeException("Invalid ID for offset-based ZoneId: " + zoneId, ex);
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code ZoneId} from a temporal object.
+ * <p>
+ * This obtains a zone based on the specified temporal.
+ * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
+ * which this factory converts to an instance of {@code ZoneId}.
+ * <p>
+ * A {@code TemporalAccessor} represents some form of date and time information.
+ * This factory converts the arbitrary temporal object to an instance of {@code ZoneId}.
+ * <p>
+ * The conversion will try to obtain the zone in a way that favours region-based
+ * zones over offset-based zones using {@link TemporalQueries#zone()}.
+ * <p>
+ * This method matches the signature of the functional interface {@link TemporalQuery}
+ * allowing it to be used as a query via method reference, {@code ZoneId::from}.
+ *
+ * @param temporal the temporal object to convert, not null
+ * @return the zone ID, not null
+ * @throws DateTimeException if unable to convert to a {@code ZoneId}
+ */
+ public static ZoneId from(TemporalAccessor temporal) {
+ ZoneId obj = temporal.query(TemporalQueries.zone());
+ if (obj == null) {
+ throw new DateTimeException("Unable to obtain ZoneId from TemporalAccessor: " +
+ temporal + " of type " + temporal.getClass().getName());
+ }
+ return obj;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Constructor only accessible within the package.
+ */
+ ZoneId() {
+ if (getClass() != ZoneOffset.class && getClass() != ZoneRegion.class) {
+ throw new AssertionError("Invalid subclass");
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the unique time-zone ID.
+ * <p>
+ * This ID uniquely defines this object.
+ * The format of an offset based ID is defined by {@link ZoneOffset#getId()}.
+ *
+ * @return the time-zone unique ID, not null
+ */
+ public abstract String getId();
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the textual representation of the zone, such as 'British Time' or
+ * '+02:00'.
+ * <p>
+ * This returns the textual name used to identify the time-zone ID,
+ * suitable for presentation to the user.
+ * The parameters control the style of the returned text and the locale.
+ * <p>
+ * If no textual mapping is found then the {@link #getId() full ID} is returned.
+ *
+ * @param style the length of the text required, not null
+ * @param locale the locale to use, not null
+ * @return the text value of the zone, not null
+ */
+ public String getDisplayName(TextStyle style, Locale locale) {
+ return new DateTimeFormatterBuilder().appendZoneText(style).toFormatter(locale).format(toTemporal());
+ }
+
+ /**
+ * Converts this zone to a {@code TemporalAccessor}.
+ * <p>
+ * A {@code ZoneId} can be fully represented as a {@code TemporalAccessor}.
+ * However, the interface is not implemented by this class as most of the
+ * methods on the interface have no meaning to {@code ZoneId}.
+ * <p>
+ * The returned temporal has no supported fields, with the query method
+ * supporting the return of the zone using {@link TemporalQueries#zoneId()}.
+ *
+ * @return a temporal equivalent to this zone, not null
+ */
+ private TemporalAccessor toTemporal() {
+ return new TemporalAccessor() {
+ @Override
+ public boolean isSupported(TemporalField field) {
+ return false;
+ }
+ @Override
+ public long getLong(TemporalField field) {
+ throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
+ }
+ @SuppressWarnings("unchecked")
+ @Override
+ public <R> R query(TemporalQuery<R> query) {
+ if (query == TemporalQueries.zoneId()) {
+ return (R) ZoneId.this;
+ }
+ return TemporalAccessor.super.query(query);
+ }
+ };
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the time-zone rules for this ID allowing calculations to be performed.
+ * <p>
+ * The rules provide the functionality associated with a time-zone,
+ * such as finding the offset for a given instant or local date-time.
+ * <p>
+ * A time-zone can be invalid if it is deserialized in a Java Runtime which
+ * does not have the same rules loaded as the Java Runtime that stored it.
+ * In this case, calling this method will throw a {@code ZoneRulesException}.
+ * <p>
+ * The rules are supplied by {@link ZoneRulesProvider}. An advanced provider may
+ * support dynamic updates to the rules without restarting the Java Runtime.
+ * If so, then the result of this method may change over time.
+ * Each individual call will be still remain thread-safe.
+ * <p>
+ * {@link ZoneOffset} will always return a set of rules where the offset never changes.
+ *
+ * @return the rules, not null
+ * @throws ZoneRulesException if no rules are available for this ID
+ */
+ public abstract ZoneRules getRules();
+
+ /**
+ * Normalizes the time-zone ID, returning a {@code ZoneOffset} where possible.
+ * <p>
+ * The returns a normalized {@code ZoneId} that can be used in place of this ID.
+ * The result will have {@code ZoneRules} equivalent to those returned by this object,
+ * however the ID returned by {@code getId()} may be different.
+ * <p>
+ * The normalization checks if the rules of this {@code ZoneId} have a fixed offset.
+ * If they do, then the {@code ZoneOffset} equal to that offset is returned.
+ * Otherwise {@code this} is returned.
+ *
+ * @return the time-zone unique ID, not null
+ */
+ public ZoneId normalized() {
+ try {
+ ZoneRules rules = getRules();
+ if (rules.isFixedOffset()) {
+ return rules.getOffset(Instant.EPOCH);
+ }
+ } catch (ZoneRulesException ex) {
+ // invalid ZoneRegion is not important to this method
+ }
+ return this;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Checks if this time-zone ID is equal to another time-zone ID.
+ * <p>
+ * The comparison is based on the ID.
+ *
+ * @param obj the object to check, null returns false
+ * @return true if this is equal to the other time-zone ID
+ */
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj instanceof ZoneId) {
+ ZoneId other = (ZoneId) obj;
+ return getId().equals(other.getId());
+ }
+ return false;
+ }
+
+ /**
+ * A hash code for this time-zone ID.
+ *
+ * @return a suitable hash code
+ */
+ @Override
+ public int hashCode() {
+ return getId().hashCode();
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Defend against malicious streams.
+ *
+ * @param s the stream to read
+ * @throws InvalidObjectException always
+ */
+ private void readObject(ObjectInputStream s) throws InvalidObjectException {
+ throw new InvalidObjectException("Deserialization via serialization delegate");
+ }
+
+ /**
+ * Outputs this zone as a {@code String}, using the ID.
+ *
+ * @return a string representation of this time-zone ID, not null
+ */
+ @Override
+ public String toString() {
+ return getId();
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Writes the object using a
+ * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
+ * @serialData
+ * <pre>
+ * out.writeByte(7); // identifies a ZoneId (not ZoneOffset)
+ * out.writeUTF(getId());
+ * </pre>
+ * <p>
+ * When read back in, the {@code ZoneId} will be created as though using
+ * {@link #of(String)}, but without any exception in the case where the
+ * ID has a valid format, but is not in the known set of region-based IDs.
+ *
+ * @return the instance of {@code Ser}, not null
+ */
+ // this is here for serialization Javadoc
+ private Object writeReplace() {
+ return new Ser(Ser.ZONE_REGION_TYPE, this);
+ }
+
+ abstract void write(DataOutput out) throws IOException;
+
+}