TimeZoneRule.java
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2007-2016, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.util;
import java.io.Serializable;
import java.util.Date;
/**
* <code>TimeZoneRule</code> is an abstract class representing a rule for time zone. <code>
* TimeZoneRule</code> has a set of time zone attributes, such as zone name, raw offset (UTC offset
* for standard time) and daylight saving time offset.
*
* @see com.ibm.icu.util.TimeZoneTransition
* @see com.ibm.icu.util.RuleBasedTimeZone
* @stable ICU 3.8
*/
public abstract class TimeZoneRule implements Serializable {
private static final long serialVersionUID = 6374143828553768100L;
private final String name;
private final int rawOffset;
private final int dstSavings;
/**
* Constructs a <code>TimeZoneRule</code> with the name, the GMT offset of its standard time and
* the amount of daylight saving offset adjustment.
*
* @param name The time zone name.
* @param rawOffset The UTC offset of its standard time in milliseconds.
* @param dstSavings The amount of daylight saving offset adjustment in milliseconds. If this is
* a rule for standard time, the value of this argument is 0.
* @stable ICU 3.8
*/
public TimeZoneRule(String name, int rawOffset, int dstSavings) {
this.name = name;
this.rawOffset = rawOffset;
this.dstSavings = dstSavings;
}
/**
* Gets the name of this time zone.
*
* @return The name of this time zone.
* @stable ICU 3.8
*/
public String getName() {
return name;
}
/**
* Gets the standard time offset.
*
* @return The standard time offset from UTC in milliseconds.
* @stable ICU 3.8
*/
public int getRawOffset() {
return rawOffset;
}
/**
* Gets the amount of daylight saving delta time from the standard time.
*
* @return The amount of daylight saving offset used by this rule in milliseconds.
* @stable ICU 3.8
*/
public int getDSTSavings() {
return dstSavings;
}
/**
* Returns if this rule represents the same rule and offsets as another. When two <code>
* TimeZoneRule</code> objects differ only its names, this method returns true.
*
* @param other The <code>TimeZoneRule</code> object to be compared with.
* @return true if the other <code>TimeZoneRule</code> is the same as this one.
* @stable ICU 3.8
*/
public boolean isEquivalentTo(TimeZoneRule other) {
if (rawOffset == other.rawOffset && dstSavings == other.dstSavings) {
return true;
}
return false;
}
/**
* Gets the very first time when this rule takes effect.
*
* @param prevRawOffset The standard time offset from UTC before this rule takes effect in
* milliseconds.
* @param prevDSTSavings The amount of daylight saving offset from the standard time.
* @return The very first time when this rule takes effect.
* @stable ICU 3.8
*/
public abstract Date getFirstStart(int prevRawOffset, int prevDSTSavings);
/**
* Gets the final time when this rule takes effect.
*
* @param prevRawOffset The standard time offset from UTC before this rule takes effect in
* milliseconds.
* @param prevDSTSavings The amount of daylight saving offset from the standard time.
* @return The very last time when this rule takes effect, or null if this rule is applied for
* future dates infinitely.
* @stable ICU 3.8
*/
public abstract Date getFinalStart(int prevRawOffset, int prevDSTSavings);
/**
* Gets the first time when this rule takes effect after the specified time.
*
* @param base The first time after this time is returned.
* @param prevRawOffset The standard time offset from UTC before this rule takes effect in
* milliseconds.
* @param prevDSTSavings The amount of daylight saving offset from the standard time.
* @param inclusive Whether the base time is inclusive or not.
* @return The first time when this rule takes effect after the specified time, or null when
* this rule never takes effect after the specified time.
* @stable ICU 3.8
*/
public abstract Date getNextStart(
long base, int prevRawOffset, int prevDSTSavings, boolean inclusive);
/**
* Gets the most recent time when this rule takes effect before the specified time.
*
* @param base The most recent time when this rule takes effect before this time is returned.
* @param prevRawOffset The standard time offset from UTC before this rule takes effect in
* milliseconds.
* @param prevDSTSavings The amount of daylight saving offset from the standard time.
* @param inclusive Whether the base time is inclusive or not.
* @return The most recent time when this rule takes effect before the specified time, or null
* when this rule never takes effect before the specified time.
* @stable ICU 3.8
*/
public abstract Date getPreviousStart(
long base, int prevRawOffset, int prevDSTSavings, boolean inclusive);
/**
* Returns if this <code>TimeZoneRule</code> has one or more start times.
*
* @return true if this <code>TimeZoneRule</code> has one or more start times.
* @stable ICU 3.8
*/
public abstract boolean isTransitionRule();
/**
* Returns a <code>String</code> representation of this <code>TimeZoneRule</code> object. This
* method is used for debugging purpose only. The string representation can be changed in future
* version of ICU without any notice.
*
* @stable ICU 3.8
*/
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append("name=" + name);
buf.append(", stdOffset=" + rawOffset);
buf.append(", dstSaving=" + dstSavings);
return buf.toString();
}
}