jsr310 - java 8 date and time api

JSR 310Date and Time API

©2015 Ady

-- everything about date and time in Java 8

JSR 310

https://jcp.org/en/jsr/detail?id=310

ClassesClass/Enum Y M D H m s Z toString()Instant √ 2014-12-16T09:42:57.054ZLocalDate √ √ √ 2014-12-16LocateDateTime √ √ √ √ √ √ 2014-12-16T17:42:57.196ZonedDateTime √ √ √ √ √ √ √ 2014-12-16T17:42:57.197+08:00[Asia/Chongqing]LocalTime √ √ √ 17:42:57.197MonthDay √ √ --12-16Year √ 2014YearMonth √ √ 2014-12Month √ DECEMBEROffsetDateTime √ √ √ √ √ √ √ 2014-12-16T17:42:57.231+08:00OffsetTime √ √ √ √ 17:42:57.232+08:00Duration √ PT3HPeriod √ √ √ P2014Y12M31D

LocalDate today = LocalDate.now();

LocalDate today = LocalDate.now();

int year = today.getYear();

int month = today.getMonthValue();

int day = today.getDayOfMonth();

LocalDate dayOfBirth = LocalDate.of(2015,10,14);

LocalDate date1 = LocalDate.of(2015,10,14);

if( date1.equals(today) ){

}

MonthDay birthday = MonthDay.of(12,4);

LocalTime = LocalTime.now();

LocalDateTime now = LocalDateTime.now();

System.out.println(now); //2015-10-14T11:23:50.083

LocalTime now = LocalTime.now();

LocalTime oneHour = now.plusHours(1);

LocalDate now = LocalDate.now();

System.out.println(now);

LocalDate nextMonth = now.plus(1, ChronoUnit.MONTHS);

System.out.println(nextMonth);

LocalDate now = LocalDate.now();

LocalDate next = LocalDate.of(2015,10,14);

boolean r = now.isBefore(next);

boolean r2 = now.isAfter(next);

YearMonth ym = YearMonth.of(2016, Month.FEBRUARY);

System.out.println(ym.isLeapYear()); // true

System.out.println(ym.lengthOfMonth()); // 29

System.out.println(ym.lengthOfYear()); // 366

.

LocalDate today = LocalDate.now();

LocalDate birthday = LocalDate.of(2012,10,15);

Period p = Period.between(birthday, today);

System.out.println(p); // P2Y11M29D

LocalDate birthday = LocalDate.of(2012, 10, 15);

LocalDate today = LocalDate.now();

System.out.println(ChronoUnit.DAYS.between(birthday, today)); //1094

System.out.println(ChronoUnit.MONTHS.between(birthday, today)); //35

LocalDateTime now = LocalDateTime.now();

LocalDateTime birthDay = LocalDateTime.of(2012,10,15,9,30);

Duration d = Duration.between(birthDay,now);

System.out.println(d); //PT26258H17M34.68S

System.out.println(d.toDays()); //1094

ZonedDateTime now = ZonedDateTime.now();

ZoneId parisZoneId = ZoneId.of("Europe/Paris");

ZonedDateTime parisNow = now.withZoneSameInstant(parisZoneId);

System.out.println("Beijing: " + now); //Beijing: 2015-10-14T10:46:23.397+08:00[Asia/Shanghai]

System.out.println("Paris: " + parisNow);//Paris: 2015-10-14T04:46:23.397+02:00[Europe/Paris]

Instant now = Instant.now();

System.out.println(now.toString()); // 2015-10-14T03:18:52.324Z

System.out.println(now.toEpochMilli()); // 1444792732324

System.out.println(now.getEpochSecond()); // 1444792732

System.out.println(Clock.systemUTC().millis()); // 1444792912772

System.out.println(Clock.systemDefaultZone().millis()); // 1444792912772

System.out.println(System.currentTimeMillis()); //1444792912772

LocalDateTime now = LocalDateTime.now();

System.out.println(now); //2015-10-14T11:23:50.083

DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

System.out.println(now.format(format)); //2015-10-14 11:23:50

DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

LocalDateTime dtime = LocalDateTime.parse("2015-10-14 11:23:50", format);

Main Methodnow static factory instance of now LocalDateTime.now()

of static factory create instance LocalDate.of(2014,12,16)

from static factory convert input to target YearMonth.from(localDate)

parse static factory parse string to target YearMonth.parse("2014-12")

format instance format instance to string LocalDate.format(DateTimeFormatter.ISO_DATE)

get instance get a part LocalDate.get(ChronoField.DAY_OF_YEAR)

is instance compare with LocalDate.isBefore/isAfter/isEqual

with instance return copy with changed LocalDate.with(ChronoField.YEAR,2016)

plus instance return copy with added LocalDate.plusYears(1)

minus instance return copy with subtracted LocalDateTime.minusMonths(1)

to instance convert instance to target LocalDateTime.toLocalTime()

at instance combine two instance LocalDate.atTime(12,30,0)

Date now = new Date();

Instant ins = now.toInstant();

Date oldDate = new Date(ins.toEpochMilli());

Date oldDate2 = Date.from(ins);

Instant ins2 = LocalDateTime.now().toInstant(ZoneOffset.UTC);

Timestamp t = Timestamp.valueOf(LocalDateTime.now());

Instant ins3 = t.toInstant();

Instant

1

2/Instants 1444792732324

/Periods P2Y11M29D

/Dates 2015-10-14

/Times 11:42:45

/Timezones +08:00/Asia/Shanghai

/Durations PT26258H17M34.68S

https://zh.wikipedia.org/wiki/ISO_8601

3

Instant

LocalDate

LocalTime

LocalDateTime

ZonedDateTime

4ZoneId

ChronoUnit

DateTimeFormatter

Duration

Period

OffsetDateTime

The End

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