Java 8 – 期間と期間の例
Java 8の
Duration
、` Period`、 `ChronoUnit`オブジェクトを使って日付の違いを調べる方法を示す例はほとんどありません。
-
継続時間 – 秒とナノ秒単位の時間を測定します.
-
期間 – 年、月、日で時間を測定します.
1.継続時間の例
2つの
LocalDateTime`の差秒数を調べる
java.time.Duration`の例
DurationExample.java
package com.mkyong.time;
import java.time.Duration;
import java.time.LocalDateTime;
import java.time.Month;
import java.time.temporal.ChronoUnit;
public class DurationExample {
public static void main(String[]args) {
//Creating Durations
System.out.println("--- Examples --- ");
Duration oneHours = Duration.ofHours(1);
System.out.println(oneHours.getSeconds() + " seconds");
Duration oneHours2 = Duration.of(1, ChronoUnit.HOURS);
System.out.println(oneHours2.getSeconds() + " seconds");
//Test Duration.between
System.out.println("\n--- Duration.between --- ");
LocalDateTime oldDate = LocalDateTime.of(2016, Month.AUGUST, 31, 10, 20, 55);
LocalDateTime newDate = LocalDateTime.of(2016, Month.NOVEMBER, 9, 10, 21, 56);
System.out.println(oldDate);
System.out.println(newDate);
//count seconds between dates
Duration duration = Duration.between(oldDate, newDate);
System.out.println(duration.getSeconds() + " seconds");
}
}
出力
--- Examples --- 3600秒3600秒 --- Duration.between --- 2016-08-31T10:20:55 2016-11-09T10:21:56 6048061 seconds
2.期間の例
2つの
LocalDates`の間で（年、月、日）別々に調べる
java.time.Period`の例
PeriodExample.java
package com.mkyong.time;
import java.time.LocalDate;
import java.time.Month;
import java.time.Period;
public class PeriodExample {
public static void main(String[]args) {
System.out.println("--- Examples --- ");
Period tenDays = Period.ofDays(10);
System.out.println(tenDays.getDays());//10
Period oneYearTwoMonthsThreeDays = Period.of(1, 2, 3);
System.out.println(oneYearTwoMonthsThreeDays.getYears()); //1
System.out.println(oneYearTwoMonthsThreeDays.getMonths()); //2
System.out.println(oneYearTwoMonthsThreeDays.getDays()); //3
System.out.println("\n--- Period.between --- ");
LocalDate oldDate = LocalDate.of(1982, Month.AUGUST, 31);
LocalDate newDate = LocalDate.of(2016, Month.NOVEMBER, 9);
System.out.println(oldDate);
System.out.println(newDate);
//check period between dates
Period period = Period.between(oldDate, newDate);
System.out.print(period.getYears() + " years,");
System.out.print(period.getMonths() + " months,");
System.out.print(period.getDays() + " days");
}
}
出力
--- Examples --- 10 1 2 3 --- Period.between --- 1982-08-31 2016-11-09 34 years,2 months,9 days
3. ChronoUnitの例
あるいは、 `ChronoUnit。{unit} .between`を使って日付の違いを調べることができます。次の例を見てください:
ChronoUnitExample.java
package com.mkyong.time;
import java.time.LocalDateTime;
import java.time.Month;
import java.time.temporal.ChronoUnit;
public class ChronoUnitExample {
public static void main(String[]args) {
LocalDateTime oldDate = LocalDateTime.of(1982, Month.AUGUST, 31, 10, 20, 55);
LocalDateTime newDate = LocalDateTime.of(2016, Month.NOVEMBER, 9, 10, 21, 56);
System.out.println(oldDate);
System.out.println(newDate);
//count between dates
long years = ChronoUnit.YEARS.between(oldDate, newDate);
long months = ChronoUnit.MONTHS.between(oldDate, newDate);
long weeks = ChronoUnit.WEEKS.between(oldDate, newDate);
long days = ChronoUnit.DAYS.between(oldDate, newDate);
long hours = ChronoUnit.HOURS.between(oldDate, newDate);
long minutes = ChronoUnit.MINUTES.between(oldDate, newDate);
long seconds = ChronoUnit.SECONDS.between(oldDate, newDate);
long milis = ChronoUnit.MILLIS.between(oldDate, newDate);
long nano = ChronoUnit.NANOS.between(oldDate, newDate);
System.out.println("\n--- Total --- ");
System.out.println(years + " years");
System.out.println(months + " months");
System.out.println(weeks + " weeks");
System.out.println(days + " days");
System.out.println(hours + " hours");
System.out.println(minutes + " minutes");
System.out.println(seconds + " seconds");
System.out.println(milis + " milis");
System.out.println(nano + " nano");
}
}
出力
1982-08-31T10:20:55 2016-11-09T10:21:56 --- Total --- 34歳 410ヶ月 1784週間 12489日 299736時間 17984161分 1079049661秒 1079049661000ミリス 1079049661000000000ナノ
===参考文献
