Java 8 time and date

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package lime.java1_8.time;
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAdjusters;
import java.util.Date;
* *
* @Author liangmy
* @Date 2018/7/16
* /
public class Localdatetime {
public static void main(String[] args) {
//Take the current date:
LocalDate today = LocalDate.now();
System.out.println(today);
//According to the date, December is 12:
LocalDate crischristmas = LocalDate.of(2018, 07, 16);
System.out.println(crischristmas);
//Based on string:
LocalDate endOfFeb = LocalDate.parse("2018-07-16");
System.out.println(endOfFeb);
//Take the first day of this month:
LocalDate firstDayOfThisMonth = today.with(TemporalAdjusters.firstDayOfMonth());
System.out.println(firstDayOfThisMonth);
//Take the 2nd day of this month:
LocalDate secondDayOfThisMonth = today.withDayOfMonth(2);
System.out.println(secondDayOfThisMonth);
//Take the last day of the month, no longer need to calculate whether it is 28, 29, 30 or 31:
LocalDate lastDayOfThisMonth = today.with(TemporalAdjusters.lastDayOfMonth());
System.out.println(lastDayOfThisMonth);
//Next day:
LocalDate firstDayOf2018 = lastDayOfThisMonth.plusDays(1);
System.out.println(firstDayOf2018);
//On the first Monday of January 2018, a lot of brain cells will die in the calendar:
LocalDate firstMondayOf2018 = today.withMonth(1).with(TemporalAdjusters.firstInMonth(DayOfWeek.MONDAY));
System.out.println(firstMondayOf2018);
//Localtime contains milliseconds:
LocalTime now = LocalTime.now();
System.out.println(now);
//Clear milliseconds:
LocalTime nowWithNano0 = LocalTime.now().withNano(0);
System.out.println(nowWithNano0);
//Construction time:
LocalTime zeroHM = LocalTime.of(0,0);
System.out.println(zeroHM);
LocalTime zeroHMS = LocalTime.of(0, 0, 0);
System.out.println(zeroHMS);
LocalTime zeroHMSN = LocalTime.of(0, 0, 0, 0);
System.out.println(zeroHMSN);
LocalTime midHMStr = LocalTime.parse("12:00");
System.out.println(midHMStr);
LocalTime midHMSStr = LocalTime.parse("12:00:00");
System.out.println(midHMSStr);
//Create an instance of locatdatetime
LocalDateTime localDateTimeNow = LocalDateTime.now();
System.out.println(localDateTimeNow);
LocalDateTime localDateTimeOf = LocalDateTime.of(2018,1, 1, 00, 00, 00, 12);
System.out.println(localDateTimeOf);
//Instant: time stamp
//UTC time zone is used by default
Instant insNow = Instant.now(); 
System.out.println(insNow);
OffsetDateTime insUTC8 = insNow.atOffset(ZoneOffset.ofHours(8));
System.out.println(insUTC8);
System.out.println(insNow.getNano());
//Get UTC time zone timestamp of 5 seconds after midnight on January 1, 1970
Instant ofEpochSecond = Instant.ofEpochSecond(5);
System.out.println(ofEpochSecond);
//Duration: used to calculate two "time" intervals
//Period: used to calculate two "date" intervals
LocalTime startTime = LocalTime.now();
LocalTime endTime = startTime.plusHours(1).plusMinutes(2).plusSeconds(3).plusNanos(4);
Duration duration = Duration.between(startTime, endTime);
System.out.println(duration);
System.out.println(duration.getUnits());
System.out.println(duration.getSeconds());
System.out.println(duration.getNano());
LocalDate startDay = LocalDate.now();
LocalDate endDay = startDay.plusYears(1).plusMonths(2).plusDays(3).plusWeeks(4);
Period period = Period.between(startDay, endDay);
System.out.println(period);
System.out.println(period.getYears());
System.out.println(period.getMonths());
System.out.println(period.getDays());
System.out.println(period.getUnits());
System.out.println(period.getChronology());
//Temporaladjuster: time corrector
LocalDate with = today.with(TemporalAdjusters.next(DayOfWeek.MONDAY));
System.out.println(with);
//DateTimeFormatter
//Predefined standard formats
//Locale related formats
//Custom format
Datetimeformatter datetimeformatter = datetimeformatter.ofpattern ("yyyy MM DD HH: mm: SS e");
String localDateTime = LocalDateTime.now().format(dateTimeFormatter);
System.out.println(localDateTime);
//Time zone processing
//ZonedDate、 ZonedTime、 ZonedDateTime
//Each time zone corresponds to the ID, and the region ID is in the format of "{region} / {City}" Asia / Shanghai
//Zoneid: this class contains all time zone information
//Getavailablezones(): all time zone and time zone information can be obtained
//Of (ID): get zoneid object with specified time zone information
LocalDateTime zoneAsiaShanghai = LocalDateTime.now(ZoneId.of("Asia/Shanghai"));
System.out.println(zoneAsiaShanghai);
LocalDateTime zoneSystemDefault = LocalDateTime.now(ZoneId.systemDefault());
System.out.println(zoneSystemDefault);
//from(Instant instant)
//toInstant()
// Long - Instant
Instant instant = Instant.ofEpochMilli(System.currentTimeMillis());
System.out.println(instant);
//Instant - Long
Long timestamp = Instant.now().toEpochMilli();
System.out.println(timestamp);
// Date - LocalDateTime
LocalDateTime date2LocalDateTime = LocalDateTime.ofInstant(new Date().toInstant(), ZoneId.systemDefault());
System.out.println(date2LocalDateTime);
// Date - LocalDate
LocalDate date2LocalDate = date2LocalDateTime.toLocalDate();
System.out.println(date2LocalDate);
// Date - LocalTime
LocalTime date2LocalTime = date2LocalDateTime.toLocalTime();
System.out.println(date2LocalTime);
// LocalDateTime - Date
Date localDateTime2Date = Date.from(date2LocalDateTime.toInstant(ZoneOffset.ofHours(8)));
System.out.println(localDateTime2Date);
// LocalDate - Date
Date localDate2Date = Date.from(date2LocalDate.atStartOfDay().toInstant(ZoneOffset.ofHours(8)));
System.out.println(localDate2Date);
// LocalTime - Date
Date localTime2Date = Date.from(LocalDateTime.of(LocalDate.now(), date2LocalTime).toInstant(ZoneOffset.ofHours(8)));
System.out.println(localTime2Date);
}
} 

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Java 8 time and date