Difference Between Two LocalDate in Java

Table of Contents

計算兩個日期差距，提供了幾種方法找到不同時間單位，取得兩者之前的差異，提供了一些常見的方法，例如： Period 、Duration 、 ChronoUnit 、 until 等方式， Calculate Difference Between Two LocalDate 可以計算兩個日期之間的差異，簡化了操作日期比對的方法，本篇增加了範例，並透過單元測試來驗證產出結果。

檔案目錄

./
   +- src
       +- test
       |   +- org
       |       +- ruoxue
       |           +- java_147
       |               +- datetime
       |                   +- localdate
       |                       +- DifferenceTwoLocalDateTest.java

單元測試

Java Time Between Two LocalDate 計算兩個 LocalDate 物件的差異。

Period_between

Java Time Between Two LocalDate 建立兩個 LocalDate ，使用 Period between 靜態方法，可以採用不同的時間單位，計算兩者之間的差異。

	@Test
	public void Period_between() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);
		Period period = Period.between(localDate, localDate2);
		System.out.println(period);

		long years = period.getYears();
		System.out.println(years);
		assertThat(years).isEqualTo(1);

		long months = period.getMonths();
		System.out.println(months);
		assertThat(months).isEqualTo(0);

		long days = period.getDays();
		System.out.println(days);
		assertThat(days).isEqualTo(0);
	}

P1Y
1
0
0

Duration_between

Java Time Between Two LocalDate 建立兩個 LocalDate ，使用 Duration between 靜態方法，可以採用不同的時間單位，計算兩者之間的差異。

	@Test
	public void Duration_between() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);
		Duration duration = Duration.between(localDate.atStartOfDay(), localDate2.atStartOfDay());
		System.out.println(duration);

		long days = duration.toDays();
		System.out.println(days);
		assertThat(days).isEqualTo(366);

		long hours = duration.toHours();
		System.out.println(hours);
		assertThat(hours).isEqualTo(8784);

		long minutes = duration.toMinutes();
		System.out.println(minutes);
		assertThat(minutes).isEqualTo(527040);

		long seconds = duration.getSeconds();
		System.out.println(seconds);
		assertThat(seconds).isEqualTo(31622400);

		long nanos = duration.toNanos();
		System.out.println(nanos);
		assertThat(nanos).isEqualTo(31622400000000000L);
	}

PT8784H
366
8784
527040
31622400
31622400000000000

ChronoUnit_between

Java Time Between Two LocalDate 建立兩個 LocalDate ，使用 ChronoUnit Enum ，可以採用不同的時間單位，計算兩者之間的差異。

	@Test
	public void ChronoUnit_between() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);

		long years = ChronoUnit.YEARS.between(localDate, localDate2);
		System.out.println(years);
		assertThat(years).isEqualTo(1);

		long months = ChronoUnit.MONTHS.between(localDate, localDate2);
		System.out.println(months);
		assertThat(months).isEqualTo(12);

		long weeks = ChronoUnit.WEEKS.between(localDate, localDate2);
		System.out.println(weeks);
		assertThat(weeks).isEqualTo(52);

		long days = ChronoUnit.DAYS.between(localDate, localDate2);
		System.out.println(days);
		assertThat(days).isEqualTo(366);
	}

until

Java Time Between Two LocalDate 建立兩個 LocalDate ，可以採用不同的時間單位，計算兩者之間的差異， Java LocalDate Difference Between Two Dates 提供範例參考。

	@Test
	public void until() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);

		long years = localDate.until(localDate2, ChronoUnit.YEARS);
		System.out.println(years);
		assertThat(years).isEqualTo(1);

		long months = localDate.until(localDate2, ChronoUnit.MONTHS);
		System.out.println(months);
		assertThat(months).isEqualTo(12);

		long weeks = localDate.until(localDate2, ChronoUnit.WEEKS);
		System.out.println(weeks);
		assertThat(weeks).isEqualTo(52);

		long days = localDate.until(localDate2, ChronoUnit.DAYS);
		System.out.println(days);
		assertThat(days).isEqualTo(366);
	}

DifferenceTwoLocalDateTest.java

Difference Between Two LocalDate in Multiple Units 新增單元測試，驗證 Java LocalDate Difference Between Two Dates 是否符合預期。

package org.ruoxue.java_147.datetime.localdate;

import static org.assertj.core.api.Assertions.assertThat;

import java.time.Duration;
import java.time.LocalDate;
import java.time.Period;
import java.time.temporal.ChronoUnit;

import org.junit.Test;

public class DifferenceTwoLocalDateTest {

	@Test
	public void Period_between() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);
		Period period = Period.between(localDate, localDate2);
		System.out.println(period);

		long years = period.getYears();
		System.out.println(years);
		assertThat(years).isEqualTo(1);

		long months = period.getMonths();
		System.out.println(months);
		assertThat(months).isEqualTo(0);

		long days = period.getDays();
		System.out.println(days);
		assertThat(days).isEqualTo(0);
	}

	@Test
	public void Duration_between() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);
		Duration duration = Duration.between(localDate.atStartOfDay(), localDate2.atStartOfDay());
		System.out.println(duration);

		long days = duration.toDays();
		System.out.println(days);
		assertThat(days).isEqualTo(366);

		long hours = duration.toHours();
		System.out.println(hours);
		assertThat(hours).isEqualTo(8784);

		long minutes = duration.toMinutes();
		System.out.println(minutes);
		assertThat(minutes).isEqualTo(527040);

		long seconds = duration.getSeconds();
		System.out.println(seconds);
		assertThat(seconds).isEqualTo(31622400);

		long nanos = duration.toNanos();
		System.out.println(nanos);
		assertThat(nanos).isEqualTo(31622400000000000L);
	}

	@Test
	public void ChronoUnit_between() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);

		long years = ChronoUnit.YEARS.between(localDate, localDate2);
		System.out.println(years);
		assertThat(years).isEqualTo(1);

		long months = ChronoUnit.MONTHS.between(localDate, localDate2);
		System.out.println(months);
		assertThat(months).isEqualTo(12);

		long weeks = ChronoUnit.WEEKS.between(localDate, localDate2);
		System.out.println(weeks);
		assertThat(weeks).isEqualTo(52);

		long days = ChronoUnit.DAYS.between(localDate, localDate2);
		System.out.println(days);
		assertThat(days).isEqualTo(366);
	}

	@Test
	public void until() {
		LocalDate localDate = LocalDate.of(2023, 6, 18);
		LocalDate localDate2 = LocalDate.of(2024, 6, 18);

		long years = localDate.until(localDate2, ChronoUnit.YEARS);
		System.out.println(years);
		assertThat(years).isEqualTo(1);

		long months = localDate.until(localDate2, ChronoUnit.MONTHS);
		System.out.println(months);
		assertThat(months).isEqualTo(12);

		long weeks = localDate.until(localDate2, ChronoUnit.WEEKS);
		System.out.println(weeks);
		assertThat(weeks).isEqualTo(52);

		long days = localDate.until(localDate2, ChronoUnit.DAYS);
		System.out.println(days);
		assertThat(days).isEqualTo(366);
	}
}

心得分享

Java LocalDate Difference Between Two Dates 計算日期，提供不同的時間單位，取得其差異，對日期進行運算更加方便，熟悉 Difference Between Two LocalDate in Multiple Units 這些方法的操作，提升開發效率，在應用上相當廣泛。