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/*
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* Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
*
* All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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package java.time;
import static java.time.temporal.
ChronoField.
DAY_OF_MONTH;
import static java.time.temporal.
ChronoField.
MONTH_OF_YEAR;
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.chrono.
Chronology;
import java.time.chrono.
IsoChronology;
import java.time.format.
DateTimeFormatter;
import java.time.format.
DateTimeFormatterBuilder;
import java.time.format.
DateTimeParseException;
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.util.
Objects;
/**
* A month-day in the ISO-8601 calendar system, such as {@code --12-03}.
* <p>
* {@code MonthDay} is an immutable date-time object that represents the combination
* of a month and day-of-month. Any field that can be derived from a month and day,
* such as quarter-of-year, can be obtained.
* <p>
* This class does not store or represent a year, time or time-zone.
* For example, the value "December 3rd" can be stored in a {@code MonthDay}.
* <p>
* Since a {@code MonthDay} does not possess a year, the leap day of
* February 29th is considered valid.
* <p>
* This class implements {@link TemporalAccessor} rather than {@link Temporal}.
* This is because it is not possible to define whether February 29th is valid or not
* without external information, preventing the implementation of plus/minus.
* Related to this, {@code MonthDay} only provides access to query and set the fields
* {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH}.
* <p>
* The ISO-8601 calendar system is the modern civil calendar system used today
* in most of the world. It is equivalent to the proleptic Gregorian calendar
* system, in which today's rules for leap years are applied for all time.
* For most applications written today, the ISO-8601 rules are entirely suitable.
* However, any application that makes use of historical dates, and requires them
* to be accurate will find the ISO-8601 approach unsuitable.
*
* <p>
* This is a <a href="{@docRoot}/java/lang/doc-files/ValueBased.html">value-based</a>
* class; use of identity-sensitive operations (including reference equality
* ({@code ==}), identity hash code, or synchronization) on instances of
* {@code MonthDay} may have unpredictable results and should be avoided.
* The {@code equals} method should be used for comparisons.
*
* @implSpec
* This class is immutable and thread-safe.
*
* @since 1.8
*/
public final class
MonthDay
implements
TemporalAccessor,
TemporalAdjuster,
Comparable<
MonthDay>,
Serializable {
/**
* Serialization version.
*/
private static final long
serialVersionUID = -939150713474957432L;
/**
* Parser.
*/
private static final
DateTimeFormatter PARSER = new
DateTimeFormatterBuilder()
.
appendLiteral("--")
.
appendValue(
MONTH_OF_YEAR, 2)
.
appendLiteral('-')
.
appendValue(
DAY_OF_MONTH, 2)
.
toFormatter();
/**
* The month-of-year, not null.
*/
private final int
month;
/**
* The day-of-month.
*/
private final int
day;
//-----------------------------------------------------------------------
/**
* Obtains the current month-day from the system clock in the default time-zone.
* <p>
* This will query the {@link Clock#systemDefaultZone() system clock} in the default
* time-zone to obtain the current month-day.
* <p>
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @return the current month-day using the system clock and default time-zone, not null
*/
public static
MonthDay now() {
return
now(
Clock.
systemDefaultZone());
}
/**
* Obtains the current month-day from the system clock in the specified time-zone.
* <p>
* This will query the {@link Clock#system(ZoneId) system clock} to obtain the current month-day.
* Specifying the time-zone avoids dependence on the default time-zone.
* <p>
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @param zone the zone ID to use, not null
* @return the current month-day using the system clock, not null
*/
public static
MonthDay now(
ZoneId zone) {
return
now(
Clock.
system(
zone));
}
/**
* Obtains the current month-day from the specified clock.
* <p>
* This will query the specified clock to obtain the current month-day.
* Using this method allows the use of an alternate clock for testing.
* The alternate clock may be introduced using {@link Clock dependency injection}.
*
* @param clock the clock to use, not null
* @return the current month-day, not null
*/
public static
MonthDay now(
Clock clock) {
final
LocalDate now =
LocalDate.
now(
clock); // called once
return
MonthDay.
of(
now.
getMonth(),
now.
getDayOfMonth());
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code MonthDay}.
* <p>
* The day-of-month must be valid for the month within a leap year.
* Hence, for February, day 29 is valid.
* <p>
* For example, passing in April and day 31 will throw an exception, as
* there can never be April 31st in any year. By contrast, passing in
* February 29th is permitted, as that month-day can sometimes be valid.
*
* @param month the month-of-year to represent, not null
* @param dayOfMonth the day-of-month to represent, from 1 to 31
* @return the month-day, not null
* @throws DateTimeException if the value of any field is out of range,
* or if the day-of-month is invalid for the month
*/
public static
MonthDay of(
Month month, int
dayOfMonth) {
Objects.
requireNonNull(
month, "month");
DAY_OF_MONTH.
checkValidValue(
dayOfMonth);
if (
dayOfMonth >
month.
maxLength()) {
throw new
DateTimeException("Illegal value for DayOfMonth field, value " +
dayOfMonth +
" is not valid for month " +
month.
name());
}
return new
MonthDay(
month.
getValue(),
dayOfMonth);
}
/**
* Obtains an instance of {@code MonthDay}.
* <p>
* The day-of-month must be valid for the month within a leap year.
* Hence, for month 2 (February), day 29 is valid.
* <p>
* For example, passing in month 4 (April) and day 31 will throw an exception, as
* there can never be April 31st in any year. By contrast, passing in
* February 29th is permitted, as that month-day can sometimes be valid.
*
* @param month the month-of-year to represent, from 1 (January) to 12 (December)
* @param dayOfMonth the day-of-month to represent, from 1 to 31
* @return the month-day, not null
* @throws DateTimeException if the value of any field is out of range,
* or if the day-of-month is invalid for the month
*/
public static
MonthDay of(int
month, int
dayOfMonth) {
return
of(
Month.
of(
month),
dayOfMonth);
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code MonthDay} from a temporal object.
* <p>
* This obtains a month-day 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 MonthDay}.
* <p>
* The conversion extracts the {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} and
* {@link ChronoField#DAY_OF_MONTH DAY_OF_MONTH} fields.
* The extraction is only permitted if the temporal object has an ISO
* chronology, or can be converted to a {@code LocalDate}.
* <p>
* This method matches the signature of the functional interface {@link TemporalQuery}
* allowing it to be used as a query via method reference, {@code MonthDay::from}.
*
* @param temporal the temporal object to convert, not null
* @return the month-day, not null
* @throws DateTimeException if unable to convert to a {@code MonthDay}
*/
public static
MonthDay from(
TemporalAccessor temporal) {
if (
temporal instanceof
MonthDay) {
return (
MonthDay)
temporal;
}
try {
if (
IsoChronology.
INSTANCE.
equals(
Chronology.
from(
temporal)) == false) {
temporal =
LocalDate.
from(
temporal);
}
return
of(
temporal.
get(
MONTH_OF_YEAR),
temporal.
get(
DAY_OF_MONTH));
} catch (
DateTimeException ex) {
throw new
DateTimeException("Unable to obtain MonthDay from TemporalAccessor: " +
temporal + " of type " +
temporal.
getClass().
getName(),
ex);
}
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code MonthDay} from a text string such as {@code --12-03}.
* <p>
* The string must represent a valid month-day.
* The format is {@code --MM-dd}.
*
* @param text the text to parse such as "--12-03", not null
* @return the parsed month-day, not null
* @throws DateTimeParseException if the text cannot be parsed
*/
public static
MonthDay parse(
CharSequence text) {
return
parse(
text,
PARSER);
}
/**
* Obtains an instance of {@code MonthDay} from a text string using a specific formatter.
* <p>
* The text is parsed using the formatter, returning a month-day.
*
* @param text the text to parse, not null
* @param formatter the formatter to use, not null
* @return the parsed month-day, not null
* @throws DateTimeParseException if the text cannot be parsed
*/
public static
MonthDay parse(
CharSequence text,
DateTimeFormatter formatter) {
Objects.
requireNonNull(
formatter, "formatter");
return
formatter.
parse(
text,
MonthDay::from);
}
//-----------------------------------------------------------------------
/**
* Constructor, previously validated.
*
* @param month the month-of-year to represent, validated from 1 to 12
* @param dayOfMonth the day-of-month to represent, validated from 1 to 29-31
*/
private
MonthDay(int
month, int
dayOfMonth) {
this.
month =
month;
this.
day =
dayOfMonth;
}
//-----------------------------------------------------------------------
/**
* Checks if the specified field is supported.
* <p>
* This checks if this month-day 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 supported fields are:
* <ul>
* <li>{@code MONTH_OF_YEAR}
* <li>{@code YEAR}
* </ul>
* 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 month-day, false if not
*/
@
Override
public boolean
isSupported(
TemporalField field) {
if (
field instanceof
ChronoField) {
return
field ==
MONTH_OF_YEAR ||
field ==
DAY_OF_MONTH;
}
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 month-day 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
public
ValueRange range(
TemporalField field) {
if (
field ==
MONTH_OF_YEAR) {
return
field.
range();
} else if (
field ==
DAY_OF_MONTH) {
return
ValueRange.
of(1,
getMonth().
minLength(),
getMonth().
maxLength());
}
return
TemporalAccessor.super.range(
field);
}
/**
* Gets the value of the specified field from this month-day as an {@code int}.
* <p>
* This queries this month-day 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 {@link #isSupported(TemporalField) supported fields} will return valid
* values based on this month-day.
* 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
public int
get(
TemporalField field) {
return
range(
field).
checkValidIntValue(
getLong(
field),
field);
}
/**
* Gets the value of the specified field from this month-day as a {@code long}.
* <p>
* This queries this month-day 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 {@link #isSupported(TemporalField) supported fields} will return valid
* values based on this month-day.
* 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 instanceof
ChronoField) {
switch ((
ChronoField)
field) {
// alignedDOW and alignedWOM not supported because they cannot be set in with()
case
DAY_OF_MONTH: return
day;
case
MONTH_OF_YEAR: return
month;
}
throw new
UnsupportedTemporalTypeException("Unsupported field: " +
field);
}
return
field.
getFrom(this);
}
//-----------------------------------------------------------------------
/**
* Gets the month-of-year field from 1 to 12.
* <p>
* This method returns the month as an {@code int} from 1 to 12.
* Application code is frequently clearer if the enum {@link Month}
* is used by calling {@link #getMonth()}.
*
* @return the month-of-year, from 1 to 12
* @see #getMonth()
*/
public int
getMonthValue() {
return
month;
}
/**
* Gets the month-of-year field using the {@code Month} enum.
* <p>
* This method returns the enum {@link Month} for the month.
* This avoids confusion as to what {@code int} values mean.
* If you need access to the primitive {@code int} value then the enum
* provides the {@link Month#getValue() int value}.
*
* @return the month-of-year, not null
* @see #getMonthValue()
*/
public
Month getMonth() {
return
Month.
of(
month);
}
/**
* Gets the day-of-month field.
* <p>
* This method returns the primitive {@code int} value for the day-of-month.
*
* @return the day-of-month, from 1 to 31
*/
public int
getDayOfMonth() {
return
day;
}
//-----------------------------------------------------------------------
/**
* Checks if the year is valid for this month-day.
* <p>
* This method checks whether this month and day and the input year form
* a valid date. This can only return false for February 29th.
*
* @param year the year to validate
* @return true if the year is valid for this month-day
* @see Year#isValidMonthDay(MonthDay)
*/
public boolean
isValidYear(int
year) {
return (
day == 29 &&
month == 2 &&
Year.
isLeap(
year) == false) == false;
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this {@code MonthDay} with the month-of-year altered.
* <p>
* This returns a month-day with the specified month.
* If the day-of-month is invalid for the specified month, the day will
* be adjusted to the last valid day-of-month.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param month the month-of-year to set in the returned month-day, from 1 (January) to 12 (December)
* @return a {@code MonthDay} based on this month-day with the requested month, not null
* @throws DateTimeException if the month-of-year value is invalid
*/
public
MonthDay withMonth(int
month) {
return
with(
Month.
of(
month));
}
/**
* Returns a copy of this {@code MonthDay} with the month-of-year altered.
* <p>
* This returns a month-day with the specified month.
* If the day-of-month is invalid for the specified month, the day will
* be adjusted to the last valid day-of-month.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param month the month-of-year to set in the returned month-day, not null
* @return a {@code MonthDay} based on this month-day with the requested month, not null
*/
public
MonthDay with(
Month month) {
Objects.
requireNonNull(
month, "month");
if (
month.
getValue() == this.
month) {
return this;
}
int
day =
Math.
min(this.
day,
month.
maxLength());
return new
MonthDay(
month.
getValue(),
day);
}
/**
* Returns a copy of this {@code MonthDay} with the day-of-month altered.
* <p>
* This returns a month-day with the specified day-of-month.
* If the day-of-month is invalid for the month, an exception is thrown.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param dayOfMonth the day-of-month to set in the return month-day, from 1 to 31
* @return a {@code MonthDay} based on this month-day with the requested day, not null
* @throws DateTimeException if the day-of-month value is invalid,
* or if the day-of-month is invalid for the month
*/
public
MonthDay withDayOfMonth(int
dayOfMonth) {
if (
dayOfMonth == this.
day) {
return this;
}
return
of(
month,
dayOfMonth);
}
//-----------------------------------------------------------------------
/**
* Queries this month-day using the specified query.
* <p>
* This queries this month-day 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.
chronology()) {
return (R)
IsoChronology.
INSTANCE;
}
return
TemporalAccessor.super.query(
query);
}
/**
* Adjusts the specified temporal object to have this month-day.
* <p>
* This returns a temporal object of the same observable type as the input
* with the month and day-of-month changed to be the same as this.
* <p>
* The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
* twice, passing {@link ChronoField#MONTH_OF_YEAR} and
* {@link ChronoField#DAY_OF_MONTH} as the fields.
* If the specified temporal object does not use the ISO calendar system then
* a {@code DateTimeException} is thrown.
* <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 = thisMonthDay.adjustInto(temporal);
* temporal = temporal.with(thisMonthDay);
* </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) {
if (
Chronology.
from(
temporal).
equals(
IsoChronology.
INSTANCE) == false) {
throw new
DateTimeException("Adjustment only supported on ISO date-time");
}
temporal =
temporal.
with(
MONTH_OF_YEAR,
month);
return
temporal.
with(
DAY_OF_MONTH,
Math.
min(
temporal.
range(
DAY_OF_MONTH).
getMaximum(),
day));
}
/**
* Formats this month-day using the specified formatter.
* <p>
* This month-day will be passed to the formatter to produce a string.
*
* @param formatter the formatter to use, not null
* @return the formatted month-day string, not null
* @throws DateTimeException if an error occurs during printing
*/
public
String format(
DateTimeFormatter formatter) {
Objects.
requireNonNull(
formatter, "formatter");
return
formatter.
format(this);
}
//-----------------------------------------------------------------------
/**
* Combines this month-day with a year to create a {@code LocalDate}.
* <p>
* This returns a {@code LocalDate} formed from this month-day and the specified year.
* <p>
* A month-day of February 29th will be adjusted to February 28th in the resulting
* date if the year is not a leap year.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param year the year to use, from MIN_YEAR to MAX_YEAR
* @return the local date formed from this month-day and the specified year, not null
* @throws DateTimeException if the year is outside the valid range of years
*/
public
LocalDate atYear(int
year) {
return
LocalDate.
of(
year,
month,
isValidYear(
year) ?
day : 28);
}
//-----------------------------------------------------------------------
/**
* Compares this month-day to another month-day.
* <p>
* The comparison is based first on value of the month, then on the value of the day.
* It is "consistent with equals", as defined by {@link Comparable}.
*
* @param other the other month-day to compare to, not null
* @return the comparator value, negative if less, positive if greater
*/
@
Override
public int
compareTo(
MonthDay other) {
int
cmp = (
month -
other.
month);
if (
cmp == 0) {
cmp = (
day -
other.
day);
}
return
cmp;
}
/**
* Checks if this month-day is after the specified month-day.
*
* @param other the other month-day to compare to, not null
* @return true if this is after the specified month-day
*/
public boolean
isAfter(
MonthDay other) {
return
compareTo(
other) > 0;
}
/**
* Checks if this month-day is before the specified month-day.
*
* @param other the other month-day to compare to, not null
* @return true if this point is before the specified month-day
*/
public boolean
isBefore(
MonthDay other) {
return
compareTo(
other) < 0;
}
//-----------------------------------------------------------------------
/**
* Checks if this month-day is equal to another month-day.
* <p>
* The comparison is based on the time-line position of the month-day within a year.
*
* @param obj the object to check, null returns false
* @return true if this is equal to the other month-day
*/
@
Override
public boolean
equals(
Object obj) {
if (this ==
obj) {
return true;
}
if (
obj instanceof
MonthDay) {
MonthDay other = (
MonthDay)
obj;
return
month ==
other.
month &&
day ==
other.
day;
}
return false;
}
/**
* A hash code for this month-day.
*
* @return a suitable hash code
*/
@
Override
public int
hashCode() {
return (
month << 6) +
day;
}
//-----------------------------------------------------------------------
/**
* Outputs this month-day as a {@code String}, such as {@code --12-03}.
* <p>
* The output will be in the format {@code --MM-dd}:
*
* @return a string representation of this month-day, not null
*/
@
Override
public
String toString() {
return new
StringBuilder(10).
append("--")
.
append(
month < 10 ? "0" : "").
append(
month)
.
append(
day < 10 ? "-0" : "-").
append(
day)
.
toString();
}
//-----------------------------------------------------------------------
/**
* Writes the object using a
* <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
* @serialData
* <pre>
* out.writeByte(13); // identifies a MonthDay
* out.writeByte(month);
* out.writeByte(day);
* </pre>
*
* @return the instance of {@code Ser}, not null
*/
private
Object writeReplace() {
return new
Ser(
Ser.
MONTH_DAY_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");
}
void
writeExternal(
DataOutput out) throws
IOException {
out.
writeByte(
month);
out.
writeByte(
day);
}
static
MonthDay readExternal(
DataInput in) throws
IOException {
byte
month =
in.
readByte();
byte
day =
in.
readByte();
return
MonthDay.
of(
month,
day);
}
}