| /* |
| * 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.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.io.InvalidObjectException; |
| import java.io.ObjectInputStream; |
| import java.io.Serializable; |
| import java.time.Duration; |
| import java.time.Instant; |
| import java.time.LocalDate; |
| import java.time.LocalDateTime; |
| import java.time.ZoneId; |
| import java.time.ZoneOffset; |
| import java.time.Year; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Objects; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| |
| // Android-changed: remove mention of ZoneRulesProvider. |
| /** |
| * The rules defining how the zone offset varies for a single time-zone. |
| * <p> |
| * The rules model all the historic and future transitions for a time-zone. |
| * {@link ZoneOffsetTransition} is used for known transitions, typically historic. |
| * {@link ZoneOffsetTransitionRule} is used for future transitions that are based |
| * on the result of an algorithm. |
| * <p> |
| * The same rules may be shared internally between multiple zone IDs. |
| * <p> |
| * Serializing an instance of {@code ZoneRules} will store the entire set of rules. |
| * It does not store the zone ID as it is not part of the state of this object. |
| * <p> |
| * A rule implementation may or may not store full information about historic |
| * and future transitions, and the information stored is only as accurate as |
| * that supplied to the implementation by the rules provider. |
| * Applications should treat the data provided as representing the best information |
| * available to the implementation of this rule. |
| * |
| * @implSpec |
| * This class is immutable and thread-safe. |
| * |
| * @since 1.8 |
| */ |
| public final class ZoneRules implements Serializable { |
| |
| /** |
| * Serialization version. |
| */ |
| private static final long serialVersionUID = 3044319355680032515L; |
| /** |
| * The last year to have its transitions cached. |
| */ |
| private static final int LAST_CACHED_YEAR = 2100; |
| |
| /** |
| * The transitions between standard offsets (epoch seconds), sorted. |
| */ |
| private final long[] standardTransitions; |
| /** |
| * The standard offsets. |
| */ |
| private final ZoneOffset[] standardOffsets; |
| /** |
| * The transitions between instants (epoch seconds), sorted. |
| */ |
| private final long[] savingsInstantTransitions; |
| /** |
| * The transitions between local date-times, sorted. |
| * This is a paired array, where the first entry is the start of the transition |
| * and the second entry is the end of the transition. |
| */ |
| private final LocalDateTime[] savingsLocalTransitions; |
| /** |
| * The wall offsets. |
| */ |
| private final ZoneOffset[] wallOffsets; |
| /** |
| * The last rule. |
| */ |
| private final ZoneOffsetTransitionRule[] lastRules; |
| /** |
| * The map of recent transitions. |
| */ |
| private final transient ConcurrentMap<Integer, ZoneOffsetTransition[]> lastRulesCache = |
| new ConcurrentHashMap<Integer, ZoneOffsetTransition[]>(); |
| /** |
| * The zero-length long array. |
| */ |
| private static final long[] EMPTY_LONG_ARRAY = new long[0]; |
| /** |
| * The zero-length lastrules array. |
| */ |
| private static final ZoneOffsetTransitionRule[] EMPTY_LASTRULES = |
| new ZoneOffsetTransitionRule[0]; |
| /** |
| * The zero-length ldt array. |
| */ |
| private static final LocalDateTime[] EMPTY_LDT_ARRAY = new LocalDateTime[0]; |
| |
| /** |
| * Obtains an instance of a ZoneRules. |
| * |
| * @param baseStandardOffset the standard offset to use before legal rules were set, not null |
| * @param baseWallOffset the wall offset to use before legal rules were set, not null |
| * @param standardOffsetTransitionList the list of changes to the standard offset, not null |
| * @param transitionList the list of transitions, not null |
| * @param lastRules the recurring last rules, size 16 or less, not null |
| * @return the zone rules, not null |
| */ |
| public static ZoneRules of(ZoneOffset baseStandardOffset, |
| ZoneOffset baseWallOffset, |
| List<ZoneOffsetTransition> standardOffsetTransitionList, |
| List<ZoneOffsetTransition> transitionList, |
| List<ZoneOffsetTransitionRule> lastRules) { |
| Objects.requireNonNull(baseStandardOffset, "baseStandardOffset"); |
| Objects.requireNonNull(baseWallOffset, "baseWallOffset"); |
| Objects.requireNonNull(standardOffsetTransitionList, "standardOffsetTransitionList"); |
| Objects.requireNonNull(transitionList, "transitionList"); |
| Objects.requireNonNull(lastRules, "lastRules"); |
| return new ZoneRules(baseStandardOffset, baseWallOffset, |
| standardOffsetTransitionList, transitionList, lastRules); |
| } |
| |
| /** |
| * Obtains an instance of ZoneRules that has fixed zone rules. |
| * |
| * @param offset the offset this fixed zone rules is based on, not null |
| * @return the zone rules, not null |
| * @see #isFixedOffset() |
| */ |
| public static ZoneRules of(ZoneOffset offset) { |
| Objects.requireNonNull(offset, "offset"); |
| return new ZoneRules(offset); |
| } |
| |
| /** |
| * Creates an instance. |
| * |
| * @param baseStandardOffset the standard offset to use before legal rules were set, not null |
| * @param baseWallOffset the wall offset to use before legal rules were set, not null |
| * @param standardOffsetTransitionList the list of changes to the standard offset, not null |
| * @param transitionList the list of transitions, not null |
| * @param lastRules the recurring last rules, size 16 or less, not null |
| */ |
| ZoneRules(ZoneOffset baseStandardOffset, |
| ZoneOffset baseWallOffset, |
| List<ZoneOffsetTransition> standardOffsetTransitionList, |
| List<ZoneOffsetTransition> transitionList, |
| List<ZoneOffsetTransitionRule> lastRules) { |
| super(); |
| |
| // convert standard transitions |
| |
| this.standardTransitions = new long[standardOffsetTransitionList.size()]; |
| |
| this.standardOffsets = new ZoneOffset[standardOffsetTransitionList.size() + 1]; |
| this.standardOffsets[0] = baseStandardOffset; |
| for (int i = 0; i < standardOffsetTransitionList.size(); i++) { |
| this.standardTransitions[i] = standardOffsetTransitionList.get(i).toEpochSecond(); |
| this.standardOffsets[i + 1] = standardOffsetTransitionList.get(i).getOffsetAfter(); |
| } |
| |
| // convert savings transitions to locals |
| List<LocalDateTime> localTransitionList = new ArrayList<>(); |
| List<ZoneOffset> localTransitionOffsetList = new ArrayList<>(); |
| localTransitionOffsetList.add(baseWallOffset); |
| for (ZoneOffsetTransition trans : transitionList) { |
| if (trans.isGap()) { |
| localTransitionList.add(trans.getDateTimeBefore()); |
| localTransitionList.add(trans.getDateTimeAfter()); |
| } else { |
| localTransitionList.add(trans.getDateTimeAfter()); |
| localTransitionList.add(trans.getDateTimeBefore()); |
| } |
| localTransitionOffsetList.add(trans.getOffsetAfter()); |
| } |
| this.savingsLocalTransitions = localTransitionList.toArray(new LocalDateTime[localTransitionList.size()]); |
| this.wallOffsets = localTransitionOffsetList.toArray(new ZoneOffset[localTransitionOffsetList.size()]); |
| |
| // convert savings transitions to instants |
| this.savingsInstantTransitions = new long[transitionList.size()]; |
| for (int i = 0; i < transitionList.size(); i++) { |
| this.savingsInstantTransitions[i] = transitionList.get(i).toEpochSecond(); |
| } |
| |
| // last rules |
| if (lastRules.size() > 16) { |
| throw new IllegalArgumentException("Too many transition rules"); |
| } |
| this.lastRules = lastRules.toArray(new ZoneOffsetTransitionRule[lastRules.size()]); |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param standardTransitions the standard transitions, not null |
| * @param standardOffsets the standard offsets, not null |
| * @param savingsInstantTransitions the standard transitions, not null |
| * @param wallOffsets the wall offsets, not null |
| * @param lastRules the recurring last rules, size 15 or less, not null |
| */ |
| private ZoneRules(long[] standardTransitions, |
| ZoneOffset[] standardOffsets, |
| long[] savingsInstantTransitions, |
| ZoneOffset[] wallOffsets, |
| ZoneOffsetTransitionRule[] lastRules) { |
| super(); |
| |
| this.standardTransitions = standardTransitions; |
| this.standardOffsets = standardOffsets; |
| this.savingsInstantTransitions = savingsInstantTransitions; |
| this.wallOffsets = wallOffsets; |
| this.lastRules = lastRules; |
| |
| if (savingsInstantTransitions.length == 0) { |
| this.savingsLocalTransitions = EMPTY_LDT_ARRAY; |
| } else { |
| // convert savings transitions to locals |
| List<LocalDateTime> localTransitionList = new ArrayList<>(); |
| for (int i = 0; i < savingsInstantTransitions.length; i++) { |
| ZoneOffset before = wallOffsets[i]; |
| ZoneOffset after = wallOffsets[i + 1]; |
| ZoneOffsetTransition trans = new ZoneOffsetTransition(savingsInstantTransitions[i], before, after); |
| if (trans.isGap()) { |
| localTransitionList.add(trans.getDateTimeBefore()); |
| localTransitionList.add(trans.getDateTimeAfter()); |
| } else { |
| localTransitionList.add(trans.getDateTimeAfter()); |
| localTransitionList.add(trans.getDateTimeBefore()); |
| } |
| } |
| this.savingsLocalTransitions = localTransitionList.toArray(new LocalDateTime[localTransitionList.size()]); |
| } |
| } |
| |
| /** |
| * Creates an instance of ZoneRules that has fixed zone rules. |
| * |
| * @param offset the offset this fixed zone rules is based on, not null |
| * @return the zone rules, not null |
| * @see #isFixedOffset() |
| */ |
| private ZoneRules(ZoneOffset offset) { |
| this.standardOffsets = new ZoneOffset[1]; |
| this.standardOffsets[0] = offset; |
| this.standardTransitions = EMPTY_LONG_ARRAY; |
| this.savingsInstantTransitions = EMPTY_LONG_ARRAY; |
| this.savingsLocalTransitions = EMPTY_LDT_ARRAY; |
| this.wallOffsets = standardOffsets; |
| this.lastRules = EMPTY_LASTRULES; |
| } |
| |
| /** |
| * 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"); |
| } |
| |
| /** |
| * Writes the object using a |
| * <a href="../../../serialized-form.html#java.time.zone.Ser">dedicated serialized form</a>. |
| * @serialData |
| * <pre style="font-size:1.0em">{@code |
| * |
| * out.writeByte(1); // identifies a ZoneRules |
| * out.writeInt(standardTransitions.length); |
| * for (long trans : standardTransitions) { |
| * Ser.writeEpochSec(trans, out); |
| * } |
| * for (ZoneOffset offset : standardOffsets) { |
| * Ser.writeOffset(offset, out); |
| * } |
| * out.writeInt(savingsInstantTransitions.length); |
| * for (long trans : savingsInstantTransitions) { |
| * Ser.writeEpochSec(trans, out); |
| * } |
| * for (ZoneOffset offset : wallOffsets) { |
| * Ser.writeOffset(offset, out); |
| * } |
| * out.writeByte(lastRules.length); |
| * for (ZoneOffsetTransitionRule rule : lastRules) { |
| * rule.writeExternal(out); |
| * } |
| * } |
| * </pre> |
| * <p> |
| * Epoch second values used for offsets are encoded in a variable |
| * length form to make the common cases put fewer bytes in the stream. |
| * <pre style="font-size:1.0em">{@code |
| * |
| * static void writeEpochSec(long epochSec, DataOutput out) throws IOException { |
| * if (epochSec >= -4575744000L && epochSec < 10413792000L && epochSec % 900 == 0) { // quarter hours between 1825 and 2300 |
| * int store = (int) ((epochSec + 4575744000L) / 900); |
| * out.writeByte((store >>> 16) & 255); |
| * out.writeByte((store >>> 8) & 255); |
| * out.writeByte(store & 255); |
| * } else { |
| * out.writeByte(255); |
| * out.writeLong(epochSec); |
| * } |
| * } |
| * } |
| * </pre> |
| * <p> |
| * ZoneOffset values are encoded in a variable length form so the |
| * common cases put fewer bytes in the stream. |
| * <pre style="font-size:1.0em">{@code |
| * |
| * static void writeOffset(ZoneOffset offset, DataOutput out) throws IOException { |
| * final int offsetSecs = offset.getTotalSeconds(); |
| * int offsetByte = offsetSecs % 900 == 0 ? offsetSecs / 900 : 127; // compress to -72 to +72 |
| * out.writeByte(offsetByte); |
| * if (offsetByte == 127) { |
| * out.writeInt(offsetSecs); |
| * } |
| * } |
| *} |
| * </pre> |
| * @return the replacing object, not null |
| */ |
| private Object writeReplace() { |
| return new Ser(Ser.ZRULES, this); |
| } |
| |
| /** |
| * Writes the state to the stream. |
| * |
| * @param out the output stream, not null |
| * @throws IOException if an error occurs |
| */ |
| void writeExternal(DataOutput out) throws IOException { |
| out.writeInt(standardTransitions.length); |
| for (long trans : standardTransitions) { |
| Ser.writeEpochSec(trans, out); |
| } |
| for (ZoneOffset offset : standardOffsets) { |
| Ser.writeOffset(offset, out); |
| } |
| out.writeInt(savingsInstantTransitions.length); |
| for (long trans : savingsInstantTransitions) { |
| Ser.writeEpochSec(trans, out); |
| } |
| for (ZoneOffset offset : wallOffsets) { |
| Ser.writeOffset(offset, out); |
| } |
| out.writeByte(lastRules.length); |
| for (ZoneOffsetTransitionRule rule : lastRules) { |
| rule.writeExternal(out); |
| } |
| } |
| |
| /** |
| * Reads the state from the stream. |
| * |
| * @param in the input stream, not null |
| * @return the created object, not null |
| * @throws IOException if an error occurs |
| */ |
| static ZoneRules readExternal(DataInput in) throws IOException, ClassNotFoundException { |
| int stdSize = in.readInt(); |
| long[] stdTrans = (stdSize == 0) ? EMPTY_LONG_ARRAY |
| : new long[stdSize]; |
| for (int i = 0; i < stdSize; i++) { |
| stdTrans[i] = Ser.readEpochSec(in); |
| } |
| ZoneOffset[] stdOffsets = new ZoneOffset[stdSize + 1]; |
| for (int i = 0; i < stdOffsets.length; i++) { |
| stdOffsets[i] = Ser.readOffset(in); |
| } |
| int savSize = in.readInt(); |
| long[] savTrans = (savSize == 0) ? EMPTY_LONG_ARRAY |
| : new long[savSize]; |
| for (int i = 0; i < savSize; i++) { |
| savTrans[i] = Ser.readEpochSec(in); |
| } |
| ZoneOffset[] savOffsets = new ZoneOffset[savSize + 1]; |
| for (int i = 0; i < savOffsets.length; i++) { |
| savOffsets[i] = Ser.readOffset(in); |
| } |
| int ruleSize = in.readByte(); |
| ZoneOffsetTransitionRule[] rules = (ruleSize == 0) ? |
| EMPTY_LASTRULES : new ZoneOffsetTransitionRule[ruleSize]; |
| for (int i = 0; i < ruleSize; i++) { |
| rules[i] = ZoneOffsetTransitionRule.readExternal(in); |
| } |
| return new ZoneRules(stdTrans, stdOffsets, savTrans, savOffsets, rules); |
| } |
| |
| /** |
| * Checks of the zone rules are fixed, such that the offset never varies. |
| * |
| * @return true if the time-zone is fixed and the offset never changes |
| */ |
| public boolean isFixedOffset() { |
| return savingsInstantTransitions.length == 0; |
| } |
| |
| /** |
| * Gets the offset applicable at the specified instant in these rules. |
| * <p> |
| * The mapping from an instant to an offset is simple, there is only |
| * one valid offset for each instant. |
| * This method returns that offset. |
| * |
| * @param instant the instant to find the offset for, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the offset, not null |
| */ |
| public ZoneOffset getOffset(Instant instant) { |
| if (savingsInstantTransitions.length == 0) { |
| return standardOffsets[0]; |
| } |
| long epochSec = instant.getEpochSecond(); |
| // check if using last rules |
| if (lastRules.length > 0 && |
| epochSec > savingsInstantTransitions[savingsInstantTransitions.length - 1]) { |
| int year = findYear(epochSec, wallOffsets[wallOffsets.length - 1]); |
| ZoneOffsetTransition[] transArray = findTransitionArray(year); |
| ZoneOffsetTransition trans = null; |
| for (int i = 0; i < transArray.length; i++) { |
| trans = transArray[i]; |
| if (epochSec < trans.toEpochSecond()) { |
| return trans.getOffsetBefore(); |
| } |
| } |
| return trans.getOffsetAfter(); |
| } |
| |
| // using historic rules |
| int index = Arrays.binarySearch(savingsInstantTransitions, epochSec); |
| if (index < 0) { |
| // switch negative insert position to start of matched range |
| index = -index - 2; |
| } |
| return wallOffsets[index + 1]; |
| } |
| |
| /** |
| * Gets a suitable offset for the specified local date-time in these rules. |
| * <p> |
| * The mapping from a local date-time to an offset is not straightforward. |
| * There are three cases: |
| * <ul> |
| * <li>Normal, with one valid offset. For the vast majority of the year, the normal |
| * case applies, where there is a single valid offset for the local date-time.</li> |
| * <li>Gap, with zero valid offsets. This is when clocks jump forward typically |
| * due to the spring daylight savings change from "winter" to "summer". |
| * In a gap there are local date-time values with no valid offset.</li> |
| * <li>Overlap, with two valid offsets. This is when clocks are set back typically |
| * due to the autumn daylight savings change from "summer" to "winter". |
| * In an overlap there are local date-time values with two valid offsets.</li> |
| * </ul> |
| * Thus, for any given local date-time there can be zero, one or two valid offsets. |
| * This method returns the single offset in the Normal case, and in the Gap or Overlap |
| * case it returns the offset before the transition. |
| * <p> |
| * Since, in the case of Gap and Overlap, the offset returned is a "best" value, rather |
| * than the "correct" value, it should be treated with care. Applications that care |
| * about the correct offset should use a combination of this method, |
| * {@link #getValidOffsets(LocalDateTime)} and {@link #getTransition(LocalDateTime)}. |
| * |
| * @param localDateTime the local date-time to query, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the best available offset for the local date-time, not null |
| */ |
| public ZoneOffset getOffset(LocalDateTime localDateTime) { |
| Object info = getOffsetInfo(localDateTime); |
| if (info instanceof ZoneOffsetTransition) { |
| return ((ZoneOffsetTransition) info).getOffsetBefore(); |
| } |
| return (ZoneOffset) info; |
| } |
| |
| /** |
| * Gets the offset applicable at the specified local date-time in these rules. |
| * <p> |
| * The mapping from a local date-time to an offset is not straightforward. |
| * There are three cases: |
| * <ul> |
| * <li>Normal, with one valid offset. For the vast majority of the year, the normal |
| * case applies, where there is a single valid offset for the local date-time.</li> |
| * <li>Gap, with zero valid offsets. This is when clocks jump forward typically |
| * due to the spring daylight savings change from "winter" to "summer". |
| * In a gap there are local date-time values with no valid offset.</li> |
| * <li>Overlap, with two valid offsets. This is when clocks are set back typically |
| * due to the autumn daylight savings change from "summer" to "winter". |
| * In an overlap there are local date-time values with two valid offsets.</li> |
| * </ul> |
| * Thus, for any given local date-time there can be zero, one or two valid offsets. |
| * This method returns that list of valid offsets, which is a list of size 0, 1 or 2. |
| * In the case where there are two offsets, the earlier offset is returned at index 0 |
| * and the later offset at index 1. |
| * <p> |
| * There are various ways to handle the conversion from a {@code LocalDateTime}. |
| * One technique, using this method, would be: |
| * <pre> |
| * List<ZoneOffset> validOffsets = rules.getOffset(localDT); |
| * if (validOffsets.size() == 1) { |
| * // Normal case: only one valid offset |
| * zoneOffset = validOffsets.get(0); |
| * } else { |
| * // Gap or Overlap: determine what to do from transition (which will be non-null) |
| * ZoneOffsetTransition trans = rules.getTransition(localDT); |
| * } |
| * </pre> |
| * <p> |
| * In theory, it is possible for there to be more than two valid offsets. |
| * This would happen if clocks to be put back more than once in quick succession. |
| * This has never happened in the history of time-zones and thus has no special handling. |
| * However, if it were to happen, then the list would return more than 2 entries. |
| * |
| * @param localDateTime the local date-time to query for valid offsets, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the list of valid offsets, may be immutable, not null |
| */ |
| public List<ZoneOffset> getValidOffsets(LocalDateTime localDateTime) { |
| // should probably be optimized |
| Object info = getOffsetInfo(localDateTime); |
| if (info instanceof ZoneOffsetTransition) { |
| return ((ZoneOffsetTransition) info).getValidOffsets(); |
| } |
| return Collections.singletonList((ZoneOffset) info); |
| } |
| |
| /** |
| * Gets the offset transition applicable at the specified local date-time in these rules. |
| * <p> |
| * The mapping from a local date-time to an offset is not straightforward. |
| * There are three cases: |
| * <ul> |
| * <li>Normal, with one valid offset. For the vast majority of the year, the normal |
| * case applies, where there is a single valid offset for the local date-time.</li> |
| * <li>Gap, with zero valid offsets. This is when clocks jump forward typically |
| * due to the spring daylight savings change from "winter" to "summer". |
| * In a gap there are local date-time values with no valid offset.</li> |
| * <li>Overlap, with two valid offsets. This is when clocks are set back typically |
| * due to the autumn daylight savings change from "summer" to "winter". |
| * In an overlap there are local date-time values with two valid offsets.</li> |
| * </ul> |
| * A transition is used to model the cases of a Gap or Overlap. |
| * The Normal case will return null. |
| * <p> |
| * There are various ways to handle the conversion from a {@code LocalDateTime}. |
| * One technique, using this method, would be: |
| * <pre> |
| * ZoneOffsetTransition trans = rules.getTransition(localDT); |
| * if (trans == null) { |
| * // Gap or Overlap: determine what to do from transition |
| * } else { |
| * // Normal case: only one valid offset |
| * zoneOffset = rule.getOffset(localDT); |
| * } |
| * </pre> |
| * |
| * @param localDateTime the local date-time to query for offset transition, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the offset transition, null if the local date-time is not in transition |
| */ |
| public ZoneOffsetTransition getTransition(LocalDateTime localDateTime) { |
| Object info = getOffsetInfo(localDateTime); |
| return (info instanceof ZoneOffsetTransition ? (ZoneOffsetTransition) info : null); |
| } |
| |
| private Object getOffsetInfo(LocalDateTime dt) { |
| if (savingsInstantTransitions.length == 0) { |
| return standardOffsets[0]; |
| } |
| // check if using last rules |
| if (lastRules.length > 0 && |
| dt.isAfter(savingsLocalTransitions[savingsLocalTransitions.length - 1])) { |
| ZoneOffsetTransition[] transArray = findTransitionArray(dt.getYear()); |
| Object info = null; |
| for (ZoneOffsetTransition trans : transArray) { |
| info = findOffsetInfo(dt, trans); |
| if (info instanceof ZoneOffsetTransition || info.equals(trans.getOffsetBefore())) { |
| return info; |
| } |
| } |
| return info; |
| } |
| |
| // using historic rules |
| int index = Arrays.binarySearch(savingsLocalTransitions, dt); |
| if (index == -1) { |
| // before first transition |
| return wallOffsets[0]; |
| } |
| if (index < 0) { |
| // switch negative insert position to start of matched range |
| index = -index - 2; |
| } else if (index < savingsLocalTransitions.length - 1 && |
| savingsLocalTransitions[index].equals(savingsLocalTransitions[index + 1])) { |
| // handle overlap immediately following gap |
| index++; |
| } |
| if ((index & 1) == 0) { |
| // gap or overlap |
| LocalDateTime dtBefore = savingsLocalTransitions[index]; |
| LocalDateTime dtAfter = savingsLocalTransitions[index + 1]; |
| ZoneOffset offsetBefore = wallOffsets[index / 2]; |
| ZoneOffset offsetAfter = wallOffsets[index / 2 + 1]; |
| if (offsetAfter.getTotalSeconds() > offsetBefore.getTotalSeconds()) { |
| // gap |
| return new ZoneOffsetTransition(dtBefore, offsetBefore, offsetAfter); |
| } else { |
| // overlap |
| return new ZoneOffsetTransition(dtAfter, offsetBefore, offsetAfter); |
| } |
| } else { |
| // normal (neither gap or overlap) |
| return wallOffsets[index / 2 + 1]; |
| } |
| } |
| |
| /** |
| * Finds the offset info for a local date-time and transition. |
| * |
| * @param dt the date-time, not null |
| * @param trans the transition, not null |
| * @return the offset info, not null |
| */ |
| private Object findOffsetInfo(LocalDateTime dt, ZoneOffsetTransition trans) { |
| LocalDateTime localTransition = trans.getDateTimeBefore(); |
| if (trans.isGap()) { |
| if (dt.isBefore(localTransition)) { |
| return trans.getOffsetBefore(); |
| } |
| if (dt.isBefore(trans.getDateTimeAfter())) { |
| return trans; |
| } else { |
| return trans.getOffsetAfter(); |
| } |
| } else { |
| if (dt.isBefore(localTransition) == false) { |
| return trans.getOffsetAfter(); |
| } |
| if (dt.isBefore(trans.getDateTimeAfter())) { |
| return trans.getOffsetBefore(); |
| } else { |
| return trans; |
| } |
| } |
| } |
| |
| /** |
| * Finds the appropriate transition array for the given year. |
| * |
| * @param year the year, not null |
| * @return the transition array, not null |
| */ |
| private ZoneOffsetTransition[] findTransitionArray(int year) { |
| Integer yearObj = year; // should use Year class, but this saves a class load |
| ZoneOffsetTransition[] transArray = lastRulesCache.get(yearObj); |
| if (transArray != null) { |
| return transArray; |
| } |
| ZoneOffsetTransitionRule[] ruleArray = lastRules; |
| transArray = new ZoneOffsetTransition[ruleArray.length]; |
| for (int i = 0; i < ruleArray.length; i++) { |
| transArray[i] = ruleArray[i].createTransition(year); |
| } |
| if (year < LAST_CACHED_YEAR) { |
| lastRulesCache.putIfAbsent(yearObj, transArray); |
| } |
| return transArray; |
| } |
| |
| /** |
| * Gets the standard offset for the specified instant in this zone. |
| * <p> |
| * This provides access to historic information on how the standard offset |
| * has changed over time. |
| * The standard offset is the offset before any daylight saving time is applied. |
| * This is typically the offset applicable during winter. |
| * |
| * @param instant the instant to find the offset information for, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the standard offset, not null |
| */ |
| public ZoneOffset getStandardOffset(Instant instant) { |
| if (savingsInstantTransitions.length == 0) { |
| return standardOffsets[0]; |
| } |
| long epochSec = instant.getEpochSecond(); |
| int index = Arrays.binarySearch(standardTransitions, epochSec); |
| if (index < 0) { |
| // switch negative insert position to start of matched range |
| index = -index - 2; |
| } |
| return standardOffsets[index + 1]; |
| } |
| |
| /** |
| * Gets the amount of daylight savings in use for the specified instant in this zone. |
| * <p> |
| * This provides access to historic information on how the amount of daylight |
| * savings has changed over time. |
| * This is the difference between the standard offset and the actual offset. |
| * Typically the amount is zero during winter and one hour during summer. |
| * Time-zones are second-based, so the nanosecond part of the duration will be zero. |
| * <p> |
| * This default implementation calculates the duration from the |
| * {@link #getOffset(java.time.Instant) actual} and |
| * {@link #getStandardOffset(java.time.Instant) standard} offsets. |
| * |
| * @param instant the instant to find the daylight savings for, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the difference between the standard and actual offset, not null |
| */ |
| public Duration getDaylightSavings(Instant instant) { |
| if (savingsInstantTransitions.length == 0) { |
| return Duration.ZERO; |
| } |
| ZoneOffset standardOffset = getStandardOffset(instant); |
| ZoneOffset actualOffset = getOffset(instant); |
| return Duration.ofSeconds(actualOffset.getTotalSeconds() - standardOffset.getTotalSeconds()); |
| } |
| |
| /** |
| * Checks if the specified instant is in daylight savings. |
| * <p> |
| * This checks if the standard offset and the actual offset are the same |
| * for the specified instant. |
| * If they are not, it is assumed that daylight savings is in operation. |
| * <p> |
| * This default implementation compares the {@link #getOffset(java.time.Instant) actual} |
| * and {@link #getStandardOffset(java.time.Instant) standard} offsets. |
| * |
| * @param instant the instant to find the offset information for, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the standard offset, not null |
| */ |
| public boolean isDaylightSavings(Instant instant) { |
| return (getStandardOffset(instant).equals(getOffset(instant)) == false); |
| } |
| |
| /** |
| * Checks if the offset date-time is valid for these rules. |
| * <p> |
| * To be valid, the local date-time must not be in a gap and the offset |
| * must match one of the valid offsets. |
| * <p> |
| * This default implementation checks if {@link #getValidOffsets(java.time.LocalDateTime)} |
| * contains the specified offset. |
| * |
| * @param localDateTime the date-time to check, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @param offset the offset to check, null returns false |
| * @return true if the offset date-time is valid for these rules |
| */ |
| public boolean isValidOffset(LocalDateTime localDateTime, ZoneOffset offset) { |
| return getValidOffsets(localDateTime).contains(offset); |
| } |
| |
| /** |
| * Gets the next transition after the specified instant. |
| * <p> |
| * This returns details of the next transition after the specified instant. |
| * For example, if the instant represents a point where "Summer" daylight savings time |
| * applies, then the method will return the transition to the next "Winter" time. |
| * |
| * @param instant the instant to get the next transition after, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the next transition after the specified instant, null if this is after the last transition |
| */ |
| public ZoneOffsetTransition nextTransition(Instant instant) { |
| if (savingsInstantTransitions.length == 0) { |
| return null; |
| } |
| long epochSec = instant.getEpochSecond(); |
| // check if using last rules |
| if (epochSec >= savingsInstantTransitions[savingsInstantTransitions.length - 1]) { |
| if (lastRules.length == 0) { |
| return null; |
| } |
| // search year the instant is in |
| int year = findYear(epochSec, wallOffsets[wallOffsets.length - 1]); |
| ZoneOffsetTransition[] transArray = findTransitionArray(year); |
| for (ZoneOffsetTransition trans : transArray) { |
| if (epochSec < trans.toEpochSecond()) { |
| return trans; |
| } |
| } |
| // use first from following year |
| if (year < Year.MAX_VALUE) { |
| transArray = findTransitionArray(year + 1); |
| return transArray[0]; |
| } |
| return null; |
| } |
| |
| // using historic rules |
| int index = Arrays.binarySearch(savingsInstantTransitions, epochSec); |
| if (index < 0) { |
| index = -index - 1; // switched value is the next transition |
| } else { |
| index += 1; // exact match, so need to add one to get the next |
| } |
| return new ZoneOffsetTransition(savingsInstantTransitions[index], wallOffsets[index], wallOffsets[index + 1]); |
| } |
| |
| /** |
| * Gets the previous transition before the specified instant. |
| * <p> |
| * This returns details of the previous transition after the specified instant. |
| * For example, if the instant represents a point where "summer" daylight saving time |
| * applies, then the method will return the transition from the previous "winter" time. |
| * |
| * @param instant the instant to get the previous transition after, not null, but null |
| * may be ignored if the rules have a single offset for all instants |
| * @return the previous transition after the specified instant, null if this is before the first transition |
| */ |
| public ZoneOffsetTransition previousTransition(Instant instant) { |
| if (savingsInstantTransitions.length == 0) { |
| return null; |
| } |
| long epochSec = instant.getEpochSecond(); |
| if (instant.getNano() > 0 && epochSec < Long.MAX_VALUE) { |
| epochSec += 1; // allow rest of method to only use seconds |
| } |
| |
| // check if using last rules |
| long lastHistoric = savingsInstantTransitions[savingsInstantTransitions.length - 1]; |
| if (lastRules.length > 0 && epochSec > lastHistoric) { |
| // search year the instant is in |
| ZoneOffset lastHistoricOffset = wallOffsets[wallOffsets.length - 1]; |
| int year = findYear(epochSec, lastHistoricOffset); |
| ZoneOffsetTransition[] transArray = findTransitionArray(year); |
| for (int i = transArray.length - 1; i >= 0; i--) { |
| if (epochSec > transArray[i].toEpochSecond()) { |
| return transArray[i]; |
| } |
| } |
| // use last from preceding year |
| int lastHistoricYear = findYear(lastHistoric, lastHistoricOffset); |
| if (--year > lastHistoricYear) { |
| transArray = findTransitionArray(year); |
| return transArray[transArray.length - 1]; |
| } |
| // drop through |
| } |
| |
| // using historic rules |
| int index = Arrays.binarySearch(savingsInstantTransitions, epochSec); |
| if (index < 0) { |
| index = -index - 1; |
| } |
| if (index <= 0) { |
| return null; |
| } |
| return new ZoneOffsetTransition(savingsInstantTransitions[index - 1], wallOffsets[index - 1], wallOffsets[index]); |
| } |
| |
| private int findYear(long epochSecond, ZoneOffset offset) { |
| // inline for performance |
| long localSecond = epochSecond + offset.getTotalSeconds(); |
| long localEpochDay = Math.floorDiv(localSecond, 86400); |
| return LocalDate.ofEpochDay(localEpochDay).getYear(); |
| } |
| |
| /** |
| * Gets the complete list of fully defined transitions. |
| * <p> |
| * The complete set of transitions for this rules instance is defined by this method |
| * and {@link #getTransitionRules()}. This method returns those transitions that have |
| * been fully defined. These are typically historical, but may be in the future. |
| * <p> |
| * The list will be empty for fixed offset rules and for any time-zone where there has |
| * only ever been a single offset. The list will also be empty if the transition rules are unknown. |
| * |
| * @return an immutable list of fully defined transitions, not null |
| */ |
| public List<ZoneOffsetTransition> getTransitions() { |
| List<ZoneOffsetTransition> list = new ArrayList<>(); |
| for (int i = 0; i < savingsInstantTransitions.length; i++) { |
| list.add(new ZoneOffsetTransition(savingsInstantTransitions[i], wallOffsets[i], wallOffsets[i + 1])); |
| } |
| return Collections.unmodifiableList(list); |
| } |
| |
| /** |
| * Gets the list of transition rules for years beyond those defined in the transition list. |
| * <p> |
| * The complete set of transitions for this rules instance is defined by this method |
| * and {@link #getTransitions()}. This method returns instances of {@link ZoneOffsetTransitionRule} |
| * that define an algorithm for when transitions will occur. |
| * <p> |
| * For any given {@code ZoneRules}, this list contains the transition rules for years |
| * beyond those years that have been fully defined. These rules typically refer to future |
| * daylight saving time rule changes. |
| * <p> |
| * If the zone defines daylight savings into the future, then the list will normally |
| * be of size two and hold information about entering and exiting daylight savings. |
| * If the zone does not have daylight savings, or information about future changes |
| * is uncertain, then the list will be empty. |
| * <p> |
| * The list will be empty for fixed offset rules and for any time-zone where there is no |
| * daylight saving time. The list will also be empty if the transition rules are unknown. |
| * |
| * @return an immutable list of transition rules, not null |
| */ |
| public List<ZoneOffsetTransitionRule> getTransitionRules() { |
| return Collections.unmodifiableList(Arrays.asList(lastRules)); |
| } |
| |
| /** |
| * Checks if this set of rules equals another. |
| * <p> |
| * Two rule sets are equal if they will always result in the same output |
| * for any given input instant or local date-time. |
| * Rules from two different groups may return false even if they are in fact the same. |
| * <p> |
| * This definition should result in implementations comparing their entire state. |
| * |
| * @param otherRules the other rules, null returns false |
| * @return true if this rules is the same as that specified |
| */ |
| @Override |
| public boolean equals(Object otherRules) { |
| if (this == otherRules) { |
| return true; |
| } |
| if (otherRules instanceof ZoneRules) { |
| ZoneRules other = (ZoneRules) otherRules; |
| return Arrays.equals(standardTransitions, other.standardTransitions) && |
| Arrays.equals(standardOffsets, other.standardOffsets) && |
| Arrays.equals(savingsInstantTransitions, other.savingsInstantTransitions) && |
| Arrays.equals(wallOffsets, other.wallOffsets) && |
| Arrays.equals(lastRules, other.lastRules); |
| } |
| return false; |
| } |
| |
| /** |
| * Returns a suitable hash code given the definition of {@code #equals}. |
| * |
| * @return the hash code |
| */ |
| @Override |
| public int hashCode() { |
| return Arrays.hashCode(standardTransitions) ^ |
| Arrays.hashCode(standardOffsets) ^ |
| Arrays.hashCode(savingsInstantTransitions) ^ |
| Arrays.hashCode(wallOffsets) ^ |
| Arrays.hashCode(lastRules); |
| } |
| |
| /** |
| * Returns a string describing this object. |
| * |
| * @return a string for debugging, not null |
| */ |
| @Override |
| public String toString() { |
| return "ZoneRules[currentStandardOffset=" + standardOffsets[standardOffsets.length - 1] + "]"; |
| } |
| |
| } |
