--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/time/ZoneOffset.java Tue Jan 22 20:59:21 2013 -0800
@@ -0,0 +1,789 @@
+/*
+ * 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) 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 static java.time.temporal.ChronoField.OFFSET_SECONDS;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.ObjectStreamException;
+import java.io.Serializable;
+import java.time.temporal.ChronoField;
+import java.time.temporal.Queries;
+import java.time.temporal.Temporal;
+import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalAdjuster;
+import java.time.temporal.TemporalField;
+import java.time.temporal.TemporalQuery;
+import java.time.temporal.ValueRange;
+import java.time.zone.ZoneRules;
+import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * A time-zone offset from Greenwich/UTC, such as {@code +02:00}.
+ * <p>
+ * A time-zone offset is the period of time that a time-zone differs from Greenwich/UTC.
+ * This is usually a fixed number of hours and minutes.
+ * <p>
+ * Different parts of the world have different time-zone offsets.
+ * The rules for how offsets vary by place and time of year are captured in the
+ * {@link ZoneId} class.
+ * <p>
+ * For example, Paris is one hour ahead of Greenwich/UTC in winter and two hours
+ * ahead in summer. The {@code ZoneId} instance for Paris will reference two
+ * {@code ZoneOffset} instances - a {@code +01:00} instance for winter,
+ * and a {@code +02:00} instance for summer.
+ * <p>
+ * In 2008, time-zone offsets around the world extended from -12:00 to +14:00.
+ * To prevent any problems with that range being extended, yet still provide
+ * validation, the range of offsets is restricted to -18:00 to 18:00 inclusive.
+ * <p>
+ * This class is designed for use with the ISO calendar system.
+ * The fields of hours, minutes and seconds make assumptions that are valid for the
+ * standard ISO definitions of those fields. This class may be used with other
+ * calendar systems providing the definition of the time fields matches those
+ * of the ISO calendar system.
+ * <p>
+ * Instances of {@code ZoneOffset} must be compared using {@link #equals}.
+ * Implementations may choose to cache certain common offsets, however
+ * applications must not rely on such caching.
+ *
+ * <h3>Specification for implementors</h3>
+ * This class is immutable and thread-safe.
+ *
+ * @since 1.8
+ */
+public final class ZoneOffset
+ extends ZoneId
+ implements TemporalAccessor, TemporalAdjuster, Comparable<ZoneOffset>, Serializable {
+
+ /** Cache of time-zone offset by offset in seconds. */
+ private static final ConcurrentMap<Integer, ZoneOffset> SECONDS_CACHE = new ConcurrentHashMap<>(16, 0.75f, 4);
+ /** Cache of time-zone offset by ID. */
+ private static final ConcurrentMap<String, ZoneOffset> ID_CACHE = new ConcurrentHashMap<>(16, 0.75f, 4);
+
+ /**
+ * The number of seconds per hour.
+ */
+ private static final int SECONDS_PER_HOUR = 60 * 60;
+ /**
+ * The number of seconds per minute.
+ */
+ private static final int SECONDS_PER_MINUTE = 60;
+ /**
+ * The number of minutes per hour.
+ */
+ private static final int MINUTES_PER_HOUR = 60;
+ /**
+ * The abs maximum seconds.
+ */
+ private static final int MAX_SECONDS = 18 * SECONDS_PER_HOUR;
+ /**
+ * Serialization version.
+ */
+ private static final long serialVersionUID = 2357656521762053153L;
+
+ /**
+ * The time-zone offset for UTC, with an ID of 'Z'.
+ */
+ public static final ZoneOffset UTC = ZoneOffset.ofTotalSeconds(0);
+ /**
+ * Constant for the maximum supported offset.
+ */
+ public static final ZoneOffset MIN = ZoneOffset.ofTotalSeconds(-MAX_SECONDS);
+ /**
+ * Constant for the maximum supported offset.
+ */
+ public static final ZoneOffset MAX = ZoneOffset.ofTotalSeconds(MAX_SECONDS);
+
+ /**
+ * The total offset in seconds.
+ */
+ private final int totalSeconds;
+ /**
+ * The string form of the time-zone offset.
+ */
+ private final transient String id;
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code ZoneOffset} using the ID.
+ * <p>
+ * This method parses the string ID of a {@code ZoneOffset} to
+ * return an instance. The parsing accepts all the formats generated by
+ * {@link #getId()}, plus some additional formats:
+ * <p><ul>
+ * <li>{@code Z} - for UTC
+ * <li>{@code +h}
+ * <li>{@code +hh}
+ * <li>{@code +hh:mm}
+ * <li>{@code -hh:mm}
+ * <li>{@code +hhmm}
+ * <li>{@code -hhmm}
+ * <li>{@code +hh:mm:ss}
+ * <li>{@code -hh:mm:ss}
+ * <li>{@code +hhmmss}
+ * <li>{@code -hhmmss}
+ * </ul><p>
+ * Note that ± means either the plus or minus symbol.
+ * <p>
+ * The ID of the returned offset will be normalized to one of the formats
+ * described by {@link #getId()}.
+ * <p>
+ * The maximum supported range is from +18:00 to -18:00 inclusive.
+ *
+ * @param offsetId the offset ID, not null
+ * @return the zone-offset, not null
+ * @throws DateTimeException if the offset ID is invalid
+ */
+ @SuppressWarnings("fallthrough")
+ public static ZoneOffset of(String offsetId) {
+ Objects.requireNonNull(offsetId, "offsetId");
+ // "Z" is always in the cache
+ ZoneOffset offset = ID_CACHE.get(offsetId);
+ if (offset != null) {
+ return offset;
+ }
+
+ // parse - +h, +hh, +hhmm, +hh:mm, +hhmmss, +hh:mm:ss
+ final int hours, minutes, seconds;
+ switch (offsetId.length()) {
+ case 2:
+ offsetId = offsetId.charAt(0) + "0" + offsetId.charAt(1); // fallthru
+ case 3:
+ hours = parseNumber(offsetId, 1, false);
+ minutes = 0;
+ seconds = 0;
+ break;
+ case 5:
+ hours = parseNumber(offsetId, 1, false);
+ minutes = parseNumber(offsetId, 3, false);
+ seconds = 0;
+ break;
+ case 6:
+ hours = parseNumber(offsetId, 1, false);
+ minutes = parseNumber(offsetId, 4, true);
+ seconds = 0;
+ break;
+ case 7:
+ hours = parseNumber(offsetId, 1, false);
+ minutes = parseNumber(offsetId, 3, false);
+ seconds = parseNumber(offsetId, 5, false);
+ break;
+ case 9:
+ hours = parseNumber(offsetId, 1, false);
+ minutes = parseNumber(offsetId, 4, true);
+ seconds = parseNumber(offsetId, 7, true);
+ break;
+ default:
+ throw new DateTimeException("Zone offset ID '" + offsetId + "' is invalid");
+ }
+ char first = offsetId.charAt(0);
+ if (first != '+' && first != '-') {
+ throw new DateTimeException("Zone offset ID '" + offsetId + "' is invalid: Plus/minus not found when expected");
+ }
+ if (first == '-') {
+ return ofHoursMinutesSeconds(-hours, -minutes, -seconds);
+ } else {
+ return ofHoursMinutesSeconds(hours, minutes, seconds);
+ }
+ }
+
+ /**
+ * Parse a two digit zero-prefixed number.
+ *
+ * @param offsetId the offset ID, not null
+ * @param pos the position to parse, valid
+ * @param precededByColon should this number be prefixed by a precededByColon
+ * @return the parsed number, from 0 to 99
+ */
+ private static int parseNumber(CharSequence offsetId, int pos, boolean precededByColon) {
+ if (precededByColon && offsetId.charAt(pos - 1) != ':') {
+ throw new DateTimeException("Zone offset ID '" + offsetId + "' is invalid: Colon not found when expected");
+ }
+ char ch1 = offsetId.charAt(pos);
+ char ch2 = offsetId.charAt(pos + 1);
+ if (ch1 < '0' || ch1 > '9' || ch2 < '0' || ch2 > '9') {
+ throw new DateTimeException("Zone offset ID '" + offsetId + "' is invalid: Non numeric characters found");
+ }
+ return (ch1 - 48) * 10 + (ch2 - 48);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code ZoneOffset} using an offset in hours.
+ *
+ * @param hours the time-zone offset in hours, from -18 to +18
+ * @return the zone-offset, not null
+ * @throws DateTimeException if the offset is not in the required range
+ */
+ public static ZoneOffset ofHours(int hours) {
+ return ofHoursMinutesSeconds(hours, 0, 0);
+ }
+
+ /**
+ * Obtains an instance of {@code ZoneOffset} using an offset in
+ * hours and minutes.
+ * <p>
+ * The sign of the hours and minutes components must match.
+ * Thus, if the hours is negative, the minutes must be negative or zero.
+ * If the hours is zero, the minutes may be positive, negative or zero.
+ *
+ * @param hours the time-zone offset in hours, from -18 to +18
+ * @param minutes the time-zone offset in minutes, from 0 to ±59, sign matches hours
+ * @return the zone-offset, not null
+ * @throws DateTimeException if the offset is not in the required range
+ */
+ public static ZoneOffset ofHoursMinutes(int hours, int minutes) {
+ return ofHoursMinutesSeconds(hours, minutes, 0);
+ }
+
+ /**
+ * Obtains an instance of {@code ZoneOffset} using an offset in
+ * hours, minutes and seconds.
+ * <p>
+ * The sign of the hours, minutes and seconds components must match.
+ * Thus, if the hours is negative, the minutes and seconds must be negative or zero.
+ *
+ * @param hours the time-zone offset in hours, from -18 to +18
+ * @param minutes the time-zone offset in minutes, from 0 to ±59, sign matches hours and seconds
+ * @param seconds the time-zone offset in seconds, from 0 to ±59, sign matches hours and minutes
+ * @return the zone-offset, not null
+ * @throws DateTimeException if the offset is not in the required range
+ */
+ public static ZoneOffset ofHoursMinutesSeconds(int hours, int minutes, int seconds) {
+ validate(hours, minutes, seconds);
+ int totalSeconds = totalSeconds(hours, minutes, seconds);
+ return ofTotalSeconds(totalSeconds);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code ZoneOffset} from a temporal object.
+ * <p>
+ * A {@code TemporalAccessor} represents some form of date and time information.
+ * This factory converts the arbitrary temporal object to an instance of {@code ZoneOffset}.
+ * <p>
+ * The conversion extracts the {@link ChronoField#OFFSET_SECONDS offset-seconds} field.
+ * <p>
+ * This method matches the signature of the functional interface {@link TemporalQuery}
+ * allowing it to be used in queries via method reference, {@code ZoneOffset::from}.
+ *
+ * @param temporal the temporal object to convert, not null
+ * @return the zone-offset, not null
+ * @throws DateTimeException if unable to convert to an {@code ZoneOffset}
+ */
+ public static ZoneOffset from(TemporalAccessor temporal) {
+ if (temporal instanceof ZoneOffset) {
+ return (ZoneOffset) temporal;
+ }
+ try {
+ return ofTotalSeconds(temporal.get(OFFSET_SECONDS));
+ } catch (DateTimeException ex) {
+ throw new DateTimeException("Unable to obtain ZoneOffset from TemporalAccessor: " + temporal.getClass(), ex);
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Validates the offset fields.
+ *
+ * @param hours the time-zone offset in hours, from -18 to +18
+ * @param minutes the time-zone offset in minutes, from 0 to ±59
+ * @param seconds the time-zone offset in seconds, from 0 to ±59
+ * @throws DateTimeException if the offset is not in the required range
+ */
+ private static void validate(int hours, int minutes, int seconds) {
+ if (hours < -18 || hours > 18) {
+ throw new DateTimeException("Zone offset hours not in valid range: value " + hours +
+ " is not in the range -18 to 18");
+ }
+ if (hours > 0) {
+ if (minutes < 0 || seconds < 0) {
+ throw new DateTimeException("Zone offset minutes and seconds must be positive because hours is positive");
+ }
+ } else if (hours < 0) {
+ if (minutes > 0 || seconds > 0) {
+ throw new DateTimeException("Zone offset minutes and seconds must be negative because hours is negative");
+ }
+ } else if ((minutes > 0 && seconds < 0) || (minutes < 0 && seconds > 0)) {
+ throw new DateTimeException("Zone offset minutes and seconds must have the same sign");
+ }
+ if (Math.abs(minutes) > 59) {
+ throw new DateTimeException("Zone offset minutes not in valid range: abs(value) " +
+ Math.abs(minutes) + " is not in the range 0 to 59");
+ }
+ if (Math.abs(seconds) > 59) {
+ throw new DateTimeException("Zone offset seconds not in valid range: abs(value) " +
+ Math.abs(seconds) + " is not in the range 0 to 59");
+ }
+ if (Math.abs(hours) == 18 && (Math.abs(minutes) > 0 || Math.abs(seconds) > 0)) {
+ throw new DateTimeException("Zone offset not in valid range: -18:00 to +18:00");
+ }
+ }
+
+ /**
+ * Calculates the total offset in seconds.
+ *
+ * @param hours the time-zone offset in hours, from -18 to +18
+ * @param minutes the time-zone offset in minutes, from 0 to ±59, sign matches hours and seconds
+ * @param seconds the time-zone offset in seconds, from 0 to ±59, sign matches hours and minutes
+ * @return the total in seconds
+ */
+ private static int totalSeconds(int hours, int minutes, int seconds) {
+ return hours * SECONDS_PER_HOUR + minutes * SECONDS_PER_MINUTE + seconds;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Obtains an instance of {@code ZoneOffset} specifying the total offset in seconds
+ * <p>
+ * The offset must be in the range {@code -18:00} to {@code +18:00}, which corresponds to -64800 to +64800.
+ *
+ * @param totalSeconds the total time-zone offset in seconds, from -64800 to +64800
+ * @return the ZoneOffset, not null
+ * @throws DateTimeException if the offset is not in the required range
+ */
+ public static ZoneOffset ofTotalSeconds(int totalSeconds) {
+ if (Math.abs(totalSeconds) > MAX_SECONDS) {
+ throw new DateTimeException("Zone offset not in valid range: -18:00 to +18:00");
+ }
+ if (totalSeconds % (15 * SECONDS_PER_MINUTE) == 0) {
+ Integer totalSecs = totalSeconds;
+ ZoneOffset result = SECONDS_CACHE.get(totalSecs);
+ if (result == null) {
+ result = new ZoneOffset(totalSeconds);
+ SECONDS_CACHE.putIfAbsent(totalSecs, result);
+ result = SECONDS_CACHE.get(totalSecs);
+ ID_CACHE.putIfAbsent(result.getId(), result);
+ }
+ return result;
+ } else {
+ return new ZoneOffset(totalSeconds);
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Constructor.
+ *
+ * @param totalSeconds the total time-zone offset in seconds, from -64800 to +64800
+ */
+ private ZoneOffset(int totalSeconds) {
+ super();
+ this.totalSeconds = totalSeconds;
+ id = buildId(totalSeconds);
+ }
+
+ private static String buildId(int totalSeconds) {
+ if (totalSeconds == 0) {
+ return "Z";
+ } else {
+ int absTotalSeconds = Math.abs(totalSeconds);
+ StringBuilder buf = new StringBuilder();
+ int absHours = absTotalSeconds / SECONDS_PER_HOUR;
+ int absMinutes = (absTotalSeconds / SECONDS_PER_MINUTE) % MINUTES_PER_HOUR;
+ buf.append(totalSeconds < 0 ? "-" : "+")
+ .append(absHours < 10 ? "0" : "").append(absHours)
+ .append(absMinutes < 10 ? ":0" : ":").append(absMinutes);
+ int absSeconds = absTotalSeconds % SECONDS_PER_MINUTE;
+ if (absSeconds != 0) {
+ buf.append(absSeconds < 10 ? ":0" : ":").append(absSeconds);
+ }
+ return buf.toString();
+ }
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Gets the total zone offset in seconds.
+ * <p>
+ * This is the primary way to access the offset amount.
+ * It returns the total of the hours, minutes and seconds fields as a
+ * single offset that can be added to a time.
+ *
+ * @return the total zone offset amount in seconds
+ */
+ public int getTotalSeconds() {
+ return totalSeconds;
+ }
+
+ /**
+ * Gets the normalized zone offset ID.
+ * <p>
+ * The ID is minor variation to the standard ISO-8601 formatted string
+ * for the offset. There are three formats:
+ * <p><ul>
+ * <li>{@code Z} - for UTC (ISO-8601)
+ * <li>{@code +hh:mm} or {@code -hh:mm} - if the seconds are zero (ISO-8601)
+ * <li>{@code +hh:mm:ss} or {@code -hh:mm:ss} - if the seconds are non-zero (not ISO-8601)
+ * </ul><p>
+ *
+ * @return the zone offset ID, not null
+ */
+ @Override
+ public String getId() {
+ return id;
+ }
+
+ /**
+ * Gets the associated time-zone rules.
+ * <p>
+ * The rules will always return this offset when queried.
+ * The implementation class is immutable, thread-safe and serializable.
+ *
+ * @return the rules, not null
+ */
+ @Override
+ public ZoneRules getRules() {
+ return ZoneRules.of(this);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Checks if the specified field is supported.
+ * <p>
+ * This checks if this offset can be queried for the specified field.
+ * If false, then calling the {@link #range(TemporalField) range} and
+ * {@link #get(TemporalField) get} methods will throw an exception.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@code OFFSET_SECONDS} field returns true.
+ * All other {@code ChronoField} instances will return false.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.doIsSupported(TemporalAccessor)}
+ * passing {@code this} as the argument.
+ * Whether the field is supported is determined by the field.
+ *
+ * @param field the field to check, null returns false
+ * @return true if the field is supported on this offset, false if not
+ */
+ @Override
+ public boolean isSupported(TemporalField field) {
+ if (field instanceof ChronoField) {
+ return field == OFFSET_SECONDS;
+ }
+ return field != null && field.doIsSupported(this);
+ }
+
+ /**
+ * Gets the range of valid values for the specified field.
+ * <p>
+ * The range object expresses the minimum and maximum valid values for a field.
+ * This offset is used to enhance the accuracy of the returned range.
+ * If it is not possible to return the range, because the field is not supported
+ * or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@link #isSupported(TemporalField) supported fields} will return
+ * appropriate range instances.
+ * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.doRange(TemporalAccessor)}
+ * passing {@code this} as the argument.
+ * Whether the range can be obtained is determined by the field.
+ *
+ * @param field the field to query the range for, not null
+ * @return the range of valid values for the field, not null
+ * @throws DateTimeException if the range for the field cannot be obtained
+ */
+ @Override // override for Javadoc
+ public ValueRange range(TemporalField field) {
+ return TemporalAccessor.super.range(field);
+ }
+
+ /**
+ * Gets the value of the specified field from this offset as an {@code int}.
+ * <p>
+ * This queries this offset for the value for the specified field.
+ * The returned value will always be within the valid range of values for the field.
+ * If it is not possible to return the value, because the field is not supported
+ * or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@code OFFSET_SECONDS} field returns the value of the offset.
+ * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.doGet(TemporalAccessor)}
+ * passing {@code this} as the argument. Whether the value can be obtained,
+ * and what the value represents, is determined by the field.
+ *
+ * @param field the field to get, not null
+ * @return the value for the field
+ * @throws DateTimeException if a value for the field cannot be obtained
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override // override for Javadoc and performance
+ public int get(TemporalField field) {
+ if (field == OFFSET_SECONDS) {
+ return totalSeconds;
+ } else if (field instanceof ChronoField) {
+ throw new DateTimeException("Unsupported field: " + field.getName());
+ }
+ return range(field).checkValidIntValue(getLong(field), field);
+ }
+
+ /**
+ * Gets the value of the specified field from this offset as a {@code long}.
+ * <p>
+ * This queries this offset for the value for the specified field.
+ * If it is not possible to return the value, because the field is not supported
+ * or for some other reason, an exception is thrown.
+ * <p>
+ * If the field is a {@link ChronoField} then the query is implemented here.
+ * The {@code OFFSET_SECONDS} field returns the value of the offset.
+ * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
+ * <p>
+ * If the field is not a {@code ChronoField}, then the result of this method
+ * is obtained by invoking {@code TemporalField.doGet(TemporalAccessor)}
+ * passing {@code this} as the argument. Whether the value can be obtained,
+ * and what the value represents, is determined by the field.
+ *
+ * @param field the field to get, not null
+ * @return the value for the field
+ * @throws DateTimeException if a value for the field cannot be obtained
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public long getLong(TemporalField field) {
+ if (field == OFFSET_SECONDS) {
+ return totalSeconds;
+ } else if (field instanceof ChronoField) {
+ throw new DateTimeException("Unsupported field: " + field.getName());
+ }
+ return field.doGet(this);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Queries this offset using the specified query.
+ * <p>
+ * This queries this offset using the specified query strategy object.
+ * The {@code TemporalQuery} object defines the logic to be used to
+ * obtain the result. Read the documentation of the query to understand
+ * what the result of this method will be.
+ * <p>
+ * The result of this method is obtained by invoking the
+ * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
+ * specified query passing {@code this} as the argument.
+ *
+ * @param <R> the type of the result
+ * @param query the query to invoke, not null
+ * @return the query result, null may be returned (defined by the query)
+ * @throws DateTimeException if unable to query (defined by the query)
+ * @throws ArithmeticException if numeric overflow occurs (defined by the query)
+ */
+ @SuppressWarnings("unchecked")
+ @Override
+ public <R> R query(TemporalQuery<R> query) {
+ if (query == Queries.offset() || query == Queries.zone()) {
+ return (R) this;
+ }
+ return TemporalAccessor.super.query(query);
+ }
+
+ /**
+ * Adjusts the specified temporal object to have the same offset as this object.
+ * <p>
+ * This returns a temporal object of the same observable type as the input
+ * with the offset changed to be the same as this.
+ * <p>
+ * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
+ * passing {@link ChronoField#OFFSET_SECONDS} as the field.
+ * <p>
+ * In most cases, it is clearer to reverse the calling pattern by using
+ * {@link Temporal#with(TemporalAdjuster)}:
+ * <pre>
+ * // these two lines are equivalent, but the second approach is recommended
+ * temporal = thisOffset.adjustInto(temporal);
+ * temporal = temporal.with(thisOffset);
+ * </pre>
+ * <p>
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param temporal the target object to be adjusted, not null
+ * @return the adjusted object, not null
+ * @throws DateTimeException if unable to make the adjustment
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public Temporal adjustInto(Temporal temporal) {
+ return temporal.with(OFFSET_SECONDS, totalSeconds);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Compares this offset to another offset in descending order.
+ * <p>
+ * The offsets are compared in the order that they occur for the same time
+ * of day around the world. Thus, an offset of {@code +10:00} comes before an
+ * offset of {@code +09:00} and so on down to {@code -18:00}.
+ * <p>
+ * The comparison is "consistent with equals", as defined by {@link Comparable}.
+ *
+ * @param other the other date to compare to, not null
+ * @return the comparator value, negative if less, postive if greater
+ * @throws NullPointerException if {@code other} is null
+ */
+ @Override
+ public int compareTo(ZoneOffset other) {
+ return other.totalSeconds - totalSeconds;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Checks if this offset is equal to another offset.
+ * <p>
+ * The comparison is based on the amount of the offset in seconds.
+ * This is equivalent to a comparison by ID.
+ *
+ * @param obj the object to check, null returns false
+ * @return true if this is equal to the other offset
+ */
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj instanceof ZoneOffset) {
+ return totalSeconds == ((ZoneOffset) obj).totalSeconds;
+ }
+ return false;
+ }
+
+ /**
+ * A hash code for this offset.
+ *
+ * @return a suitable hash code
+ */
+ @Override
+ public int hashCode() {
+ return totalSeconds;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Outputs this offset as a {@code String}, using the normalized ID.
+ *
+ * @return a string representation of this offset, not null
+ */
+ @Override
+ public String toString() {
+ return id;
+ }
+
+ // -----------------------------------------------------------------------
+ /**
+ * Writes the object using a
+ * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
+ * <pre>
+ * out.writeByte(8); // identifies this as a ZoneOffset
+ * int offsetByte = totalSeconds % 900 == 0 ? totalSeconds / 900 : 127;
+ * out.writeByte(offsetByte);
+ * if (offsetByte == 127) {
+ * out.writeInt(totalSeconds);
+ * }
+ * </pre>
+ *
+ * @return the instance of {@code Ser}, not null
+ */
+ private Object writeReplace() {
+ return new Ser(Ser.ZONE_OFFSET_TYPE, this);
+ }
+
+ /**
+ * Defend against malicious streams.
+ * @return never
+ * @throws InvalidObjectException always
+ */
+ private Object readResolve() throws ObjectStreamException {
+ throw new InvalidObjectException("Deserialization via serialization delegate");
+ }
+
+ @Override
+ void write(DataOutput out) throws IOException {
+ out.writeByte(Ser.ZONE_OFFSET_TYPE);
+ writeExternal(out);
+ }
+
+ void writeExternal(DataOutput out) throws IOException {
+ final int offsetSecs = totalSeconds;
+ int offsetByte = offsetSecs % 900 == 0 ? offsetSecs / 900 : 127; // compress to -72 to +72
+ out.writeByte(offsetByte);
+ if (offsetByte == 127) {
+ out.writeInt(offsetSecs);
+ }
+ }
+
+ static ZoneOffset readExternal(DataInput in) throws IOException {
+ int offsetByte = in.readByte();
+ return (offsetByte == 127 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(offsetByte * 900));
+ }
+
+}