Table of Contents

Initialize LocalTime in Java

初始化 LocalTime 物件的值不會被改變，可以同時在不同的執行緒下被使用，介紹常見的 of 、 parse 、 ofSecondOfDay 等方法，了解 Initialize LocalTime Java 的不同操作和方法，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
       |                   +- localtime
       |                       +- InitializeLocalTimeTest.java

單元測試

Java Initialize LocalTime 提供初始化操作 LocalTime 。

now

Java Initialize LocalTime 建立一個 LocalTime ，提供目前時間。

	@Test
	public void now() {
		LocalTime localTime = LocalTime.now();
		System.out.println(localTime);

		ZoneId zone = ZoneId.of("Europe/London");
		localTime = LocalTime.now(zone);
		System.out.println(localTime);

		zone = ZoneId.of("UTC+1");
		Clock clock = Clock.system(zone);
		localTime = LocalTime.now(clock);
		System.out.println(localTime);

		zone = ZoneId.of("Etc/GMT-1");
		localTime = LocalTime.now(zone);
		System.out.println(localTime);
	}

21:03:22.559
14:03:22.561
14:03:22.566
14:03:22.566

of

Java Initialize LocalTime 建立一個 LocalTime ，建立指定時間。

	@Test
	public void of() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());

		int secondOfDay = localTime.toSecondOfDay();
		System.out.println(secondOfDay);
		assertEquals(33125L, secondOfDay);

		localTime = LocalTime.of(9, 12, 6, 123456789);
		System.out.println(localTime);
		assertEquals("09:12:06.123456789", localTime.toString());

		localTime = LocalTime.ofSecondOfDay(33127L);
		System.out.println(localTime);
		assertEquals("09:12:07", localTime.toString());
	}

09:12:05
33125
09:12:06.123456789
09:12:07

parse

Java Initialize LocalTime 建立一個 LocalTime ，建立指定時間。

	@Test
	public void parse() {
		LocalTime localTime = LocalTime.parse("09:12:05");
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());

		localTime = LocalTime.parse("091205", DateTimeFormatter.ofPattern("HHmmss"));
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());

		localTime = LocalTime.parse("09-12-05.123", DateTimeFormatter.ofPattern("HH-mm-ss.SSS"));
		System.out.println(localTime);
		assertEquals("09:12:05.123", localTime.toString());
	}

09:12:05
09:12:05
09:12:05.123

from

LocalTime Initialization Java 建立一個 LocalTime ，從另一個時間，建立指定時間。

	@Test
	public void from() {
		LocalTime localTime = LocalTime.parse("09:12:05.123456789");
		LocalTime result = LocalTime.from(localTime);
		System.out.println(result);
		assertEquals("09:12:05.123456789", result.toString());

		localTime = LocalTime.parse("09:12:05.123");
		ZoneOffset zoneOffset = ZoneOffset.of("+01:00");
		OffsetTime offsetTime = OffsetTime.of(localTime, zoneOffset);
		System.out.println(offsetTime);
		result = LocalTime.from(offsetTime);
		System.out.println(result);
		assertEquals("09:12:05.123", result.toString());

		ZonedDateTime zonedDateTime = ZonedDateTime.parse("2023-12-25T09:12:05+01:00[Europe/London]");
		result = LocalTime.from(zonedDateTime);
		System.out.println(result);
		assertEquals("09:12:05", result.toString());
	}

09:12:05.123456789
09:12:05.123+01:00
09:12:05.123
09:12:05

ofSecondOfDay

LocalTime Initialization Java 建立一個 LocalTime ，將本日秒轉成指定時間。

	@Test
	public void ofSecondOfDay() {
		LocalTime localTime = LocalTime.ofSecondOfDay(33125L);
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());
	}

09:12:05

ofNanoOfDay

LocalTime Initialization Java 建立一個 LocalTime ，將本日奈秒轉成指定時間。

	@Test
	public void ofNanoOfDay() {
		LocalTime localTime = LocalTime.ofNanoOfDay(33125123456789L);
		System.out.println(localTime);
		assertEquals("09:12:05.123456789", localTime.toString());
	}

09:12:05.123456789

InitializeLocalTimeTest.java

LocalTime Initialization Java 新增單元測試，驗證 Java LocalTime Initialize 是否符合預期。

package org.ruoxue.java_147.datetime.localtime;

import static org.junit.Assert.*;

import java.time.Clock;
import java.time.LocalTime;
import java.time.OffsetTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

import org.junit.Test;

public class InitializeLocalTimeTest {

	@Test
	public void now() {
		LocalTime localTime = LocalTime.now();
		System.out.println(localTime);

		ZoneId zone = ZoneId.of("Europe/London");
		localTime = LocalTime.now(zone);
		System.out.println(localTime);

		zone = ZoneId.of("UTC+1");
		Clock clock = Clock.system(zone);
		localTime = LocalTime.now(clock);
		System.out.println(localTime);

		zone = ZoneId.of("Etc/GMT-1");
		localTime = LocalTime.now(zone);
		System.out.println(localTime);
	}

	@Test
	public void of() {
		LocalTime localTime = LocalTime.of(9, 12, 5);
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());

		int secondOfDay = localTime.toSecondOfDay();
		System.out.println(secondOfDay);
		assertEquals(33125L, secondOfDay);

		localTime = LocalTime.of(9, 12, 6, 123456789);
		System.out.println(localTime);
		assertEquals("09:12:06.123456789", localTime.toString());

		localTime = LocalTime.ofSecondOfDay(33127L);
		System.out.println(localTime);
		assertEquals("09:12:07", localTime.toString());
	}

	@Test
	public void parse() {
		LocalTime localTime = LocalTime.parse("09:12:05");
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());

		localTime = LocalTime.parse("091205", DateTimeFormatter.ofPattern("HHmmss"));
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());

		localTime = LocalTime.parse("09-12-05.123", DateTimeFormatter.ofPattern("HH-mm-ss.SSS"));
		System.out.println(localTime);
		assertEquals("09:12:05.123", localTime.toString());
	}

	@Test
	public void from() {
		LocalTime localTime = LocalTime.parse("09:12:05.123456789");
		LocalTime result = LocalTime.from(localTime);
		System.out.println(result);
		assertEquals("09:12:05.123456789", result.toString());

		localTime = LocalTime.parse("09:12:05.123");
		ZoneOffset zoneOffset = ZoneOffset.of("+01:00");
		OffsetTime offsetTime = OffsetTime.of(localTime, zoneOffset);
		System.out.println(offsetTime);
		result = LocalTime.from(offsetTime);
		System.out.println(result);
		assertEquals("09:12:05.123", result.toString());

		ZonedDateTime zonedDateTime = ZonedDateTime.parse("2023-12-25T09:12:05+01:00[Europe/London]");
		result = LocalTime.from(zonedDateTime);
		System.out.println(result);
		assertEquals("09:12:05", result.toString());
	}

	@Test
	public void ofSecondOfDay() {
		LocalTime localTime = LocalTime.ofSecondOfDay(33125L);
		System.out.println(localTime);
		assertEquals("09:12:05", localTime.toString());
	}

	@Test
	public void ofNanoOfDay() {
		LocalTime localTime = LocalTime.ofNanoOfDay(33125123456789L);
		System.out.println(localTime);
		assertEquals("09:12:05.123456789", localTime.toString());
	}
}