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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
*******************************************************************************
* Copyright (C) 2011, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.samples.util.timezone;
import java.util.Date;
import com.ibm.icu.text.SimpleDateFormat;
import com.ibm.icu.util.BasicTimeZone;
import com.ibm.icu.util.Calendar;
import com.ibm.icu.util.GregorianCalendar;
import com.ibm.icu.util.TimeZone;
import com.ibm.icu.util.TimeZoneRule;
import com.ibm.icu.util.TimeZoneTransition;
import com.ibm.icu.util.ULocale;
/**
* com.ibm.icu.util.BasicTimeZone Coding Examples
*/
public class BasicTimeZoneExample {
public static void main(String... args) {
nextTransitionExample();
previousTransitionExample();
timeZoneRulesExample();
equivalentTransitionsExample();
}
public static void nextTransitionExample() {
// ---getNextTransitionExample
System.out.println("### Iterates time zone transitions in America/Los_Angeles starting 2005-01-01 and forward");
// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone("America/Los_Angeles", TimeZone.TIMEZONE_ICU);
// Date format for the wall time
SimpleDateFormat wallTimeFmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", ULocale.US);
wallTimeFmt.setTimeZone(btz);
long start = 1104537600000L; // 2005-01-01 0:00 UTC
for (int i = 0; i < 5; i++) { // Up to 5 transitions
TimeZoneTransition trans = btz.getNextTransition(start, false /* not including start time */);
// Display the transition time and offset information
long transTime = trans.getTime();
System.out.println(wallTimeFmt.format(new Date(transTime - 1)) + " -> " + wallTimeFmt.format(new Date(transTime)));
System.out.println(" - Before (Offset/Save): " + trans.getFrom().getRawOffset() + "/" + trans.getFrom().getDSTSavings());
System.out.println(" - After (Offset/Save): " + trans.getTo().getRawOffset() + "/" + trans.getTo().getDSTSavings());
// Update start time for next transition
start = transTime;
}
// ---getNextTransitionExample
}
public static void previousTransitionExample() {
// ---getPreviousTransitionExample
System.out.println("### Iterates time zone transitions in America/Los_Angeles starting 2010-01-01 and backward");
// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone("America/Los_Angeles", TimeZone.TIMEZONE_ICU);
// Date format for the wall time
SimpleDateFormat wallTimeFmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z", ULocale.US);
wallTimeFmt.setTimeZone(btz);
long start = 1262304000000L; // 2010-01-01 0:00 UTC
for (int i = 0; i < 5; i++) { // Up to 5 transitions
TimeZoneTransition trans = btz.getPreviousTransition(start, false /* not including start time */);
// Display the transition time and offset information
long transTime = trans.getTime();
System.out.println(wallTimeFmt.format(new Date(transTime - 1)) + " -> " + wallTimeFmt.format(new Date(transTime)));
System.out.println(" - Before (Offset/Save): " + trans.getFrom().getRawOffset() + "/" + trans.getFrom().getDSTSavings());
System.out.println(" - After (Offset/Save): " + trans.getTo().getRawOffset() + "/" + trans.getTo().getDSTSavings());
// Update start time for next transition
start = transTime;
}
// ---getPreviousTransitionExample
}
public static void timeZoneRulesExample() {
// ---getTimeZoneRulesExample
System.out.println("### Extracts time zone rules used by America/Los_Angeles since year 2005");
// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone("America/Los_Angeles", TimeZone.TIMEZONE_ICU);
long since = 1104537600000L; // 2005-01-01 0:00 UTC
TimeZoneRule[] rules = btz.getTimeZoneRules(since);
System.out.println("Rule(initial): " + rules[0]);
for (int i = 1; i < rules.length; i++) {
System.out.println("Rule: " + rules[i]);
}
// ---getTimeZoneRulesExample
}
public static void equivalentTransitionsExample() {
// ---hasEquivalentTransitionsExample
System.out.println("### Compare America/New_York and America/Detroit since year 1970");
// A TimeZone instance created by getTimeZone with TIMEZONE_ICU is always a BasicTimeZone
BasicTimeZone tzNewYork = (BasicTimeZone)TimeZone.getTimeZone("America/New_York", TimeZone.TIMEZONE_ICU);
BasicTimeZone tzDetroit = (BasicTimeZone)TimeZone.getTimeZone("America/Detroit", TimeZone.TIMEZONE_ICU);
GregorianCalendar cal = new GregorianCalendar(TimeZone.getTimeZone("Etc/GMT"));
// Compare these time zones every 10 years since year 1970 up to year 2009
for (int startYear = 1970; startYear <= 2000; startYear += 10) {
long start, end;
cal.set(startYear, Calendar.JANUARY, 1, 0, 0, 0);
cal.set(Calendar.MILLISECOND, 0);
start = cal.getTimeInMillis();
// Set the end time to the end of startYear + 9
int endYear = startYear + 9;
cal.set(endYear + 1, Calendar.JANUARY, 1, 0, 0, 0);
end = cal.getTimeInMillis() - 1;
// Check if these two zones have equivalent time zone transitions for the given time range
boolean isEquivalent = tzNewYork.hasEquivalentTransitions(tzDetroit, start, end);
System.out.println(startYear + "-" + endYear + ": " + isEquivalent);
}
// ---hasEquivalentTransitionsExample
}
}
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