Java 8 – TemporalAdjusters示例

小咪咪 2023-02-15 05:17 9阅读 0赞

在Java 8中，可以使用预定义的`java.time.temporal.TemporalAdjusters`来调整日期或[Temporal][]

## 1.时间调整器 ##

将日期移动到firstDayOfMonth，firstDayOfNextMonth，下周一等的示例。

TestDate.java

package com.mkyong.time;
    
    import java.time.DayOfWeek;
    import java.time.LocalDate;
    import java.time.temporal.TemporalAdjusters;
    
    public class TestDate {
    
        public static void main(String[] args) {
    
            LocalDate localDate = LocalDate.now();
            System.out.println("current date : " + localDate);
    
            LocalDate with = localDate.with(TemporalAdjusters.firstDayOfMonth());
            System.out.println("firstDayOfMonth : " + with);
    
            LocalDate with1 = localDate.with(TemporalAdjusters.lastDayOfMonth());
            System.out.println("lastDayOfMonth : " + with1);
    
            LocalDate with2 = localDate.with(TemporalAdjusters.next(DayOfWeek.MONDAY));
            System.out.println("next monday : " + with2);
    
            LocalDate with3 = localDate.with(TemporalAdjusters.firstDayOfNextMonth());
            System.out.println("firstDayOfNextMonth : " + with3);
    
        }
    
    }

输出量

current date : 2016-11-15
    firstDayOfMonth : 2016-11-01
    lastDayOfMonth : 2016-11-30
    next monday : 2016-11-21
    firstDayOfNextMonth : 2016-12-01

> **注意**  
> 请检查此[官方TemporalAdjusters JavaDoc][TemporalAdjusters JavaDoc] ，以获取预定义的TemporalAdjusters的完整列表。

## 2.自定义TemporalAdjuster ##

实现`TemporalAdjuster`将日期移动到下一个圣诞节的示例。

NextChristmas.java

package com.mkyong.time;
    
    import java.time.temporal.ChronoField;
    import java.time.temporal.Temporal;
    import java.time.temporal.TemporalAdjuster;
    
    public class NextChristmas implements TemporalAdjuster {
    
        @Override
        public Temporal adjustInto(Temporal temporal) {
    
            return temporal.with(ChronoField.MONTH_OF_YEAR, 12).with(ChronoField.DAY_OF_MONTH, 25);
    
        }
    }

TestDate.java

package com.mkyong.time;
    
    import java.time.LocalDate;
    
    public class TestDate {
    
        public static void main(String[] args) {
    
            LocalDate localDate = LocalDate.now();
            System.out.println("current date : " + localDate);
    
            localDate = localDate.with(new NextChristmas());
            System.out.println("Next Christmas : " + localDate);
    
        }
    
    }

输出量

current date : 2016-11-15
    Next Christmas : 2016-12-25

另外，您可以使用以下lambda表达式：

localDate = localDate.with(
    		temporal -> temporal.with(ChronoField.MONTH_OF_YEAR, 12).with(ChronoField.DAY_OF_MONTH, 25)
    	);

## 参考文献 ##

1.  [Java 8 – HijrahDate，如何计算斋月日期][Java 8 _ HijrahDate]
2.  [TemporalAdjuster JavaDoc][]
3.  [TemporalAdjusters JavaDoc][]
4.  [时态JavaDoc][Temporal]
5.  [维基百科圣诞节][Link 1]

标签： [日期][Link 2] [java.time][] [java8][] [TemporalAdjusters][]

> 翻译自: [https://mkyong.com/java8/java-8-temporaladjusters-examples/][https_mkyong.com_java8_java-8-temporaladjusters-examples]

[Temporal]: https://docs.oracle.com/javase/8/docs/api/java/time/temporal/Temporal.html
[TemporalAdjusters JavaDoc]: https://docs.oracle.com/javase/8/docs/api/java/time/temporal/TemporalAdjusters.html
[Java 8 _ HijrahDate]: http://www.mkyong.com/java8/java-8-hijrahdate-how-to-calculate-the-ramadan-date/
[TemporalAdjuster JavaDoc]: https://docs.oracle.com/javase/8/docs/api/java/time/temporal/TemporalAdjuster.html
[Link 1]: https://en.wikipedia.org/wiki/Christmas
[Link 2]: https://mkyong.com/tag/date/
[java.time]: https://mkyong.com/tag/java-time/
[java8]: https://mkyong.com/tag/java8/
[TemporalAdjusters]: https://mkyong.com/tag/temporaladjusters/
[https_mkyong.com_java8_java-8-temporaladjusters-examples]: https://mkyong.com/java8/java-8-temporaladjusters-examples/