本章介绍TimeZone。
1. TimeZone 简介
TimeZone 表示时区偏移量，也可以计算夏令时。
在操作 Date, Calendar等表示日期/时间的对象时，经常会用到TimeZone；因为不同的时区，时间不同。
下面说说TimeZone对象的 2种常用创建方式。
(01) 获取默认的TimeZone对象
使用方法：
TimeZone tz = TimeZone.getDefault()
(02) 使用 getTimeZone(String id) 方法获取TimeZone对象
使用方法：
// 获取 “GMT+08:00”对应的时区
TimeZone china = TimeZone.getTimeZone("GMT+:08:00");
// 获取 “中国/重庆”对应的时区
TimeZone chongqing = TimeZone.getTimeZone("Asia/Chongqing");
关于 getTimeZone(String id) 这种方式支持的全部id参数的取值，可以通过以下方式查找：
String[] ids = TimeZone.getAvailableIDs();
for (String id:ids)
System.out.printf(id+", ");
输出结果：
Etc/GMT+12, Etc/GMT+11, Pacific/Midway, Pacific/Niue, Pacific/Pago_Pago, Pacific/Samoa, US/Samoa, America/Adak, America/Atka, Etc/GMT+10, HST, Pacific/Honolulu, Pacific/Johnston, Pacific/Rarotonga, Pacific/Tahiti, SystemV/HST10, US/Aleutian, US/Hawaii, Pacific/Marquesas, AST, America/Anchorage, America/Juneau, America/Nome, America/Sitka, America/Yakutat, Etc/GMT+9, Pacific/Gambier, SystemV/YST9, SystemV/YST9YDT, US/Alaska, America/Dawson, America/Ensenada, America/Los_Angeles, America/Metlakatla, America/Santa_Isabel, America/Tijuana, America/Vancouver, America/Whitehorse, Canada/Pacific, Canada/Yukon, Etc/GMT+8, Mexico/BajaNorte, PST, PST8PDT, Pacific/Pitcairn, SystemV/PST8, SystemV/PST8PDT, US/Pacific, US/Pacific-New, America/Boise, America/Cambridge_Bay, America/Chihuahua, America/Creston, America/Dawson_Creek, America/Denver, America/Edmonton, America/Hermosillo, America/Inuvik, America/Mazatlan, America/Ojinaga, America/Phoenix, America/Shiprock, America/Yellowknife, Canada/Mountain, Etc/GMT+7, MST, MST7MDT, Mexico/BajaSur, Navajo, PNT, SystemV/MST7, SystemV/MST7MDT, US/Arizona, US/Mountain, America/Bahia_Banderas, America/Belize, America/Cancun, America/Chicago, America/Costa_Rica, America/El_Salvador, America/Guatemala, America/Indiana/Knox, America/Indiana/Tell_City, America/Knox_IN, America/Managua, America/Matamoros, America/Menominee, America/Merida, America/Mexico_City, America/Monterrey, America/North_Dakota/Beulah, America/North_Dakota/Center, America/North_Dakota/New_Salem, America/Rainy_River, America/Rankin_Inlet, America/Regina, America/Resolute, America/Swift_Current, America/Tegucigalpa, America/Winnipeg, CST, CST6CDT, Canada/Central, Canada/East-Saskatchewan, Canada/Saskatchewan, Chile/EasterIsland, Etc/GMT+6, Mexico/General, Pacific/Easter, Pacific/Galapagos, SystemV/CST6, SystemV/CST6CDT, US/Central, US/Indiana-Starke, America/Atikokan, America/Bogota, America/Cayman, America/Coral_Harbour, America/Detroit, America/Fort_Wayne, America/Grand_Turk, America/Guayaquil, America/Havana, America/Indiana/Indianapolis, America/Indiana/Marengo, America/Indiana/Petersburg, America/Indiana/Vevay, America/Indiana/Vincennes, America/Indiana/Winamac, America/Indianapolis, America/Iqaluit, America/Jamaica, America/Kentucky/Louisville, America/Kentucky/Monticello, America/Lima, America/Louisville, America/Montreal, America/Nassau, America/New_York, America/Nipigon, America/Panama, America/Pangnirtung, America/Port-au-Prince, America/Thunder_Bay, America/Toronto, Canada/Eastern, Cuba, EST, EST5EDT, Etc/GMT+5, IET, Jamaica, SystemV/EST5, SystemV/EST5EDT, US/East-Indiana, US/Eastern, US/Michigan, America/Caracas, America/Anguilla, America/Antigua, America/Argentina/San_Luis, America/Aruba, America/Asuncion, America/Barbados, America/Blanc-Sablon, America/Boa_Vista, America/Campo_Grande, America/Cuiaba, America/Curacao, America/Dominica, America/Eirunepe, America/Glace_Bay, America/Goose_Bay, America/Grenada, America/Guadeloupe, America/Guyana, America/Halifax, America/Kralendijk, America/La_Paz, America/Lower_Princes, America/Manaus, America/Marigot, America/Martinique, America/Moncton, America/Montserrat, America/Port_of_Spain, America/Porto_Acre, America/Porto_Velho, America/Puerto_Rico, America/Rio_Branco, America/Santiago, America/Santo_Domingo, America/St_Barthelemy, America/St_Kitts, America/St_Lucia, America/St_Thomas, America/St_Vincent, America/Thule, America/Tortola, America/Virgin, Antarctica/Palmer, Atlantic/Bermuda, Brazil/Acre, Brazil/West, Canada/Atlantic, Chile/Continental, Etc/GMT+4, PRT, SystemV/AST4, SystemV/AST4ADT, America/St_Johns, CNT, Canada/Newfoundland, AGT, America/Araguaina, America/Argentina/Buenos_Aires, America/Argentina/Catamarca, America/Argentina/ComodRivadavia, America/Argentina/Cordoba, America/Argentina/Jujuy, America/Argentina/La_Rioja, America/Argentina/Mendoza, America/Argentina/Rio_Gallegos, America/Argentina/Salta, America/Argentina/San_Juan, America/Argentina/Tucuman, America/Argentina/Ushuaia, America/Bahia, America/Belem, America/Buenos_Aires, America/Catamarca, America/Cayenne, America/Cordoba, America/Fortaleza, America/Godthab, America/Jujuy, America/Maceio, America/Mendoza, America/Miquelon, America/Montevideo, America/Paramaribo, America/Recife, America/Rosario, America/Santarem, America/Sao_Paulo, Antarctica/Rothera, Atlantic/Stanley, BET, Brazil/East, Etc/GMT+3, America/Noronha, Atlantic/South_Georgia, Brazil/DeNoronha, Etc/GMT+2, America/Scoresbysund, Atlantic/Azores, Atlantic/Cape_Verde, Etc/GMT+1, Africa/Abidjan, Africa/Accra, Africa/Bamako, Africa/Banjul, Africa/Bissau, Africa/Casablanca, Africa/Conakry, Africa/Dakar, Africa/El_Aaiun, Africa/Freetown, Africa/Lome, Africa/Monrovia, Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, Africa/Timbuktu, America/Danmarkshavn, Atlantic/Canary, Atlantic/Faeroe, Atlantic/Faroe, Atlantic/Madeira, Atlantic/Reykjavik, Atlantic/St_Helena, Eire, Etc/GMT, Etc/GMT+0, Etc/GMT-0, Etc/GMT0, Etc/Greenwich, Etc/UCT, Etc/UTC, Etc/Universal, Etc/Zulu, Europe/Belfast, Europe/Dublin, Europe/Guernsey, Europe/Isle_of_Man, Europe/Jersey, Europe/Lisbon, Europe/London, GB, GB-Eire, GMT, GMT0, Greenwich, Iceland, Portugal, UCT, UTC, Universal, WET, Zulu, Africa/Algiers, Africa/Bangui, Africa/Brazzaville, Africa/Ceuta, Africa/Douala, Africa/Kinshasa, Africa/Lagos, Africa/Libreville, Africa/Luanda, Africa/Malabo, Africa/Ndjamena, Africa/Niamey, Africa/Porto-Novo, Africa/Tunis, Africa/Windhoek, Arctic/Longyearbyen, Atlantic/Jan_Mayen, CET, ECT, Etc/GMT-1, Europe/Amsterdam, Europe/Andorra, Europe/Belgrade, Europe/Berlin, Europe/Bratislava, Europe/Brussels, Europe/Budapest, Europe/Copenhagen, Europe/Gibraltar, Europe/Ljubljana, Europe/Luxembourg, Europe/Madrid, Europe/Malta, Europe/Monaco, Europe/Oslo, Europe/Paris, Europe/Podgorica, Europe/Prague, Europe/Rome, Europe/San_Marino, Europe/Sarajevo, Europe/Skopje, Europe/Stockholm, Europe/Tirane, Europe/Vaduz, Europe/Vatican, Europe/Vienna, Europe/Warsaw, Europe/Zagreb, Europe/Zurich, MET, Poland, ART, Africa/Blantyre, Africa/Bujumbura, Africa/Cairo, Africa/Gaborone, Africa/Harare, Africa/Johannesburg, Africa/Kigali, Africa/Lubumbashi, Africa/Lusaka, Africa/Maputo, Africa/Maseru, Africa/Mbabane, Africa/Tripoli, Asia/Amman, Asia/Beirut, Asia/Damascus, Asia/Gaza, Asia/Hebron, Asia/Istanbul, Asia/Jerusalem, Asia/Nicosia, Asia/Tel_Aviv, CAT, EET, Egypt, Etc/GMT-2, Europe/Athens, Europe/Bucharest, Europe/Chisinau, Europe/Helsinki, Europe/Istanbul, Europe/Kiev, Europe/Mariehamn, Europe/Nicosia, Europe/Riga, Europe/Simferopol, Europe/Sofia, Europe/Tallinn, Europe/Tiraspol, Europe/Uzhgorod, Europe/Vilnius, Europe/Zaporozhye, Israel, Libya, Turkey, Africa/Addis_Ababa, Africa/Asmara, Africa/Asmera, Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Juba, Africa/Kampala, Africa/Khartoum, Africa/Mogadishu, Africa/Nairobi, Antarctica/Syowa, Asia/Aden, Asia/Baghdad, Asia/Bahrain, Asia/Kuwait, Asia/Qatar, Asia/Riyadh, EAT, Etc/GMT-3, Europe/Kaliningrad, Europe/Minsk, Indian/Antananarivo, Indian/Comoro, Indian/Mayotte, Asia/Riyadh87, Asia/Riyadh88, Asia/Riyadh89, Mideast/Riyadh87, Mideast/Riyadh88, Mideast/Riyadh89, Asia/Tehran, Iran, Asia/Baku, Asia/Dubai, Asia/Muscat, Asia/Tbilisi, Asia/Yerevan, Etc/GMT-4, Europe/Moscow, Europe/Samara, Europe/Volgograd, Indian/Mahe, Indian/Mauritius, Indian/Reunion, NET, W-SU, Asia/Kabul, Antarctica/Mawson, Asia/Aqtau, Asia/Aqtobe, Asia/Ashgabat, Asia/Ashkhabad, Asia/Dushanbe, Asia/Karachi, Asia/Oral, Asia/Samarkand, Asia/Tashkent, Etc/GMT-5, Indian/Kerguelen, Indian/Maldives, PLT, Asia/Calcutta, Asia/Colombo, Asia/Kolkata, IST, Asia/Kathmandu, Asia/Katmandu, Antarctica/Vostok, Asia/Almaty, Asia/Bishkek, Asia/Dacca, Asia/Dhaka, Asia/Qyzylorda, Asia/Thimbu, Asia/Thimphu, Asia/Yekaterinburg, BST, Etc/GMT-6, Indian/Chagos, Asia/Rangoon, Indian/Cocos, Antarctica/Davis, Asia/Bangkok, Asia/Ho_Chi_Minh, Asia/Hovd, Asia/Jakarta, Asia/Novokuznetsk, Asia/Novosibirsk, Asia/Omsk, Asia/Phnom_Penh, Asia/Pontianak, Asia/Saigon, Asia/Vientiane, Etc/GMT-7, Indian/Christmas, VST, Antarctica/Casey, Asia/Brunei, Asia/Choibalsan, Asia/Chongqing, Asia/Chungking, Asia/Harbin, Asia/Hong_Kong, Asia/Kashgar, Asia/Krasnoyarsk, Asia/Kuala_Lumpur, Asia/Kuching, Asia/Macao, Asia/Macau, Asia/Makassar, Asia/Manila, Asia/Shanghai, Asia/Singapore, Asia/Taipei, Asia/Ujung_Pandang, Asia/Ulaanbaatar, Asia/Ulan_Bator, Asia/Urumqi, Australia/Perth, Australia/West, CTT, Etc/GMT-8, Hongkong, PRC, Singapore, Australia/Eucla, Asia/Dili, Asia/Irkutsk, Asia/Jayapura, Asia/Pyongyang, Asia/Seoul, Asia/Tokyo, Etc/GMT-9, JST, Japan, Pacific/Palau, ROK, ACT, Australia/Adelaide, Australia/Broken_Hill, Australia/Darwin, Australia/North, Australia/South, Australia/Yancowinna, AET, Antarctica/DumontDUrville, Asia/Yakutsk, Australia/ACT, Australia/Brisbane, Australia/Canberra, Australia/Currie, Australia/Hobart, Australia/Lindeman, Australia/Melbourne, Australia/NSW, Australia/Queensland, Australia/Sydney, Australia/Tasmania, Australia/Victoria, Etc/GMT-10, Pacific/Chuuk, Pacific/Guam, Pacific/Port_Moresby, Pacific/Saipan, Pacific/Truk, Pacific/Yap, Australia/LHI, Australia/Lord_Howe, Antarctica/Macquarie, Asia/Sakhalin, Asia/Vladivostok, Etc/GMT-11, Pacific/Efate, Pacific/Guadalcanal, Pacific/Kosrae, Pacific/Noumea, Pacific/Pohnpei, Pacific/Ponape, SST, Pacific/Norfolk, Antarctica/McMurdo, Antarctica/South_Pole, Asia/Anadyr, Asia/Kamchatka, Asia/Magadan, Etc/GMT-12, Kwajalein, NST, NZ, Pacific/Auckland, Pacific/Fiji, Pacific/Funafuti, Pacific/Kwajalein, Pacific/Majuro, Pacific/Nauru, Pacific/Tarawa, Pacific/Wake, Pacific/Wallis, NZ-CHAT, Pacific/Chatham, Etc/GMT-13, MIT, Pacific/Apia, Pacific/Enderbury, Pacific/Fakaofo, Pacific/Tongatapu, Etc/GMT-14, Pacific/Kiritimati
例如，创建上面第2个打印值“Etc/GMT+11”对应的TimeZone。方法如下：
TimeZone tz = TimeZone.getTimeZone("Etc/GMT+11");
TimeZone的函数接口
// 构造函数
TimeZone()
Object clone()
synchronized static String[] getAvailableIDs()
synchronized static String[] getAvailableIDs(int offsetMillis)
int getDSTSavings()
synchronized static TimeZone getDefault()
final String getDisplayName(Locale locale)
String getDisplayName(boolean daylightTime, int style, Locale locale)
final String getDisplayName()
final String getDisplayName(boolean daylightTime, int style)
String getID()
abstract int getOffset(int era, int year, int month, int day, int dayOfWeek, int timeOfDayMillis)
int getOffset(long time)
abstract int getRawOffset()
synchronized static TimeZone getTimeZone(String id)
boolean hasSameRules(TimeZone timeZone)
abstract boolean inDaylightTime(Date time)
synchronized static void setDefault(TimeZone timeZone)
void setID(String id)
abstract void setRawOffset(int offsetMillis)
abstract boolean useDaylightTime()
2. TimeZone示例
下面通过示例演示在Date中使用TimeZone。
参考代码如下(TimeZoneTest.java)：
import java.text.DateFormat;
import java.util.Date;
import java.util.TimeZone;
/**
* TimeZone的测试程序
*
* @author skywang
* @email kuiwu-wang@163.com
*/
public class TimeZoneTest {
public static void main(String[] args) {
// 测试创建TimeZone对象的3种方法
showUsageOfTimeZones() ;
// 测试TimeZone的其它API
testOtherAPIs() ;
// 打印getTimeZone(String id)支持的所有id
//printAllTimeZones() ;
}
/**
* 测试创建TimeZone对象的3种方法
*/
public static void showUsageOfTimeZones() {
TimeZone tz;
// (01) 默认时区
tz = TimeZone.getDefault();
printDateIn(tz) ;
// (02) 设置时区为"GMT+08:00"
tz = TimeZone.getTimeZone("GMT+08:00");
printDateIn(tz) ;
// (03) 设置时区为""
tz = TimeZone.getTimeZone("Asia/Chongqing");
printDateIn(tz) ;
}
/**
* 打印 tz对应的日期/时间
*/
private static void printDateIn(TimeZone tz) {
// date为2013-09-19 14:22:30
Date date = new Date(113, 8, 19, 14, 22, 30);
// 获取默认的DateFormat，用于格式化Date
DateFormat df = DateFormat.getInstance();
// 设置时区为tz
df.setTimeZone(tz);
// 获取格式化后的字符串
String str = df.format(date);
System.out.println(tz.getID()+" :"+str);
}
/**
* 测试TimeZone的其它API
*/
public static void testOtherAPIs() {
// 默认时区
TimeZone tz = TimeZone.getDefault();
// 获取“id”
String id = tz.getID();
// 获取“显示名称”
String name = tz.getDisplayName();
// 获取“时间偏移”。相对于“本初子午线”的偏移，单位是ms。
int offset = tz.getRawOffset();
// 获取“时间偏移” 对应的小时
int gmt = offset/(3600*1000);
System.out.printf("id=%s, name=%s, offset=%s(ms), gmt=%s\n",
id, name, offset, gmt);
}
/**
* 打印getTimeZone(String id)支持的所有id
*/
public static void printAllTimeZones() {
String[] ids = TimeZone.getAvailableIDs();
for (String id:ids) {
//int offset = TimeZone.getTimeZone(avaIds[i]).getRawOffset();
//System.out.println(i+" "+avaIds[i]+" "+offset / (3600 * 1000) + "\t");
System.out.printf(id+", ");
}
System.out.println();
}
}