org.bardframework.time.zone.ZoneOffsetTransitionRule Maven / Gradle / Ivy
package org.bardframework.time.zone;
import lombok.Getter;
import org.bardframework.time.LocalDateJalali;
import org.bardframework.time.LocalDateTimeJalali;
import org.bardframework.time.MonthJalali;
import java.io.*;
import java.time.DayOfWeek;
import java.time.LocalTime;
import java.time.ZoneOffset;
import java.time.chrono.IsoChronology;
import java.util.Objects;
import static java.time.temporal.TemporalAdjusters.nextOrSame;
import static java.time.temporal.TemporalAdjusters.previousOrSame;
/**
* A rule expressing how to create a transition.
*
* This class allows rules for identifying future transitions to be expressed.
* A rule might be written in many forms:
*
* - the 16th March
*
- the Sunday on or after the 16th March
*
- the Sunday on or before the 16th March
*
- the last Sunday in February
*
* These different rule types can be expressed and queried.
*
* this class is immutable and thread-safe.
*/
@Getter
public final class ZoneOffsetTransitionRule implements Serializable {
/**
* Serialization version.
*/
private static final long serialVersionUID = 6889046316657758795L;
/**
* The month of the month-day of the first day of the cutover week.
* The actual date will be adjusted by the dowChange field.
*/
private final MonthJalali month;
/**
* The day-of-month of the month-day of the cutover week.
* If positive, it is the start of the week where the cutover can occur.
* If negative, it represents the end of the week where cutover can occur.
* The value is the number of days from the end of the month, such that
* {@code -1} is the last day of the month, {@code -2} is the second
* to last day, and so on.
*/
private final byte dom;
/**
* The cutover day-of-week, null to retain the day-of-month.
*/
private final DayOfWeek dow;
/**
* The cutover time in the 'before' offset.
*/
private final LocalTime time;
/**
* Whether the cutover time is midnight at the end of day.
*/
private final boolean timeEndOfDay;
/**
* The definition of how the local time should be interpreted.
*/
private final TimeDefinition timeDefinition;
/**
* The standard offset at the cutover.
*/
private final ZoneOffset standardOffset;
/**
* The offset before the cutover.
*/
private final ZoneOffset offsetBefore;
/**
* The offset after the cutover.
*/
private final ZoneOffset offsetAfter;
/**
* Creates an instance defining the yearly rule to create transitions between two offsets.
*
* @param month the month of the month-day of the first day of the cutover week, not null
* @param dayOfMonthIndicator the day of the month-day of the cutover week, positive if the week is that
* day or later, negative if the week is that day or earlier, counting from the last day of the month,
* from -28 to 31 excluding 0
* @param dayOfWeek the required day-of-week, null if the month-day should not be changed
* @param time the cutover time in the 'before' offset, not null
* @param timeEndOfDay whether the time is midnight at the end of day
* @param timeDefinition how to interpret the cutover
* @param standardOffset the standard offset in force at the cutover, not null
* @param offsetBefore the offset before the cutover, not null
* @param offsetAfter the offset after the cutover, not null
* @throws IllegalArgumentException if the day of month indicator is invalid
* @throws IllegalArgumentException if the end of day flag is true when the time is not midnight
*/
ZoneOffsetTransitionRule(
MonthJalali month,
int dayOfMonthIndicator,
DayOfWeek dayOfWeek,
LocalTime time,
boolean timeEndOfDay,
TimeDefinition timeDefinition,
ZoneOffset standardOffset,
ZoneOffset offsetBefore,
ZoneOffset offsetAfter) {
assert time.getNano() == 0;
this.month = month;
this.dom = (byte) dayOfMonthIndicator;
this.dow = dayOfWeek;
this.time = time;
this.timeEndOfDay = timeEndOfDay;
this.timeDefinition = timeDefinition;
this.standardOffset = standardOffset;
this.offsetBefore = offsetBefore;
this.offsetAfter = offsetAfter;
}
/**
* Obtains an instance defining the yearly rule to create transitions between two offsets.
*
* Applications should normally obtain an instance from {@link ZoneRules}.
* This factory is only intended for use when creating {@link ZoneRules}.
*
* @param month the month of the month-day of the first day of the cutover week, not null
* @param dayOfMonthIndicator the day of the month-day of the cutover week, positive if the week is that
* day or later, negative if the week is that day or earlier, counting from the last day of the month,
* from -28 to 31 excluding 0
* @param dayOfWeek the required day-of-week, null if the month-day should not be changed
* @param time the cutover time in the 'before' offset, not null
* @param timeEndOfDay whether the time is midnight at the end of day
* @param timeDefinition how to interpret the cutover
* @param standardOffset the standard offset in force at the cutover, not null
* @param offsetBefore the offset before the cutover, not null
* @param offsetAfter the offset after the cutover, not null
* @return the rule, not null
* @throws IllegalArgumentException if the day of month indicator is invalid
* @throws IllegalArgumentException if the end of day flag is true when the time is not midnight
* @throws IllegalArgumentException if {@code time.getNano()} returns non-zero value
*/
public static ZoneOffsetTransitionRule of(
MonthJalali month,
int dayOfMonthIndicator,
DayOfWeek dayOfWeek,
LocalTime time,
boolean timeEndOfDay,
TimeDefinition timeDefinition,
ZoneOffset standardOffset,
ZoneOffset offsetBefore,
ZoneOffset offsetAfter) {
Objects.requireNonNull(month, "month");
Objects.requireNonNull(time, "time");
Objects.requireNonNull(timeDefinition, "timeDefinition");
Objects.requireNonNull(standardOffset, "standardOffset");
Objects.requireNonNull(offsetBefore, "offsetBefore");
Objects.requireNonNull(offsetAfter, "offsetAfter");
if (dayOfMonthIndicator < -28 || dayOfMonthIndicator > 31 || dayOfMonthIndicator == 0) {
throw new IllegalArgumentException("Day of month indicator must be between -28 and 31 inclusive excluding zero");
}
if (timeEndOfDay && !time.equals(LocalTime.MIDNIGHT)) {
throw new IllegalArgumentException("Time must be midnight when end of day flag is true");
}
if (time.getNano() != 0) {
throw new IllegalArgumentException("Time's nano-of-second must be zero");
}
return new ZoneOffsetTransitionRule(month, dayOfMonthIndicator, dayOfWeek, time, timeEndOfDay, timeDefinition, standardOffset, offsetBefore, offsetAfter);
}
//-----------------------------------------------------------------------
/**
* Reads the state from the stream.
*
* @param in the input stream, not null
* @return the created object, not null
* @throws IOException if an error occurs
*/
static ZoneOffsetTransitionRule readExternal(DataInput in) throws IOException {
int data = in.readInt();
MonthJalali month = MonthJalali.of(data >>> 28);
int dom = ((data & (63 << 22)) >>> 22) - 32;
int dowByte = (data & (7 << 19)) >>> 19;
DayOfWeek dow = dowByte == 0 ? null : DayOfWeek.of(dowByte);
int timeByte = (data & (31 << 14)) >>> 14;
TimeDefinition defn = TimeDefinition.values()[(data & (3 << 12)) >>> 12];
int stdByte = (data & (255 << 4)) >>> 4;
int beforeByte = (data & (3 << 2)) >>> 2;
int afterByte = (data & 3);
LocalTime time = (timeByte == 31 ? LocalTime.ofSecondOfDay(in.readInt()) : LocalTime.of(timeByte % 24, 0));
ZoneOffset std = (stdByte == 255 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds((stdByte - 128) * 900));
ZoneOffset before = (beforeByte == 3 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(std.getTotalSeconds() + beforeByte * 1800));
ZoneOffset after = (afterByte == 3 ? ZoneOffset.ofTotalSeconds(in.readInt()) : ZoneOffset.ofTotalSeconds(std.getTotalSeconds() + afterByte * 1800));
return ZoneOffsetTransitionRule.of(month, dom, dow, time, timeByte == 24, defn, std, before, after);
}
/**
* Defend against malicious streams.
*
* @param s the stream to read
* @throws InvalidObjectException always
*/
private void readObject(ObjectInputStream s) throws InvalidObjectException {
throw new InvalidObjectException("Deserialization via serialization delegate");
}
/**
* Writes the object using a
* dedicated serialized form.
*
* @return the replacing object, not null
* @serialData Refer to the serialized form of
* ZoneRules.writeReplace
* for the encoding of epoch seconds and offsets.
*
{@code
*
* out.writeByte(3); // identifies a ZoneOffsetTransitionRule
* final int timeSecs = (timeEndOfDay ? 86400 : time.toSecondOfDay());
* final int stdOffset = standardOffset.getTotalSeconds();
* final int beforeDiff = offsetBefore.getTotalSeconds() - stdOffset;
* final int afterDiff = offsetAfter.getTotalSeconds() - stdOffset;
* final int timeByte = (timeSecs % 3600 == 0 ? (timeEndOfDay ? 24 : time.getHour()) : 31);
* final int stdOffsetByte = (stdOffset % 900 == 0 ? stdOffset / 900 + 128 : 255);
* final int beforeByte = (beforeDiff == 0 || beforeDiff == 1800 || beforeDiff == 3600 ? beforeDiff / 1800 : 3);
* final int afterByte = (afterDiff == 0 || afterDiff == 1800 || afterDiff == 3600 ? afterDiff / 1800 : 3);
* final int dowByte = (dow == null ? 0 : dow.getValue());
* int b = (month.getValue() << 28) + // 4 bits
* ((dom + 32) << 22) + // 6 bits
* (dowByte << 19) + // 3 bits
* (timeByte << 14) + // 5 bits
* (timeDefinition.ordinal() << 12) + // 2 bits
* (stdOffsetByte << 4) + // 8 bits
* (beforeByte << 2) + // 2 bits
* afterByte; // 2 bits
* out.writeInt(b);
* if (timeByte == 31) {
* out.writeInt(timeSecs);
* }
* if (stdOffsetByte == 255) {
* out.writeInt(stdOffset);
* }
* if (beforeByte == 3) {
* out.writeInt(offsetBefore.getTotalSeconds());
* }
* if (afterByte == 3) {
* out.writeInt(offsetAfter.getTotalSeconds());
* }
* }
*
*/
private Object writeReplace() {
return new Ser(Ser.ZOTRULE, this);
}
/**
* Writes the state to the stream.
*
* @param out the output stream, not null
* @throws IOException if an error occurs
*/
void writeExternal(DataOutput out) throws IOException {
final int timeSecs = (timeEndOfDay ? 86400 : time.toSecondOfDay());
final int stdOffset = standardOffset.getTotalSeconds();
final int beforeDiff = offsetBefore.getTotalSeconds() - stdOffset;
final int afterDiff = offsetAfter.getTotalSeconds() - stdOffset;
final int timeByte = (timeSecs % 3600 == 0 ? (timeEndOfDay ? 24 : time.getHour()) : 31);
final int stdOffsetByte = (stdOffset % 900 == 0 ? stdOffset / 900 + 128 : 255);
final int beforeByte = (beforeDiff == 0 || beforeDiff == 1800 || beforeDiff == 3600 ? beforeDiff / 1800 : 3);
final int afterByte = (afterDiff == 0 || afterDiff == 1800 || afterDiff == 3600 ? afterDiff / 1800 : 3);
final int dowByte = (dow == null ? 0 : dow.getValue());
int b = (month.getValue() << 28) + // 4 bits
((dom + 32) << 22) + // 6 bits
(dowByte << 19) + // 3 bits
(timeByte << 14) + // 5 bits
(timeDefinition.ordinal() << 12) + // 2 bits
(stdOffsetByte << 4) + // 8 bits
(beforeByte << 2) + // 2 bits
afterByte; // 2 bits
out.writeInt(b);
if (timeByte == 31) {
out.writeInt(timeSecs);
}
if (stdOffsetByte == 255) {
out.writeInt(stdOffset);
}
if (beforeByte == 3) {
out.writeInt(offsetBefore.getTotalSeconds());
}
if (afterByte == 3) {
out.writeInt(offsetAfter.getTotalSeconds());
}
}
//-----------------------------------------------------------------------
/**
* Gets the indicator of the day-of-month of the transition.
*
* If the rule defines an exact date then the day is the month of that date.
*
* If the rule defines a week where the transition might occur, then the day
* defines either the start of the end of the transition week.
*
* If the value is positive, then it represents a normal day-of-month, and is the
* earliest possible date that the transition can be.
* The date may refer to 29th February which should be treated as 1st March in non-leap years.
*
* If the value is negative, then it represents the number of days back from the
* end of the month where {@code -1} is the last day of the month.
* In this case, the day identified is the latest possible date that the transition can be.
*
* @return the day-of-month indicator, from -28 to 31 excluding 0
*/
public int getDayOfMonthIndicator() {
return dom;
}
/**
* Gets the day-of-week of the transition.
*
* If the rule defines an exact date then this returns null.
*
* If the rule defines a week where the cutover might occur, then this method
* returns the day-of-week that the month-day will be adjusted to.
* If the day is positive then the adjustment is later.
* If the day is negative then the adjustment is earlier.
*
* @return the day-of-week that the transition occurs, null if the rule defines an exact date
*/
public DayOfWeek getDayOfWeek() {
return dow;
}
/**
* Gets the local time of day of the transition which must be checked with
* {@link #isMidnightEndOfDay()}.
*
* The time is converted into an instant using the time definition.
*
* @return the local time of day of the transition, not null
*/
public LocalTime getLocalTime() {
return time;
}
/**
* Is the transition local time midnight at the end of day.
*
* The transition may be represented as occurring at 24:00.
*
* @return whether a local time of midnight is at the start or end of the day
*/
public boolean isMidnightEndOfDay() {
return timeEndOfDay;
}
//-----------------------------------------------------------------------
/**
* Creates a transition instance for the specified year.
*
* Calculations are performed using the ISO-8601 chronology.
*
* @param year the year to create a transition for, not null
* @return the transition instance, not null
*/
public ZoneOffsetTransition createTransition(int year) {
LocalDateJalali date;
if (dom < 0) {
date = LocalDateJalali.of(year, month, month.length(IsoChronology.INSTANCE.isLeapYear(year)) + 1 + dom);
if (dow != null) {
date = date.with(previousOrSame(dow));
}
} else {
date = LocalDateJalali.of(year, month, dom);
if (dow != null) {
date = date.with(nextOrSame(dow));
}
}
if (timeEndOfDay) {
date = date.plusDays(1);
}
LocalDateTimeJalali localDT = LocalDateTimeJalali.of(date, time);
LocalDateTimeJalali transition = timeDefinition.createDateTime(localDT, standardOffset, offsetBefore);
return new ZoneOffsetTransition(transition, offsetBefore, offsetAfter);
}
//-----------------------------------------------------------------------
/**
* Checks if this object equals another.
*
* The entire state of the object is compared.
*
* @param otherRule the other object to compare to, null returns false
* @return true if equal
*/
@Override
public boolean equals(Object otherRule) {
if (otherRule == this) {
return true;
}
if (otherRule instanceof ZoneOffsetTransitionRule) {
ZoneOffsetTransitionRule other = (ZoneOffsetTransitionRule) otherRule;
return month == other.month && dom == other.dom && dow == other.dow &&
timeDefinition == other.timeDefinition &&
time.equals(other.time) &&
timeEndOfDay == other.timeEndOfDay &&
standardOffset.equals(other.standardOffset) &&
offsetBefore.equals(other.offsetBefore) &&
offsetAfter.equals(other.offsetAfter);
}
return false;
}
/**
* Returns a suitable hash code.
*
* @return the hash code
*/
@Override
public int hashCode() {
int hash = ((time.toSecondOfDay() + (timeEndOfDay ? 1 : 0)) << 15) +
(month.ordinal() << 11) + ((dom + 32) << 5) +
((dow == null ? 7 : dow.ordinal()) << 2) + (timeDefinition.ordinal());
return hash ^ standardOffset.hashCode() ^
offsetBefore.hashCode() ^ offsetAfter.hashCode();
}
//-----------------------------------------------------------------------
/**
* Returns a string describing this object.
*
* @return a string for debugging, not null
*/
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append("TransitionRule[")
.append(offsetBefore.compareTo(offsetAfter) > 0 ? "Gap " : "Overlap ")
.append(offsetBefore).append(" to ").append(offsetAfter).append(", ");
if (dow != null) {
if (dom == -1) {
buf.append(dow.name()).append(" on or before last day of ").append(month.name());
} else if (dom < 0) {
buf.append(dow.name()).append(" on or before last day minus ").append(-dom - 1).append(" of ").append(month.name());
} else {
buf.append(dow.name()).append(" on or after ").append(month.name()).append(' ').append(dom);
}
} else {
buf.append(month.name()).append(' ').append(dom);
}
buf.append(" at ").append(timeEndOfDay ? "24:00" : time.toString())
.append(" ").append(timeDefinition)
.append(", standard offset ").append(standardOffset)
.append(']');
return buf.toString();
}
//-----------------------------------------------------------------------
/**
* A definition of the way a local time can be converted to the actual
* transition date-time.
*
* Time zone rules are expressed in one of three ways:
*
* - Relative to UTC
* - Relative to the standard offset in force
* - Relative to the wall offset (what you would see on a clock on the wall)
*
*/
public enum TimeDefinition {
/**
* The local date-time is expressed in terms of the UTC offset.
*/
UTC,
/**
* The local date-time is expressed in terms of the wall offset.
*/
WALL,
/**
* The local date-time is expressed in terms of the standard offset.
*/
STANDARD;
/**
* Converts the specified local date-time to the local date-time actually
* seen on a wall clock.
*
* This method converts using the type of this enum.
* The output is defined relative to the 'before' offset of the transition.
*
* The UTC type uses the UTC offset.
* The STANDARD type uses the standard offset.
* The WALL type returns the input date-time.
* The result is intended for use with the wall-offset.
*
* @param dateTime the local date-time, not null
* @param standardOffset the standard offset, not null
* @param wallOffset the wall offset, not null
* @return the date-time relative to the wall/before offset, not null
*/
public LocalDateTimeJalali createDateTime(LocalDateTimeJalali dateTime, ZoneOffset standardOffset, ZoneOffset wallOffset) {
switch (this) {
case UTC: {
int difference = wallOffset.getTotalSeconds() - ZoneOffset.UTC.getTotalSeconds();
return dateTime.plusSeconds(difference);
}
case STANDARD: {
int difference = wallOffset.getTotalSeconds() - standardOffset.getTotalSeconds();
return dateTime.plusSeconds(difference);
}
default: // WALL
return dateTime;
}
}
}
}