jdk/src/share/classes/java/time/temporal/MonthDay.java
changeset 15658 55b829ca2334
parent 15657 c588664d547e
child 15659 e575dab44ff5
equal deleted inserted replaced
15657:c588664d547e 15658:55b829ca2334
     1 /*
       
     2  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
       
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     4  *
       
     5  * This code is free software; you can redistribute it and/or modify it
       
     6  * under the terms of the GNU General Public License version 2 only, as
       
     7  * published by the Free Software Foundation.  Oracle designates this
       
     8  * particular file as subject to the "Classpath" exception as provided
       
     9  * by Oracle in the LICENSE file that accompanied this code.
       
    10  *
       
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    14  * version 2 for more details (a copy is included in the LICENSE file that
       
    15  * accompanied this code).
       
    16  *
       
    17  * You should have received a copy of the GNU General Public License version
       
    18  * 2 along with this work; if not, write to the Free Software Foundation,
       
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    20  *
       
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
       
    22  * or visit www.oracle.com if you need additional information or have any
       
    23  * questions.
       
    24  */
       
    25 
       
    26 /*
       
    27  * This file is available under and governed by the GNU General Public
       
    28  * License version 2 only, as published by the Free Software Foundation.
       
    29  * However, the following notice accompanied the original version of this
       
    30  * file:
       
    31  *
       
    32  * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
       
    33  *
       
    34  * All rights reserved.
       
    35  *
       
    36  * Redistribution and use in source and binary forms, with or without
       
    37  * modification, are permitted provided that the following conditions are met:
       
    38  *
       
    39  *  * Redistributions of source code must retain the above copyright notice,
       
    40  *    this list of conditions and the following disclaimer.
       
    41  *
       
    42  *  * Redistributions in binary form must reproduce the above copyright notice,
       
    43  *    this list of conditions and the following disclaimer in the documentation
       
    44  *    and/or other materials provided with the distribution.
       
    45  *
       
    46  *  * Neither the name of JSR-310 nor the names of its contributors
       
    47  *    may be used to endorse or promote products derived from this software
       
    48  *    without specific prior written permission.
       
    49  *
       
    50  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
       
    51  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
       
    52  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
       
    53  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
       
    54  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
       
    55  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
       
    56  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
       
    57  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
       
    58  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
       
    59  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
       
    60  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
       
    61  */
       
    62 package java.time.temporal;
       
    63 
       
    64 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
       
    65 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
       
    66 
       
    67 import java.io.DataInput;
       
    68 import java.io.DataOutput;
       
    69 import java.io.IOException;
       
    70 import java.io.InvalidObjectException;
       
    71 import java.io.ObjectStreamException;
       
    72 import java.io.Serializable;
       
    73 import java.time.Clock;
       
    74 import java.time.DateTimeException;
       
    75 import java.time.LocalDate;
       
    76 import java.time.Month;
       
    77 import java.time.ZoneId;
       
    78 import java.time.format.DateTimeFormatter;
       
    79 import java.time.format.DateTimeFormatterBuilder;
       
    80 import java.time.format.DateTimeParseException;
       
    81 import java.util.Objects;
       
    82 
       
    83 /**
       
    84  * A month-day in the ISO-8601 calendar system, such as {@code --12-03}.
       
    85  * <p>
       
    86  * {@code MonthDay} is an immutable date-time object that represents the combination
       
    87  * of a year and month. Any field that can be derived from a month and day, such as
       
    88  * quarter-of-year, can be obtained.
       
    89  * <p>
       
    90  * This class does not store or represent a year, time or time-zone.
       
    91  * For example, the value "December 3rd" can be stored in a {@code MonthDay}.
       
    92  * <p>
       
    93  * Since a {@code MonthDay} does not possess a year, the leap day of
       
    94  * February 29th is considered valid.
       
    95  * <p>
       
    96  * This class implements {@link TemporalAccessor} rather than {@link Temporal}.
       
    97  * This is because it is not possible to define whether February 29th is valid or not
       
    98  * without external information, preventing the implementation of plus/minus.
       
    99  * Related to this, {@code MonthDay} only provides access to query and set the fields
       
   100  * {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH}.
       
   101  * <p>
       
   102  * The ISO-8601 calendar system is the modern civil calendar system used today
       
   103  * in most of the world. It is equivalent to the proleptic Gregorian calendar
       
   104  * system, in which today's rules for leap years are applied for all time.
       
   105  * For most applications written today, the ISO-8601 rules are entirely suitable.
       
   106  * However, any application that makes use of historical dates, and requires them
       
   107  * to be accurate will find the ISO-8601 approach unsuitable.
       
   108  *
       
   109  * <h3>Specification for implementors</h3>
       
   110  * This class is immutable and thread-safe.
       
   111  *
       
   112  * @since 1.8
       
   113  */
       
   114 public final class MonthDay
       
   115         implements TemporalAccessor, TemporalAdjuster, Comparable<MonthDay>, Serializable {
       
   116 
       
   117     /**
       
   118      * Serialization version.
       
   119      */
       
   120     private static final long serialVersionUID = -939150713474957432L;
       
   121     /**
       
   122      * Parser.
       
   123      */
       
   124     private static final DateTimeFormatter PARSER = new DateTimeFormatterBuilder()
       
   125         .appendLiteral("--")
       
   126         .appendValue(MONTH_OF_YEAR, 2)
       
   127         .appendLiteral('-')
       
   128         .appendValue(DAY_OF_MONTH, 2)
       
   129         .toFormatter();
       
   130 
       
   131     /**
       
   132      * The month-of-year, not null.
       
   133      */
       
   134     private final int month;
       
   135     /**
       
   136      * The day-of-month.
       
   137      */
       
   138     private final int day;
       
   139 
       
   140     //-----------------------------------------------------------------------
       
   141     /**
       
   142      * Obtains the current month-day from the system clock in the default time-zone.
       
   143      * <p>
       
   144      * This will query the {@link java.time.Clock#systemDefaultZone() system clock} in the default
       
   145      * time-zone to obtain the current month-day.
       
   146      * <p>
       
   147      * Using this method will prevent the ability to use an alternate clock for testing
       
   148      * because the clock is hard-coded.
       
   149      *
       
   150      * @return the current month-day using the system clock and default time-zone, not null
       
   151      */
       
   152     public static MonthDay now() {
       
   153         return now(Clock.systemDefaultZone());
       
   154     }
       
   155 
       
   156     /**
       
   157      * Obtains the current month-day from the system clock in the specified time-zone.
       
   158      * <p>
       
   159      * This will query the {@link Clock#system(java.time.ZoneId) system clock} to obtain the current month-day.
       
   160      * Specifying the time-zone avoids dependence on the default time-zone.
       
   161      * <p>
       
   162      * Using this method will prevent the ability to use an alternate clock for testing
       
   163      * because the clock is hard-coded.
       
   164      *
       
   165      * @param zone  the zone ID to use, not null
       
   166      * @return the current month-day using the system clock, not null
       
   167      */
       
   168     public static MonthDay now(ZoneId zone) {
       
   169         return now(Clock.system(zone));
       
   170     }
       
   171 
       
   172     /**
       
   173      * Obtains the current month-day from the specified clock.
       
   174      * <p>
       
   175      * This will query the specified clock to obtain the current month-day.
       
   176      * Using this method allows the use of an alternate clock for testing.
       
   177      * The alternate clock may be introduced using {@link Clock dependency injection}.
       
   178      *
       
   179      * @param clock  the clock to use, not null
       
   180      * @return the current month-day, not null
       
   181      */
       
   182     public static MonthDay now(Clock clock) {
       
   183         final LocalDate now = LocalDate.now(clock);  // called once
       
   184         return MonthDay.of(now.getMonth(), now.getDayOfMonth());
       
   185     }
       
   186 
       
   187     //-----------------------------------------------------------------------
       
   188     /**
       
   189      * Obtains an instance of {@code MonthDay}.
       
   190      * <p>
       
   191      * The day-of-month must be valid for the month within a leap year.
       
   192      * Hence, for February, day 29 is valid.
       
   193      * <p>
       
   194      * For example, passing in April and day 31 will throw an exception, as
       
   195      * there can never be April 31st in any year. By contrast, passing in
       
   196      * February 29th is permitted, as that month-day can sometimes be valid.
       
   197      *
       
   198      * @param month  the month-of-year to represent, not null
       
   199      * @param dayOfMonth  the day-of-month to represent, from 1 to 31
       
   200      * @return the month-day, not null
       
   201      * @throws DateTimeException if the value of any field is out of range
       
   202      * @throws DateTimeException if the day-of-month is invalid for the month
       
   203      */
       
   204     public static MonthDay of(Month month, int dayOfMonth) {
       
   205         Objects.requireNonNull(month, "month");
       
   206         DAY_OF_MONTH.checkValidValue(dayOfMonth);
       
   207         if (dayOfMonth > month.maxLength()) {
       
   208             throw new DateTimeException("Illegal value for DayOfMonth field, value " + dayOfMonth +
       
   209                     " is not valid for month " + month.name());
       
   210         }
       
   211         return new MonthDay(month.getValue(), dayOfMonth);
       
   212     }
       
   213 
       
   214     /**
       
   215      * Obtains an instance of {@code MonthDay}.
       
   216      * <p>
       
   217      * The day-of-month must be valid for the month within a leap year.
       
   218      * Hence, for month 2 (February), day 29 is valid.
       
   219      * <p>
       
   220      * For example, passing in month 4 (April) and day 31 will throw an exception, as
       
   221      * there can never be April 31st in any year. By contrast, passing in
       
   222      * February 29th is permitted, as that month-day can sometimes be valid.
       
   223      *
       
   224      * @param month  the month-of-year to represent, from 1 (January) to 12 (December)
       
   225      * @param dayOfMonth  the day-of-month to represent, from 1 to 31
       
   226      * @return the month-day, not null
       
   227      * @throws DateTimeException if the value of any field is out of range
       
   228      * @throws DateTimeException if the day-of-month is invalid for the month
       
   229      */
       
   230     public static MonthDay of(int month, int dayOfMonth) {
       
   231         return of(Month.of(month), dayOfMonth);
       
   232     }
       
   233 
       
   234     //-----------------------------------------------------------------------
       
   235     /**
       
   236      * Obtains an instance of {@code MonthDay} from a temporal object.
       
   237      * <p>
       
   238      * A {@code TemporalAccessor} represents some form of date and time information.
       
   239      * This factory converts the arbitrary temporal object to an instance of {@code MonthDay}.
       
   240      * <p>
       
   241      * The conversion extracts the {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} and
       
   242      * {@link ChronoField#DAY_OF_MONTH DAY_OF_MONTH} fields.
       
   243      * The extraction is only permitted if the date-time has an ISO chronology.
       
   244      * <p>
       
   245      * This method matches the signature of the functional interface {@link TemporalQuery}
       
   246      * allowing it to be used in queries via method reference, {@code MonthDay::from}.
       
   247      *
       
   248      * @param temporal  the temporal object to convert, not null
       
   249      * @return the month-day, not null
       
   250      * @throws DateTimeException if unable to convert to a {@code MonthDay}
       
   251      */
       
   252     public static MonthDay from(TemporalAccessor temporal) {
       
   253         if (temporal instanceof MonthDay) {
       
   254             return (MonthDay) temporal;
       
   255         }
       
   256         try {
       
   257             if (ISOChrono.INSTANCE.equals(Chrono.from(temporal)) == false) {
       
   258                 temporal = LocalDate.from(temporal);
       
   259             }
       
   260             return of(temporal.get(MONTH_OF_YEAR), temporal.get(DAY_OF_MONTH));
       
   261         } catch (DateTimeException ex) {
       
   262             throw new DateTimeException("Unable to obtain MonthDay from TemporalAccessor: " + temporal.getClass(), ex);
       
   263         }
       
   264     }
       
   265 
       
   266     //-----------------------------------------------------------------------
       
   267     /**
       
   268      * Obtains an instance of {@code MonthDay} from a text string such as {@code --12-03}.
       
   269      * <p>
       
   270      * The string must represent a valid month-day.
       
   271      * The format is {@code --MM-dd}.
       
   272      *
       
   273      * @param text  the text to parse such as "--12-03", not null
       
   274      * @return the parsed month-day, not null
       
   275      * @throws DateTimeParseException if the text cannot be parsed
       
   276      */
       
   277     public static MonthDay parse(CharSequence text) {
       
   278         return parse(text, PARSER);
       
   279     }
       
   280 
       
   281     /**
       
   282      * Obtains an instance of {@code MonthDay} from a text string using a specific formatter.
       
   283      * <p>
       
   284      * The text is parsed using the formatter, returning a month-day.
       
   285      *
       
   286      * @param text  the text to parse, not null
       
   287      * @param formatter  the formatter to use, not null
       
   288      * @return the parsed month-day, not null
       
   289      * @throws DateTimeParseException if the text cannot be parsed
       
   290      */
       
   291     public static MonthDay parse(CharSequence text, DateTimeFormatter formatter) {
       
   292         Objects.requireNonNull(formatter, "formatter");
       
   293         return formatter.parse(text, MonthDay::from);
       
   294     }
       
   295 
       
   296     //-----------------------------------------------------------------------
       
   297     /**
       
   298      * Constructor, previously validated.
       
   299      *
       
   300      * @param month  the month-of-year to represent, validated from 1 to 12
       
   301      * @param dayOfMonth  the day-of-month to represent, validated from 1 to 29-31
       
   302      */
       
   303     private MonthDay(int month, int dayOfMonth) {
       
   304         this.month = month;
       
   305         this.day = dayOfMonth;
       
   306     }
       
   307 
       
   308     //-----------------------------------------------------------------------
       
   309     /**
       
   310      * Checks if the specified field is supported.
       
   311      * <p>
       
   312      * This checks if this month-day can be queried for the specified field.
       
   313      * If false, then calling the {@link #range(TemporalField) range} and
       
   314      * {@link #get(TemporalField) get} methods will throw an exception.
       
   315      * <p>
       
   316      * If the field is a {@link ChronoField} then the query is implemented here.
       
   317      * The {@link #isSupported(TemporalField) supported fields} will return valid
       
   318      * values based on this date-time.
       
   319      * The supported fields are:
       
   320      * <ul>
       
   321      * <li>{@code MONTH_OF_YEAR}
       
   322      * <li>{@code YEAR}
       
   323      * </ul>
       
   324      * All other {@code ChronoField} instances will return false.
       
   325      * <p>
       
   326      * If the field is not a {@code ChronoField}, then the result of this method
       
   327      * is obtained by invoking {@code TemporalField.doIsSupported(TemporalAccessor)}
       
   328      * passing {@code this} as the argument.
       
   329      * Whether the field is supported is determined by the field.
       
   330      *
       
   331      * @param field  the field to check, null returns false
       
   332      * @return true if the field is supported on this month-day, false if not
       
   333      */
       
   334     @Override
       
   335     public boolean isSupported(TemporalField field) {
       
   336         if (field instanceof ChronoField) {
       
   337             return field == MONTH_OF_YEAR || field == DAY_OF_MONTH;
       
   338         }
       
   339         return field != null && field.doIsSupported(this);
       
   340     }
       
   341 
       
   342     /**
       
   343      * Gets the range of valid values for the specified field.
       
   344      * <p>
       
   345      * The range object expresses the minimum and maximum valid values for a field.
       
   346      * This month-day is used to enhance the accuracy of the returned range.
       
   347      * If it is not possible to return the range, because the field is not supported
       
   348      * or for some other reason, an exception is thrown.
       
   349      * <p>
       
   350      * If the field is a {@link ChronoField} then the query is implemented here.
       
   351      * The {@link #isSupported(TemporalField) supported fields} will return
       
   352      * appropriate range instances.
       
   353      * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
       
   354      * <p>
       
   355      * If the field is not a {@code ChronoField}, then the result of this method
       
   356      * is obtained by invoking {@code TemporalField.doRange(TemporalAccessor)}
       
   357      * passing {@code this} as the argument.
       
   358      * Whether the range can be obtained is determined by the field.
       
   359      *
       
   360      * @param field  the field to query the range for, not null
       
   361      * @return the range of valid values for the field, not null
       
   362      * @throws DateTimeException if the range for the field cannot be obtained
       
   363      */
       
   364     @Override
       
   365     public ValueRange range(TemporalField field) {
       
   366         if (field == MONTH_OF_YEAR) {
       
   367             return field.range();
       
   368         } else if (field == DAY_OF_MONTH) {
       
   369             return ValueRange.of(1, getMonth().minLength(), getMonth().maxLength());
       
   370         }
       
   371         return TemporalAccessor.super.range(field);
       
   372     }
       
   373 
       
   374     /**
       
   375      * Gets the value of the specified field from this month-day as an {@code int}.
       
   376      * <p>
       
   377      * This queries this month-day for the value for the specified field.
       
   378      * The returned value will always be within the valid range of values for the field.
       
   379      * If it is not possible to return the value, because the field is not supported
       
   380      * or for some other reason, an exception is thrown.
       
   381      * <p>
       
   382      * If the field is a {@link ChronoField} then the query is implemented here.
       
   383      * The {@link #isSupported(TemporalField) supported fields} will return valid
       
   384      * values based on this month-day.
       
   385      * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
       
   386      * <p>
       
   387      * If the field is not a {@code ChronoField}, then the result of this method
       
   388      * is obtained by invoking {@code TemporalField.doGet(TemporalAccessor)}
       
   389      * passing {@code this} as the argument. Whether the value can be obtained,
       
   390      * and what the value represents, is determined by the field.
       
   391      *
       
   392      * @param field  the field to get, not null
       
   393      * @return the value for the field
       
   394      * @throws DateTimeException if a value for the field cannot be obtained
       
   395      * @throws ArithmeticException if numeric overflow occurs
       
   396      */
       
   397     @Override  // override for Javadoc
       
   398     public int get(TemporalField field) {
       
   399         return range(field).checkValidIntValue(getLong(field), field);
       
   400     }
       
   401 
       
   402     /**
       
   403      * Gets the value of the specified field from this month-day as a {@code long}.
       
   404      * <p>
       
   405      * This queries this month-day for the value for the specified field.
       
   406      * If it is not possible to return the value, because the field is not supported
       
   407      * or for some other reason, an exception is thrown.
       
   408      * <p>
       
   409      * If the field is a {@link ChronoField} then the query is implemented here.
       
   410      * The {@link #isSupported(TemporalField) supported fields} will return valid
       
   411      * values based on this month-day.
       
   412      * All other {@code ChronoField} instances will throw a {@code DateTimeException}.
       
   413      * <p>
       
   414      * If the field is not a {@code ChronoField}, then the result of this method
       
   415      * is obtained by invoking {@code TemporalField.doGet(TemporalAccessor)}
       
   416      * passing {@code this} as the argument. Whether the value can be obtained,
       
   417      * and what the value represents, is determined by the field.
       
   418      *
       
   419      * @param field  the field to get, not null
       
   420      * @return the value for the field
       
   421      * @throws DateTimeException if a value for the field cannot be obtained
       
   422      * @throws ArithmeticException if numeric overflow occurs
       
   423      */
       
   424     @Override
       
   425     public long getLong(TemporalField field) {
       
   426         if (field instanceof ChronoField) {
       
   427             switch ((ChronoField) field) {
       
   428                 // alignedDOW and alignedWOM not supported because they cannot be set in with()
       
   429                 case DAY_OF_MONTH: return day;
       
   430                 case MONTH_OF_YEAR: return month;
       
   431             }
       
   432             throw new DateTimeException("Unsupported field: " + field.getName());
       
   433         }
       
   434         return field.doGet(this);
       
   435     }
       
   436 
       
   437     //-----------------------------------------------------------------------
       
   438     /**
       
   439      * Gets the month-of-year field using the {@code Month} enum.
       
   440      * <p>
       
   441      * This method returns the enum {@link Month} for the month.
       
   442      * This avoids confusion as to what {@code int} values mean.
       
   443      * If you need access to the primitive {@code int} value then the enum
       
   444      * provides the {@link Month#getValue() int value}.
       
   445      *
       
   446      * @return the month-of-year, not null
       
   447      */
       
   448     public Month getMonth() {
       
   449         return Month.of(month);
       
   450     }
       
   451 
       
   452     /**
       
   453      * Gets the day-of-month field.
       
   454      * <p>
       
   455      * This method returns the primitive {@code int} value for the day-of-month.
       
   456      *
       
   457      * @return the day-of-month, from 1 to 31
       
   458      */
       
   459     public int getDayOfMonth() {
       
   460         return day;
       
   461     }
       
   462 
       
   463     //-----------------------------------------------------------------------
       
   464     /**
       
   465      * Checks if the year is valid for this month-day.
       
   466      * <p>
       
   467      * This method checks whether this month and day and the input year form
       
   468      * a valid date. This can only return false for February 29th.
       
   469      *
       
   470      * @param year  the year to validate, an out of range value returns false
       
   471      * @return true if the year is valid for this month-day
       
   472      * @see Year#isValidMonthDay(MonthDay)
       
   473      */
       
   474     public boolean isValidYear(int year) {
       
   475         return (day == 29 && month == 2 && Year.isLeap(year) == false) == false;
       
   476     }
       
   477 
       
   478     //-----------------------------------------------------------------------
       
   479     /**
       
   480      * Returns a copy of this {@code MonthDay} with the month-of-year altered.
       
   481      * <p>
       
   482      * This returns a month-day with the specified month.
       
   483      * If the day-of-month is invalid for the specified month, the day will
       
   484      * be adjusted to the last valid day-of-month.
       
   485      * <p>
       
   486      * This instance is immutable and unaffected by this method call.
       
   487      *
       
   488      * @param month  the month-of-year to set in the returned month-day, from 1 (January) to 12 (December)
       
   489      * @return a {@code MonthDay} based on this month-day with the requested month, not null
       
   490      * @throws DateTimeException if the month-of-year value is invalid
       
   491      */
       
   492     public MonthDay withMonth(int month) {
       
   493         return with(Month.of(month));
       
   494     }
       
   495 
       
   496     /**
       
   497      * Returns a copy of this {@code MonthDay} with the month-of-year altered.
       
   498      * <p>
       
   499      * This returns a month-day with the specified month.
       
   500      * If the day-of-month is invalid for the specified month, the day will
       
   501      * be adjusted to the last valid day-of-month.
       
   502      * <p>
       
   503      * This instance is immutable and unaffected by this method call.
       
   504      *
       
   505      * @param month  the month-of-year to set in the returned month-day, not null
       
   506      * @return a {@code MonthDay} based on this month-day with the requested month, not null
       
   507      */
       
   508     public MonthDay with(Month month) {
       
   509         Objects.requireNonNull(month, "month");
       
   510         if (month.getValue() == this.month) {
       
   511             return this;
       
   512         }
       
   513         int day = Math.min(this.day, month.maxLength());
       
   514         return new MonthDay(month.getValue(), day);
       
   515     }
       
   516 
       
   517     /**
       
   518      * Returns a copy of this {@code MonthDay} with the day-of-month altered.
       
   519      * <p>
       
   520      * This returns a month-day with the specified day-of-month.
       
   521      * If the day-of-month is invalid for the month, an exception is thrown.
       
   522      * <p>
       
   523      * This instance is immutable and unaffected by this method call.
       
   524      *
       
   525      * @param dayOfMonth  the day-of-month to set in the return month-day, from 1 to 31
       
   526      * @return a {@code MonthDay} based on this month-day with the requested day, not null
       
   527      * @throws DateTimeException if the day-of-month value is invalid
       
   528      * @throws DateTimeException if the day-of-month is invalid for the month
       
   529      */
       
   530     public MonthDay withDayOfMonth(int dayOfMonth) {
       
   531         if (dayOfMonth == this.day) {
       
   532             return this;
       
   533         }
       
   534         return of(month, dayOfMonth);
       
   535     }
       
   536 
       
   537     //-----------------------------------------------------------------------
       
   538     /**
       
   539      * Queries this month-day using the specified query.
       
   540      * <p>
       
   541      * This queries this month-day using the specified query strategy object.
       
   542      * The {@code TemporalQuery} object defines the logic to be used to
       
   543      * obtain the result. Read the documentation of the query to understand
       
   544      * what the result of this method will be.
       
   545      * <p>
       
   546      * The result of this method is obtained by invoking the
       
   547      * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
       
   548      * specified query passing {@code this} as the argument.
       
   549      *
       
   550      * @param <R> the type of the result
       
   551      * @param query  the query to invoke, not null
       
   552      * @return the query result, null may be returned (defined by the query)
       
   553      * @throws DateTimeException if unable to query (defined by the query)
       
   554      * @throws ArithmeticException if numeric overflow occurs (defined by the query)
       
   555      */
       
   556     @SuppressWarnings("unchecked")
       
   557     @Override
       
   558     public <R> R query(TemporalQuery<R> query) {
       
   559         if (query == Queries.chrono()) {
       
   560             return (R) ISOChrono.INSTANCE;
       
   561         }
       
   562         return TemporalAccessor.super.query(query);
       
   563     }
       
   564 
       
   565     /**
       
   566      * Adjusts the specified temporal object to have this month-day.
       
   567      * <p>
       
   568      * This returns a temporal object of the same observable type as the input
       
   569      * with the month and day-of-month changed to be the same as this.
       
   570      * <p>
       
   571      * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
       
   572      * twice, passing {@link ChronoField#MONTH_OF_YEAR} and
       
   573      * {@link ChronoField#DAY_OF_MONTH} as the fields.
       
   574      * If the specified temporal object does not use the ISO calendar system then
       
   575      * a {@code DateTimeException} is thrown.
       
   576      * <p>
       
   577      * In most cases, it is clearer to reverse the calling pattern by using
       
   578      * {@link Temporal#with(TemporalAdjuster)}:
       
   579      * <pre>
       
   580      *   // these two lines are equivalent, but the second approach is recommended
       
   581      *   temporal = thisMonthDay.adjustInto(temporal);
       
   582      *   temporal = temporal.with(thisMonthDay);
       
   583      * </pre>
       
   584      * <p>
       
   585      * This instance is immutable and unaffected by this method call.
       
   586      *
       
   587      * @param temporal  the target object to be adjusted, not null
       
   588      * @return the adjusted object, not null
       
   589      * @throws DateTimeException if unable to make the adjustment
       
   590      * @throws ArithmeticException if numeric overflow occurs
       
   591      */
       
   592     @Override
       
   593     public Temporal adjustInto(Temporal temporal) {
       
   594         if (Chrono.from(temporal).equals(ISOChrono.INSTANCE) == false) {
       
   595             throw new DateTimeException("Adjustment only supported on ISO date-time");
       
   596         }
       
   597         temporal = temporal.with(MONTH_OF_YEAR, month);
       
   598         return temporal.with(DAY_OF_MONTH, Math.min(temporal.range(DAY_OF_MONTH).getMaximum(), day));
       
   599     }
       
   600 
       
   601     //-----------------------------------------------------------------------
       
   602     /**
       
   603      * Returns a date formed from this month-day at the specified year.
       
   604      * <p>
       
   605      * This combines this month-day and the specified year to form a {@code LocalDate}.
       
   606      * A month-day of February 29th will be adjusted to February 28th in the resulting
       
   607      * date if the year is not a leap year.
       
   608      * <p>
       
   609      * This instance is immutable and unaffected by this method call.
       
   610      *
       
   611      * @param year  the year to use, from MIN_YEAR to MAX_YEAR
       
   612      * @return the local date formed from this month-day and the specified year, not null
       
   613      * @see Year#atMonthDay(MonthDay)
       
   614      */
       
   615     public LocalDate atYear(int year) {
       
   616         return LocalDate.of(year, month, isValidYear(year) ? day : 28);
       
   617     }
       
   618 
       
   619     //-----------------------------------------------------------------------
       
   620     /**
       
   621      * Compares this month-day to another month-day.
       
   622      * <p>
       
   623      * The comparison is based first on value of the month, then on the value of the day.
       
   624      * It is "consistent with equals", as defined by {@link Comparable}.
       
   625      *
       
   626      * @param other  the other month-day to compare to, not null
       
   627      * @return the comparator value, negative if less, positive if greater
       
   628      */
       
   629     public int compareTo(MonthDay other) {
       
   630         int cmp = (month - other.month);
       
   631         if (cmp == 0) {
       
   632             cmp = (day - other.day);
       
   633         }
       
   634         return cmp;
       
   635     }
       
   636 
       
   637     /**
       
   638      * Is this month-day after the specified month-day.
       
   639      *
       
   640      * @param other  the other month-day to compare to, not null
       
   641      * @return true if this is after the specified month-day
       
   642      */
       
   643     public boolean isAfter(MonthDay other) {
       
   644         return compareTo(other) > 0;
       
   645     }
       
   646 
       
   647     /**
       
   648      * Is this month-day before the specified month-day.
       
   649      *
       
   650      * @param other  the other month-day to compare to, not null
       
   651      * @return true if this point is before the specified month-day
       
   652      */
       
   653     public boolean isBefore(MonthDay other) {
       
   654         return compareTo(other) < 0;
       
   655     }
       
   656 
       
   657     //-----------------------------------------------------------------------
       
   658     /**
       
   659      * Checks if this month-day is equal to another month-day.
       
   660      * <p>
       
   661      * The comparison is based on the time-line position of the month-day within a year.
       
   662      *
       
   663      * @param obj  the object to check, null returns false
       
   664      * @return true if this is equal to the other month-day
       
   665      */
       
   666     @Override
       
   667     public boolean equals(Object obj) {
       
   668         if (this == obj) {
       
   669             return true;
       
   670         }
       
   671         if (obj instanceof MonthDay) {
       
   672             MonthDay other = (MonthDay) obj;
       
   673             return month == other.month && day == other.day;
       
   674         }
       
   675         return false;
       
   676     }
       
   677 
       
   678     /**
       
   679      * A hash code for this month-day.
       
   680      *
       
   681      * @return a suitable hash code
       
   682      */
       
   683     @Override
       
   684     public int hashCode() {
       
   685         return (month << 6) + day;
       
   686     }
       
   687 
       
   688     //-----------------------------------------------------------------------
       
   689     /**
       
   690      * Outputs this month-day as a {@code String}, such as {@code --12-03}.
       
   691      * <p>
       
   692      * The output will be in the format {@code --MM-dd}:
       
   693      *
       
   694      * @return a string representation of this month-day, not null
       
   695      */
       
   696     @Override
       
   697     public String toString() {
       
   698         return new StringBuilder(10).append("--")
       
   699             .append(month < 10 ? "0" : "").append(month)
       
   700             .append(day < 10 ? "-0" : "-").append(day)
       
   701             .toString();
       
   702     }
       
   703 
       
   704     /**
       
   705      * Outputs this month-day as a {@code String} using the formatter.
       
   706      * <p>
       
   707      * This month-day will be passed to the formatter
       
   708      * {@link DateTimeFormatter#print(TemporalAccessor) print method}.
       
   709      *
       
   710      * @param formatter  the formatter to use, not null
       
   711      * @return the formatted month-day string, not null
       
   712      * @throws DateTimeException if an error occurs during printing
       
   713      */
       
   714     public String toString(DateTimeFormatter formatter) {
       
   715         Objects.requireNonNull(formatter, "formatter");
       
   716         return formatter.print(this);
       
   717     }
       
   718 
       
   719     //-----------------------------------------------------------------------
       
   720     /**
       
   721      * Writes the object using a
       
   722      * <a href="../../../serialized-form.html#java.time.temporal.Ser">dedicated serialized form</a>.
       
   723      * <pre>
       
   724      *  out.writeByte(6);  // identifies this as a Year
       
   725      *  out.writeByte(month);
       
   726      *  out.writeByte(day);
       
   727      * </pre>
       
   728      *
       
   729      * @return the instance of {@code Ser}, not null
       
   730      */
       
   731     private Object writeReplace() {
       
   732         return new Ser(Ser.MONTH_DAY_TYPE, this);
       
   733     }
       
   734 
       
   735     /**
       
   736      * Defend against malicious streams.
       
   737      * @return never
       
   738      * @throws InvalidObjectException always
       
   739      */
       
   740     private Object readResolve() throws ObjectStreamException {
       
   741         throw new InvalidObjectException("Deserialization via serialization delegate");
       
   742     }
       
   743 
       
   744     void writeExternal(DataOutput out) throws IOException {
       
   745         out.writeByte(month);
       
   746         out.writeByte(day);
       
   747     }
       
   748 
       
   749     static MonthDay readExternal(DataInput in) throws IOException {
       
   750         byte month = in.readByte();
       
   751         byte day = in.readByte();
       
   752         return MonthDay.of(month, day);
       
   753     }
       
   754 
       
   755 }