Compare LocalTimes in Java

Table of Contents

提供幾個操作方法，像是： compareTo 、 isBefore 、 isAfter 等方法，比較時間與另一個時間，檢查前後或相等的時間， Java Compare LocalTimes 屬於 java.time 套件，時間和時間相關的 API ，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
       |                   +- localtime
       |                       +- CompareLocalTimesTest.java

單元測試

Compare LocalTime Instances 提供比較兩個 LocalTime 物件的方法。

compareTo

Compare LocalTime Instances 建立兩個 LocalTime ，比較時間物件，根據比較結果傳回一個整數值，不考慮時區或日曆資訊。

指定的時間早於另一個時間，則為負整數，如： a 小於 b 傳回 -1 。
指定的時間等於另一個時間，則為零，如： a 等於 b 傳回 0 。
指定的時間晚於另一個時間，則為正整數，如： a 大於 b 傳回 1 。

	@Test
	public void compareTo() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(10, 12, 5);
		int result = localTime.compareTo(localTime2);
		System.out.println(result);
		assertThat(result).isLessThan(0);

		localTime = LocalTime.of(9, 12, 5);
		localTime2 = LocalTime.of(9, 12, 5);
		result = localTime.compareTo(localTime2);
		System.out.println(result);
		assertThat(result).isEqualTo(0);

		localTime = LocalTime.of(9, 12, 5);
		localTime2 = LocalTime.of(8, 12, 5);
		result = localTime.compareTo(localTime2);
		System.out.println(result);
		assertThat(result).isGreaterThan(0);
	}

-1
0
1

isBefore

Compare LocalTime Instances 建立兩個 LocalTime ，檢查指定的時間是否早於另一個時間。

	@Test
	public void isBefore() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(10, 12, 5);
		boolean result = localTime.isBefore(localTime2);
		System.out.println(result);
		assertThat(result).isTrue();

		result = localTime2.isBefore(localTime);
		System.out.println(result);
		assertThat(result).isFalse();
	}

true
false

isAfter

Compare LocalTime Instances 建立兩個 LocalTime ，檢查指定的時間是否晚於另一個時間。

	@Test
	public void isAfter() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(8, 12, 5);
		boolean result = localTime.isAfter(localTime2);
		System.out.println(result);
		assertThat(result).isTrue();

		result = localTime2.isAfter(localTime);
		System.out.println(result);
		assertThat(result).isFalse();
	}

true
false

equals

Compare Two LocalTime Instances 建立兩個 LocalTime ，檢查指定的時間是否等於另一個時間。

	@Test
	public void equals() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(9, 12, 5);
		boolean result = localTime.equals(localTime2);
		System.out.println(result);
		assertThat(result).isTrue();

		result = localTime2.equals(localTime);
		System.out.println(result);
		assertThat(result).isTrue();
	}

true
false

CompareLocalTimesTest.java

Compare Two LocalTime Instances 新增單元測試，驗證是否符合預期。

package org.ruoxue.java_147.datetime.localtime;

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

import java.time.LocalTime;

import org.junit.Test;

public class CompareLocalTimesTest {

	@Test
	public void compareTo() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(10, 12, 5);
		int result = localTime.compareTo(localTime2);
		System.out.println(result);
		assertThat(result).isLessThan(0);

		localTime = LocalTime.of(9, 12, 5);
		localTime2 = LocalTime.of(9, 12, 5);
		result = localTime.compareTo(localTime2);
		System.out.println(result);
		assertThat(result).isEqualTo(0);

		localTime = LocalTime.of(9, 12, 5);
		localTime2 = LocalTime.of(8, 12, 5);
		result = localTime.compareTo(localTime2);
		System.out.println(result);
		assertThat(result).isGreaterThan(0);
	}

	@Test
	public void isBefore() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(10, 12, 5);
		boolean result = localTime.isBefore(localTime2);
		System.out.println(result);
		assertThat(result).isTrue();

		result = localTime2.isBefore(localTime);
		System.out.println(result);
		assertThat(result).isFalse();
	}

	@Test
	public void isAfter() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(8, 12, 5);
		boolean result = localTime.isAfter(localTime2);
		System.out.println(result);
		assertThat(result).isTrue();

		result = localTime2.isAfter(localTime);
		System.out.println(result);
		assertThat(result).isFalse();
	}

	@Test
	public void equals() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		LocalTime localTime2 = LocalTime.of(9, 12, 5);
		boolean result = localTime.equals(localTime2);
		System.out.println(result);
		assertThat(result).isTrue();

		result = localTime2.equals(localTime);
		System.out.println(result);
		assertThat(result).isTrue();
	}
}