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   * Copyright (c) 2012, 2015, 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
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   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
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   *
   * 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
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   *
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  /*
   * 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
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   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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   * 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.LocalTime.MINUTES_PER_HOUR;
  import static java.time.LocalTime.SECONDS_PER_HOUR;
  import static java.time.LocalTime.SECONDS_PER_MINUTE;
  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.ObjectInputStream;
  import java.io.Serializable;
  import java.time.temporal.ChronoField;
  import java.time.temporal.Temporal;
  import java.time.temporal.TemporalAccessor;
  import java.time.temporal.TemporalAdjuster;
  import java.time.temporal.TemporalField;
  import java.time.temporal.TemporalQueries;
  import java.time.temporal.TemporalQuery;
  import java.time.temporal.UnsupportedTemporalTypeException;
  import java.time.temporal.ValueRange;
  import java.time.zone.ZoneRules;
  import java.util.Objects;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  
  // Android-changed: removed ValueBased paragraph.
  
  /**
   * A time-zone offset from Greenwich/UTC, such as {@code +02:00}.
   * <p>
   * A time-zone offset is the amount 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.
   *
   * @implSpec
   * 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 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:
       * <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>
       * Note that &plusmn; 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("Invalid ID for ZoneOffset, invalid format: " + offsetId);
          }
          char first = offsetId.charAt(0);
          if (first != '+' && first != '-') {
              throw new DateTimeException("Invalid ID for ZoneOffset, plus/minus not found when expected: " + offsetId);
          }
          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("Invalid ID for ZoneOffset, colon not found when expected: " + offsetId);
          }
          char ch1 = offsetId.charAt(pos);
          char ch2 = offsetId.charAt(pos + 1);
          if (ch1 < '0' || ch1 > '9' || ch2 < '0' || ch2 > '9') {
              throw new DateTimeException("Invalid ID for ZoneOffset, non numeric characters found: " + offsetId);
          }
          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 &plusmn;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 &plusmn;59, sign matches hours and seconds
       * @param seconds  the time-zone offset in seconds, from 0 to &plusmn;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>
       * This obtains an offset 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 ZoneOffset}.
       * <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 uses the {@link TemporalQueries#offset()} query, which relies
       * on extracting 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 as a query 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) {
          Objects.requireNonNull(temporal, "temporal");
          ZoneOffset offset = temporal.query(TemporalQueries.offset());
          if (offset == null) {
              throw new DateTimeException("Unable to obtain ZoneOffset from TemporalAccessor: " +
                      temporal + " of type " + temporal.getClass().getName());
          }
          return offset;
      }
  
      //-----------------------------------------------------------------------
      /**
       * 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 &plusmn;59
       * @param seconds  the time-zone offset in seconds, from 0 to &plusmn;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 &plusmn;59, sign matches hours and seconds
       * @param seconds  the time-zone offset in seconds, from 0 to &plusmn;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:
       * <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>
       *
       * @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.isSupportedBy(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.isSupportedBy(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 an {@code UnsupportedTemporalTypeException}.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.rangeRefinedBy(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
       * @throws UnsupportedTemporalTypeException if the field is not supported
       */
      @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 of 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 an {@code UnsupportedTemporalTypeException}.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.getFrom(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 or
       *         the value is outside the range of valid values for the field
       * @throws UnsupportedTemporalTypeException if the field is not supported or
       *         the range of values exceeds an {@code int}
       * @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 UnsupportedTemporalTypeException("Unsupported field: " + field);
          }
          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 of 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 an {@code UnsupportedTemporalTypeException}.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.getFrom(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 UnsupportedTemporalTypeException if the field is not supported
       * @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 UnsupportedTemporalTypeException("Unsupported field: " + field);
          }
          return field.getFrom(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 == TemporalQueries.offset() || query == TemporalQueries.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>.
       * @serialData
       * <pre>
       *  out.writeByte(8);                  // identifies 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.
       *
       * @param s the stream to read
       * @throws InvalidObjectException always
       */
      private void readObject(ObjectInputStream s) throws InvalidObjectException {
          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));
      }
  
  }
  