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With inspiration from other libraries
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
*******************************************************************************
* Copyright (C) 2008-2014, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.impl;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Date;
import java.util.TreeSet;
import com.ibm.icu.util.TimeZone;
/**
* JavaTimeZone inherits com.ibm.icu.util.TimeZone and wraps java.util.TimeZone.
* We used to have JDKTimeZone which wrapped Java TimeZone and used it as primary
* TimeZone implementation until ICU4J 3.4.1. This class works exactly like
* JDKTimeZone and allows ICU users who use ICU4J and JDK date/time/calendar
* services in mix to maintain only JDK timezone rules.
*
* This TimeZone subclass is returned by the TimeZone factory method getTimeZone(String)
* when the default timezone type in TimeZone class is TimeZone.TIMEZONE_JDK.
*/
public class JavaTimeZone extends TimeZone {
private static final long serialVersionUID = 6977448185543929364L;
private static final TreeSet AVAILABLESET;
private java.util.TimeZone javatz;
private transient java.util.Calendar javacal;
private static Method mObservesDaylightTime;
static {
AVAILABLESET = new TreeSet();
String[] availableIds = java.util.TimeZone.getAvailableIDs();
for (int i = 0; i < availableIds.length; i++) {
AVAILABLESET.add(availableIds[i]);
}
try {
mObservesDaylightTime = java.util.TimeZone.class.getMethod("observesDaylightTime", (Class[]) null);
} catch (NoSuchMethodException e) {
// Java 6 or older
} catch (SecurityException e) {
// not visible
}
}
/**
* Constructs a JavaTimeZone with the default Java TimeZone
*/
public JavaTimeZone() {
this(java.util.TimeZone.getDefault(), null);
}
/**
* Constructs a JavaTimeZone with the specified Java TimeZone and ID.
* @param jtz the Java TimeZone
* @param id the ID of the zone. if null, the zone ID is initialized
* by the given Java TimeZone's ID.
*/
public JavaTimeZone(java.util.TimeZone jtz, String id) {
if (id == null) {
id = jtz.getID();
}
javatz = jtz;
setID(id);
javacal = new java.util.GregorianCalendar(javatz);
}
/**
* Creates an instance of JavaTimeZone with the given timezone ID.
* @param id A timezone ID, either a system ID or a custom ID.
* @return An instance of JavaTimeZone for the given ID, or null
* when the ID cannot be understood.
*/
public static JavaTimeZone createTimeZone(String id) {
java.util.TimeZone jtz = null;
if (AVAILABLESET.contains(id)) {
jtz = java.util.TimeZone.getTimeZone(id);
}
if (jtz == null) {
// Use ICU's canonical ID mapping
boolean[] isSystemID = new boolean[1];
String canonicalID = TimeZone.getCanonicalID(id, isSystemID);
if (isSystemID[0] && AVAILABLESET.contains(canonicalID)) {
jtz = java.util.TimeZone.getTimeZone(canonicalID);
}
}
if (jtz == null) {
return null;
}
return new JavaTimeZone(jtz, id);
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#getOffset(int, int, int, int, int, int)
*/
@Override
public int getOffset(int era, int year, int month, int day, int dayOfWeek, int milliseconds) {
return javatz.getOffset(era, year, month, day, dayOfWeek, milliseconds);
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#getOffset(long, boolean, int[])
*/
@Override
public void getOffset(long date, boolean local, int[] offsets) {
synchronized (javacal) {
if (local) {
int fields[] = new int[6];
Grego.timeToFields(date, fields);
int hour, min, sec, mil;
int tmp = fields[5];
mil = tmp % 1000;
tmp /= 1000;
sec = tmp % 60;
tmp /= 60;
min = tmp % 60;
hour = tmp / 60;
javacal.clear();
javacal.set(fields[0], fields[1], fields[2], hour, min, sec);
javacal.set(java.util.Calendar.MILLISECOND, mil);
int doy1, hour1, min1, sec1, mil1;
doy1 = javacal.get(java.util.Calendar.DAY_OF_YEAR);
hour1 = javacal.get(java.util.Calendar.HOUR_OF_DAY);
min1 = javacal.get(java.util.Calendar.MINUTE);
sec1 = javacal.get(java.util.Calendar.SECOND);
mil1 = javacal.get(java.util.Calendar.MILLISECOND);
if (fields[4] != doy1 || hour != hour1 || min != min1 || sec != sec1 || mil != mil1) {
// Calendar field(s) were changed due to the adjustment for non-existing time
// Note: This code does not support non-existing local time at year boundary properly.
// But, it should work fine for real timezones.
int dayDelta = Math.abs(doy1 - fields[4]) > 1 ? 1 : doy1 - fields[4];
int delta = ((((dayDelta * 24) + hour1 - hour) * 60 + min1 - min) * 60 + sec1 - sec) * 1000 + mil1 - mil;
// In this case, we use the offsets before the transition
javacal.setTimeInMillis(javacal.getTimeInMillis() - delta - 1);
}
} else {
javacal.setTimeInMillis(date);
}
offsets[0] = javacal.get(java.util.Calendar.ZONE_OFFSET);
offsets[1] = javacal.get(java.util.Calendar.DST_OFFSET);
}
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#getRawOffset()
*/
@Override
public int getRawOffset() {
return javatz.getRawOffset();
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#inDaylightTime(java.util.Date)
*/
@Override
public boolean inDaylightTime(Date date) {
return javatz.inDaylightTime(date);
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#setRawOffset(int)
*/
@Override
public void setRawOffset(int offsetMillis) {
if (isFrozen()) {
throw new UnsupportedOperationException("Attempt to modify a frozen JavaTimeZone instance.");
}
javatz.setRawOffset(offsetMillis);
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#useDaylightTime()
*/
@Override
public boolean useDaylightTime() {
return javatz.useDaylightTime();
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#observesDaylightTime()
*/
@Override
public boolean observesDaylightTime() {
if (mObservesDaylightTime != null) {
// Java 7+
try {
return (Boolean)mObservesDaylightTime.invoke(javatz, (Object[]) null);
} catch (IllegalAccessException e) {
} catch (IllegalArgumentException e) {
} catch (InvocationTargetException e) {
}
}
return super.observesDaylightTime();
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#getDSTSavings()
*/
@Override
public int getDSTSavings() {
return javatz.getDSTSavings();
}
public java.util.TimeZone unwrap() {
return javatz;
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#clone()
*/
@Override
public Object clone() {
if (isFrozen()) {
return this;
}
return cloneAsThawed();
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#hashCode()
*/
@Override
public int hashCode() {
return super.hashCode() + javatz.hashCode();
}
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
s.defaultReadObject();
javacal = new java.util.GregorianCalendar(javatz);
}
// Freezable stuffs
private transient volatile boolean isFrozen = false;
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#isFrozen()
*/
@Override
public boolean isFrozen() {
return isFrozen;
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#freeze()
*/
@Override
public TimeZone freeze() {
isFrozen = true;
return this;
}
/* (non-Javadoc)
* @see com.ibm.icu.util.TimeZone#cloneAsThawed()
*/
@Override
public TimeZone cloneAsThawed() {
JavaTimeZone tz = (JavaTimeZone)super.cloneAsThawed();
tz.javatz = (java.util.TimeZone)javatz.clone();
tz.javacal = new java.util.GregorianCalendar(javatz); // easier than synchronized javacal.clone()
tz.isFrozen = false;
return tz;
}
}