JDK8新增时间

时间"/>

JDK8新增时间

目录

LocalDate/LocalTime/LocalDateTime

ZoneId：时区

​编辑ZonedDateTime:带时区的时间

Instant时间戳

DateTimeFormatter格式化器

Period（一段时间）

Duration （持续时间）●可以用于计算两个时间对象相差的天数、小时数、分数、秒数、纳秒数；支持 LocalTime 、 LocalDateTime 、 Instant 等时间

为什么要学JDK8新增的时间 

LocalDate/LocalTime/LocalDateTime

LocalDate ：代表本地日期（年、月、日、星期）
 LocalTime ：代表本地时间（时、分、秒、纳秒）
 LocalDateTime ：代表本地日期、时间（年、月、日、星期、时、分、秒、纳秒）

它们获取对象的方案

LocalDate的常用API（年、月、日、星期）

LocalTime的常用API（时、分、秒、纳秒）

 LocalDateTime 的常用API（年、月、日、星期、时、分、秒、纳秒）

package com.xinbao.d4_jdk8_time;import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;public class Test_LocalDateTime {public static void main(String[] args) {//0、获取本地日期和时间对象LocalDateTime ldt = LocalDateTime.now();System.out.println(ldt);//1、可以获取日期和时间的全部信息int year = ldt.getYear();int month = ldt.getMonthValue();int day = ldt.getDayOfMonth();int dayOfYear = ldt.getDayOfYear();int second = ldt.getSecond();int nano = ldt.getNano();//纳秒//2、修改时间信息(不可变对象)LocalDateTime ldt2 = ldt.withYear(2022);LocalDateTime ldt3 = ldt.withMonth(7).withDayOfMonth(10);System.out.println(ldt2);System.out.println(ldt3);//3、加LocalDateTime ldt4 = ldt.plusDays(360);System.out.println(ldt4);//4、减LocalDateTime ldt5 = ldt.minusHours(5);System.out.println(ldt5);//5、获取指定日期时间的对象LocalDateTime ldt6 = LocalDateTime.of(2002,9,16,15,55);System.out.println(ldt6);//6、判断对象是否相等，前后System.out.println(ldt6.equals(ldt));System.out.println(ldt6.isAfter(ldt));System.out.println(ldt6.isBefore(ldt));//7、可以把LocalDateTime转换成LocalDate和LocalTimeLocalDate date = ldt.toLocalDate();LocalTime time = ldt.toLocalTime();LocalDateTime ldtldt = LocalDateTime.of(date,time);System.out.println(date);System.out.println(time);System.out.println(ldtldt);}
}

E:\JVsoft\Java\jdk-17\bin\java.exe -javaagent:E:\JVsoft\IntelliJIDEA2021.1.1\lib\idea_rt.jar=9785:E:\JVsoft\IntelliJIDEA2021.1.1\bin -Dfile.encoding=UTF-8 -classpath E:\JVsoft\code\out\production\api-app2 com.xinbao.d4_jdk8_time.Test_LocalDateTime
2023-09-24T16:47:29.223337900
2022-09-24T16:47:29.223337900
2023-07-10T16:47:29.223337900
2024-09-18T16:47:29.223337900
2023-09-24T11:47:29.223337900
2002-09-16T15:55
false
false
true
2023-09-24
16:47:29.223337900
2023-09-24T16:47:29.223337900Process finished with exit code 0

ZoneId：时区

ZonedDateTime:带时区的时间

package com.xinbao.d4_jdk8_time;import java.time.Clock;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Calendar;
import java.util.TimeZone;public class Test4_ZoneId {public static void main(String[] args) {//1、ZoneId的常见方法//获取系统默认时区ZoneId zoneId = ZoneId.systemDefault();System.out.println(zoneId.getId());System.out.println(zoneId);//获取java支持的全部时区  //ctrl+f搜索System.out.println(ZoneId.getAvailableZoneIds());//把某个时区id封装成ZoneId对象ZoneId zoneId1 = ZoneId.of("America/New_York");//2、ZoneDateTime：带时区的时间//获取某个时区的ZoneDateTime对象ZonedDateTime now = ZonedDateTime.now(zoneId1);System.out.println(now);//差12小时//世界标准时间（本初子午线）ZonedDateTime now2 = ZonedDateTime.now(Clock.systemUTC());System.out.println(now2);//差8小时//获取系统默认时区的ZoneDateTime对象ZonedDateTime now3 = ZonedDateTime.now();System.out.println(now3);Calendar instance = Calendar.getInstance(TimeZone.getTimeZone(zoneId1));System.out.println(instance);}
}

E:\JVsoft\Java\jdk-17\bin\java.exe -javaagent:E:\JVsoft\IntelliJIDEA2021.1.1\lib\idea_rt.jar=10180:E:\JVsoft\IntelliJIDEA2021.1.1\bin -Dfile.encoding=UTF-8 -classpath E:\JVsoft\code\out\production\api-app2 com.xinbao.d4_jdk8_time.Test4_ZoneId
Asia/Shanghai
Asia/Shanghai
[Asia/Aden, America/Cuiaba, Etc/GMT+9, Etc/GMT+8, Africa/Nairobi, America/Marigot, Asia/Aqtau, Pacific/Kwajalein, America/El_Salvador, Asia/Pontianak, Africa/Cairo, Pacific/Pago_Pago, Africa/Mbabane, Asia/Kuching, Pacific/Honolulu, Pacific/Rarotonga, America/Guatemala, Australia/Hobart, Europe/London, America/Belize, America/Panama, Asia/Chungking, America/Managua, America/Indiana/Petersburg, Asia/Yerevan, Europe/Brussels, GMT, Europe/Warsaw, America/Chicago, Asia/Kashgar, Chile/Continental, Pacific/Yap, CET, Etc/GMT-1, Etc/GMT-0, Europe/Jersey, America/Tegucigalpa, Etc/GMT-5, Europe/Istanbul, America/Eirunepe, Etc/GMT-4, America/Miquelon, Etc/GMT-3, Europe/Luxembourg, Etc/GMT-2, Etc/GMT-9, America/Argentina/Catamarca, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Europe/Zaporozhye, Canada/Yukon, Canada/Atlantic, Atlantic/St_Helena, Australia/Tasmania, Libya, Europe/Guernsey, America/Grand_Turk, Asia/Samarkand, America/Argentina/Cordoba, Asia/Phnom_Penh, Africa/Kigali, Asia/Almaty, US/Alaska, Asia/Dubai, Europe/Isle_of_Man, America/Araguaina, Cuba, Asia/Novosibirsk, America/Argentina/Salta, Etc/GMT+3, Africa/Tunis, Etc/GMT+2, Etc/GMT+1, Pacific/Fakaofo, Africa/Tripoli, Etc/GMT+0, Israel, Africa/Banjul, Etc/GMT+7, Indian/Comoro, Etc/GMT+6, Etc/GMT+5, Etc/GMT+4, Pacific/Port_Moresby, US/Arizona, Antarctica/Syowa, Indian/Reunion, Pacific/Palau, Europe/Kaliningrad, America/Montevideo, Africa/Windhoek, Asia/Karachi, Africa/Mogadishu, Australia/Perth, Brazil/East, Etc/GMT, Asia/Chita, Pacific/Easter, Antarctica/Davis, Antarctica/McMurdo, Asia/Macao, America/Manaus, Africa/Freetown, Europe/Bucharest, Asia/Tomsk, America/Argentina/Mendoza, Asia/Macau, Europe/Malta, Mexico/BajaSur, Pacific/Tahiti, Africa/Asmera, Europe/Busingen, America/Argentina/Rio_Gallegos, Africa/Malabo, Europe/Skopje, America/Catamarca, America/Godthab, Europe/Sarajevo, Australia/ACT, GB-Eire, Africa/Lagos, America/Cordoba, Europe/Rome, Asia/Dacca, Indian/Mauritius, Pacific/Samoa, America/Regina, America/Fort_Wayne, America/Dawson_Creek, Africa/Algiers, Europe/Mariehamn, America/St_Johns, America/St_Thomas, Europe/Zurich, America/Anguilla, Asia/Dili, America/Denver, Africa/Bamako, Europe/Saratov, GB, Mexico/General, Pacific/Wallis, Europe/Gibraltar, Africa/Conakry, Africa/Lubumbashi, Asia/Istanbul, America/Havana, NZ-CHAT, Asia/Choibalsan, America/Porto_Acre, Asia/Omsk, Europe/Vaduz, US/Michigan, Asia/Dhaka, America/Barbados, Europe/Tiraspol, Atlantic/Cape_Verde, Asia/Yekaterinburg, America/Louisville, Pacific/Johnston, Pacific/Chatham, Europe/Ljubljana, America/Sao_Paulo, Asia/Jayapura, America/Curacao, Asia/Dushanbe, America/Guyana, America/Guayaquil, America/Martinique, Portugal, Europe/Berlin, Europe/Moscow, Europe/Chisinau, America/Puerto_Rico, America/Rankin_Inlet, Pacific/Ponape, Europe/Stockholm, Europe/Budapest, America/Argentina/Jujuy, Australia/Eucla, Asia/Shanghai, Universal, Europe/Zagreb, America/Port_of_Spain, Europe/Helsinki, Asia/Beirut, Asia/Tel_Aviv, Pacific/Bougainville, US/Central, Africa/Sao_Tome, Indian/Chagos, America/Cayenne, Asia/Yakutsk, Pacific/Galapagos, Australia/North, Europe/Paris, Africa/Ndjamena, Pacific/Fiji, America/Rainy_River, Indian/Maldives, Australia/Yancowinna, SystemV/AST4, Asia/Oral, America/Yellowknife, Pacific/Enderbury, America/Juneau, Australia/Victoria, America/Indiana/Vevay, Asia/Tashkent, Asia/Jakarta, Africa/Ceuta, Asia/Barnaul, America/Recife, America/Buenos_Aires, America/Noronha, America/Swift_Current, Australia/Adelaide, America/Metlakatla, Africa/Djibouti, America/Paramaribo, Asia/Qostanay, Europe/Simferopol, Europe/Sofia, Africa/Nouakchott, Europe/Prague, America/Indiana/Vincennes, Antarctica/Mawson, America/Kralendijk, Antarctica/Troll, Europe/Samara, Indian/Christmas, America/Antigua, Pacific/Gambier, America/Indianapolis, America/Inuvik, America/Iqaluit, Pacific/Funafuti, UTC, Antarctica/Macquarie, Canada/Pacific, America/Moncton, Africa/Gaborone, Pacific/Chuuk, Asia/Pyongyang, America/St_Vincent, Asia/Gaza, Etc/Universal, PST8PDT, Atlantic/Faeroe, Asia/Qyzylorda, Canada/Newfoundland, America/Kentucky/Louisville, America/Yakutat, America/Ciudad_Juarez, Asia/Ho_Chi_Minh, Antarctica/Casey, Europe/Copenhagen, Africa/Asmara, Atlantic/Azores, Europe/Vienna, ROK, Pacific/Pitcairn, America/Mazatlan, Australia/Queensland, Pacific/Nauru, Europe/Tirane, Asia/Kolkata, SystemV/MST7, Australia/Canberra, MET, Australia/Broken_Hill, Europe/Riga, America/Dominica, Africa/Abidjan, America/Mendoza, America/Santarem, Kwajalein, America/Asuncion, Asia/Ulan_Bator, NZ, America/Boise, Australia/Currie, EST5EDT, Pacific/Guam, Pacific/Wake, Atlantic/Bermuda, America/Costa_Rica, America/Dawson, Asia/Chongqing, Eire, Europe/Amsterdam, America/Indiana/Knox, America/North_Dakota/Beulah, Africa/Accra, Atlantic/Faroe, Mexico/BajaNorte, America/Maceio, Etc/UCT, Pacific/Apia, GMT0, America/Atka, Pacific/Niue, Australia/Lord_Howe, Europe/Dublin, Pacific/Truk, MST7MDT, America/Monterrey, America/Nassau, America/Jamaica, Asia/Bishkek, America/Atikokan, Atlantic/Stanley, Australia/NSW, US/Hawaii, SystemV/CST6, Indian/Mahe, Asia/Aqtobe, America/Sitka, Asia/Vladivostok, Africa/Libreville, Africa/Maputo, Zulu, America/Kentucky/Monticello, Africa/El_Aaiun, Africa/Ouagadougou, America/Coral_Harbour, Pacific/Marquesas, Brazil/West, America/Aruba, America/North_Dakota/Center, America/Cayman, Asia/Ulaanbaatar, Asia/Baghdad, Europe/San_Marino, America/Indiana/Tell_City, America/Tijuana, Pacific/Saipan, SystemV/YST9, Africa/Douala, America/Chihuahua, America/Ojinaga, Asia/Hovd, America/Anchorage, Chile/EasterIsland, America/Halifax, Antarctica/Rothera, America/Indiana/Indianapolis, US/Mountain, Asia/Damascus, America/Argentina/San_Luis, America/Santiago, Asia/Baku, America/Argentina/Ushuaia, Atlantic/Reykjavik, Africa/Brazzaville, Africa/Porto-Novo, America/La_Paz, Antarctica/DumontDUrville, Asia/Taipei, Antarctica/South_Pole, Asia/Manila, Asia/Bangkok, Africa/Dar_es_Salaam, Poland, Atlantic/Madeira, Antarctica/Palmer, America/Thunder_Bay, Africa/Addis_Ababa, Asia/Yangon, Europe/Uzhgorod, Brazil/DeNoronha, Asia/Ashkhabad, Etc/Zulu, America/Indiana/Marengo, America/Creston, America/Punta_Arenas, America/Mexico_City, Antarctica/Vostok, Asia/Jerusalem, Europe/Andorra, US/Samoa, PRC, Asia/Vientiane, Pacific/Kiritimati, America/Matamoros, America/Blanc-Sablon, Asia/Riyadh, Iceland, Pacific/Pohnpei, Asia/Ujung_Pandang, Atlantic/South_Georgia, Europe/Lisbon, Asia/Harbin, Europe/Oslo, Asia/Novokuznetsk, CST6CDT, Atlantic/Canary, America/Knox_IN, Asia/Kuwait, SystemV/HST10, Pacific/Efate, Africa/Lome, America/Bogota, America/Menominee, America/Adak, Pacific/Norfolk, Europe/Kirov, America/Resolute, Pacific/Kanton, Pacific/Tarawa, Africa/Kampala, Asia/Krasnoyarsk, Greenwich, SystemV/EST5, America/Edmonton, Europe/Podgorica, Australia/South, Canada/Central, Africa/Bujumbura, America/Santo_Domingo, US/Eastern, Europe/Minsk, Pacific/Auckland, Africa/Casablanca, America/Glace_Bay, Canada/Eastern, Asia/Qatar, Europe/Kiev, Singapore, Asia/Magadan, SystemV/PST8, America/Port-au-Prince, Europe/Belfast, America/St_Barthelemy, Asia/Ashgabat, Africa/Luanda, America/Nipigon, Atlantic/Jan_Mayen, Brazil/Acre, Asia/Muscat, Asia/Bahrain, Europe/Vilnius, America/Fortaleza, Etc/GMT0, US/East-Indiana, America/Hermosillo, America/Cancun, Africa/Maseru, Pacific/Kosrae, Africa/Kinshasa, Asia/Kathmandu, Asia/Seoul, Australia/Sydney, America/Lima, Australia/LHI, America/St_Lucia, Europe/Madrid, America/Bahia_Banderas, America/Montserrat, Asia/Brunei, America/Santa_Isabel, Canada/Mountain, America/Cambridge_Bay, Asia/Colombo, Australia/West, Indian/Antananarivo, Australia/Brisbane, Indian/Mayotte, US/Indiana-Starke, Asia/Urumqi, US/Aleutian, Europe/Volgograd, America/Lower_Princes, America/Vancouver, Africa/Blantyre, America/Rio_Branco, America/Danmarkshavn, America/Detroit, America/Thule, Africa/Lusaka, Asia/Hong_Kong, Iran, America/Argentina/La_Rioja, Africa/Dakar, SystemV/CST6CDT, America/Tortola, America/Porto_Velho, Asia/Sakhalin, Etc/GMT+10, America/Scoresbysund, Asia/Kamchatka, Asia/Thimbu, Africa/Harare, Etc/GMT+12, Etc/GMT+11, Navajo, America/Nome, Europe/Tallinn, Turkey, Africa/Khartoum, Africa/Johannesburg, Africa/Bangui, Europe/Belgrade, Jamaica, Africa/Bissau, Asia/Tehran, WET, Europe/Astrakhan, Africa/Juba, America/Campo_Grande, America/Belem, Etc/Greenwich, Asia/Saigon, America/Ensenada, Pacific/Midway, America/Jujuy, Africa/Timbuktu, America/Bahia, America/Goose_Bay, America/Virgin, America/Pangnirtung, Asia/Katmandu, America/Phoenix, Africa/Niamey, America/Whitehorse, Pacific/Noumea, Asia/Tbilisi, Europe/Kyiv, America/Montreal, Asia/Makassar, America/Argentina/San_Juan, Hongkong, UCT, Asia/Nicosia, America/Indiana/Winamac, SystemV/MST7MDT, America/Argentina/ComodRivadavia, America/Boa_Vista, America/Grenada, Asia/Atyrau, Australia/Darwin, Asia/Khandyga, Asia/Kuala_Lumpur, Asia/Famagusta, Asia/Thimphu, Asia/Rangoon, Europe/Bratislava, Asia/Calcutta, America/Argentina/Tucuman, Asia/Kabul, Indian/Cocos, Japan, Pacific/Tongatapu, America/New_York, Etc/GMT-12, Etc/GMT-11, America/Nuuk, Etc/GMT-10, SystemV/YST9YDT, Europe/Ulyanovsk, Etc/GMT-14, Etc/GMT-13, W-SU, America/Merida, EET, America/Rosario, Canada/Saskatchewan, America/St_Kitts, Arctic/Longyearbyen, America/Fort_Nelson, America/Caracas, America/Guadeloupe, Asia/Hebron, Indian/Kerguelen, SystemV/PST8PDT, Africa/Monrovia, Asia/Ust-Nera, Egypt, Asia/Srednekolymsk, America/North_Dakota/New_Salem, Asia/Anadyr, Australia/Melbourne, Asia/Irkutsk, America/Shiprock, America/Winnipeg, Europe/Vatican, Asia/Amman, Etc/UTC, SystemV/AST4ADT, Asia/Tokyo, America/Toronto, Asia/Singapore, Australia/Lindeman, America/Los_Angeles, SystemV/EST5EDT, Pacific/Majuro, America/Argentina/Buenos_Aires, Europe/Nicosia, Pacific/Guadalcanal, Europe/Athens, US/Pacific, Europe/Monaco]
2023-09-24T07:19:37.724470600-04:00[America/New_York]
2023-09-24T11:19:37.724470600Z
2023-09-24T19:19:37.724470600+08:00[Asia/Shanghai]
java.util.GregorianCalendar[time=1695554377734,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/New_York",offset=-18000000,dstSavings=3600000,useDaylight=true,transitions=235,lastRule=java.util.SimpleTimeZone[id=America/New_York,offset=-18000000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2023,MONTH=8,WEEK_OF_YEAR=39,WEEK_OF_MONTH=5,DAY_OF_MONTH=24,DAY_OF_YEAR=267,DAY_OF_WEEK=1,DAY_OF_WEEK_IN_MONTH=4,AM_PM=0,HOUR=7,HOUR_OF_DAY=7,MINUTE=19,SECOND=37,MILLISECOND=734,ZONE_OFFSET=-18000000,DST_OFFSET=3600000]Process finished with exit code 0

Instant时间戳

时间线上的某个时刻／时间戳
.通过获取 Instant 的对象可以拿到此刻的时间，该时间由两部分组成：从1970-01-01 00:00:00开始走到此刻的总秒数＋不到1秒的纳秒数

●作用：可以用来记录代码的执行时间，或用于记录用户操作某个事件的时间点。
传统的 Date 类，只能精确到毫秒，并且是可变对象；
新增的 Instant 类，可以精确到纳秒，并且是不可变对象，推荐用 Instant 代替 Date

package com.xinbao.d4_jdk8_time;import java.time.Instant;public class Test5_Instant {public static void main(String[] args) {//1、创建Instant对象，获取此刻的信息Instant now = Instant.now();System.out.println(now);//2、获取总秒数long second = now.getEpochSecond();System.out.println(second);//3、获取不到1秒的纳秒数int nano = now.getNano();System.out.println(nano);System.out.println(now);//4、加减Instant instant = now.plusNanos(666);System.out.println(instant);System.out.println(now.minusSeconds(999));//Instant对象的作用：做代码的性能分析，或者记录用户的操作时间点Instant now1 = Instant.now();//code working...Instant now2 = Instant.now();}
}

E:\JVsoft\Java\jdk-17\bin\java.exe -javaagent:E:\JVsoft\IntelliJIDEA2021.1.1\lib\idea_rt.jar=10301:E:\JVsoft\IntelliJIDEA2021.1.1\bin -Dfile.encoding=UTF-8 -classpath E:\JVsoft\code\out\production\api-app2 com.xinbao.d4_jdk8_time.Test5_Instant
2023-09-24T11:47:41.402642800Z
1695556061
402642800
2023-09-24T11:47:41.402642800Z
2023-09-24T11:47:41.402643466Z
2023-09-24T11:31:02.402642800ZProcess finished with exit code 0

DateTimeFormatter格式化器

用于时间的格式化和解析

package com.xinbao.d4_jdk8_time;import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;public class Test6_DataTimeFormatter {public static void main(String[] args) {//1、创建一个日期时间格式化器对象出来DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy年MM月dd日 HH:mm:ss");//2、对时间进行格式化LocalDateTime now = LocalDateTime.now();System.out.println(now);String rs = formatter.format(now);//正向格式化System.out.println(rs);String rs2 = now.format(formatter);//反向格式化System.out.println(rs2);//4、解析时间，一般使用LocalDateTime提供的解析方法来解析String dateStr = "2020年09月16日 12:12:10";LocalDateTime ldt = LocalDateTime.parse(dateStr,formatter);System.out.println(ldt);}
}

E:\JVsoft\Java\jdk-17\bin\java.exe -javaagent:E:\JVsoft\IntelliJIDEA2021.1.1\lib\idea_rt.jar=10412:E:\JVsoft\IntelliJIDEA2021.1.1\bin -Dfile.encoding=UTF-8 -classpath E:\JVsoft\code\out\production\api-app2 com.xinbao.d4_jdk8_time.Test6_DataTimeFormatter
2023-09-24T20:08:26.834295200
2023年09月24日 20:08:26
2023年09月24日 20:08:26
2020-09-16T12:12:10Process finished with exit code 0

Period（一段时间）

可以用于计算两个LocalDate对象相差的年数、月数、天数

package com.xinbao.d4_jdk8_time;import java.time.LocalDate;
import java.time.Period;public class Test7_Period {public static void main(String[] args) {LocalDate start = LocalDate.of(2099,8,5);LocalDate end = LocalDate.of(2099,8,15);//1、创建Period对象，封装两个日期对象Period period = Period.between(start,end);//2、通过Period对象获取两个日期对象相差的信息System.out.println(period.getYears());//0System.out.println(period.getMonths());//0System.out.println(period.getDays());//10}
}

Duration （持续时间）

●可以用于计算两个时间对象相差的天数、小时数、分数、秒数、纳秒数；支持 LocalTime 、 LocalDateTime 、 Instant 等时间

package com.xinbao.d4_jdk8_time;import java.time.Duration;
import java.time.LocalDateTime;public class Test8_Duration {public static void main(String[] args) {LocalDateTime start = LocalDateTime.of(2088,12,24,23,25,56);LocalDateTime end = LocalDateTime.of(2088,12,24,23,28,36);Duration duration = Duration.between(start,end);System.out.println(duration.toDays());//0System.out.println(duration.toHours());//0System.out.println(duration.toMinutes());//2System.out.println(duration.toSeconds());//160System.out.println(duration.toMillis());//160000System.out.println(duration.toNanos());//160 000 000 000}
}