import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;

public class LocalTimeDemo {
    public static void main(String[] args) {
        // 1. 獲取當(dāng)前時間
        LocalDate today = LocalDate.now();
        LocalTime nowTime = LocalTime.now();
        LocalDateTime now = LocalDateTime.now();

        // 2. 手動創(chuàng)建時間
        LocalDate birthDay = LocalDate.of(2000, 1, 1);
        LocalDateTime meeting = LocalDateTime.of(2025, 12, 25, 14, 30);

        // 3. 常用操作：加減時間（不可變，返回新對象）
        LocalDate nextWeek = today.plusWeeks(1);
        LocalDateTime beforeHour = now.minusHours(1);

        System.out.println("當(dāng)前日期：" + today);
        System.out.println("會議時間：" + meeting);
    }
}

import java.time.OffsetDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;

public class ZoneTimeDemo {
    public static void main(String[] args) {
        // 1. 當(dāng)前帶偏移量的時間
        OffsetDateTime offsetNow = OffsetDateTime.now();

        // 2. 指定時區(qū)創(chuàng)建時間
        ZonedDateTime shanghaiTime = ZonedDateTime.now(ZoneId.of("Asia/Shanghai"));
        ZonedDateTime newYorkTime = ZonedDateTime.now(ZoneId.of("America/New_York"));

        System.out.println("上海時間：" + shanghaiTime);
        System.out.println("紐約時間：" + newYorkTime);
    }
}

import java.time.Instant;

public class InstantDemo {
    public static void main(String[] args) {
        // 1. 獲取當(dāng)前時間戳
        Instant now = Instant.now();

        // 2. 時間戳轉(zhuǎn)秒/毫秒（兼容舊系統(tǒng)）
        long second = now.getEpochSecond();
        long milli = now.toEpochMilli();

        // 3. 手動創(chuàng)建
        Instant instant = Instant.ofEpochMilli(System.currentTimeMillis());

        System.out.println("當(dāng)前UTC時間：" + now);
        System.out.println("時間戳（毫秒）：" + milli);
    }
}

import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.Period;

public class TimeGapDemo {
    public static void main(String[] args) {
        // 1. 計算日期間隔（生日天數(shù)）
        LocalDate today = LocalDate.now();
        LocalDate birthDay = LocalDate.of(2000, 1, 1);
        Period period = Period.between(birthDay, today);
        System.out.println("年齡：" + period.getYears() + "歲");

        // 2. 計算時間間隔（會議時長）
        LocalDateTime start = LocalDateTime.of(2025, 12, 25, 14, 0);
        LocalDateTime end = LocalDateTime.of(2025, 12, 25, 16, 30);
        Duration duration = Duration.between(start, end);
        System.out.println("會議時長：" + duration.toHours() + "小時");
    }
}

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class FormatDemo {
    public static void main(String[] args) {
        // 定義格式化器
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        LocalDateTime now = LocalDateTime.now();

        // 時間 → 字符串
        String formatTime = now.format(formatter);

        // 字符串 → 時間
        LocalDateTime parseTime = LocalDateTime.parse("2025-12-25 14:30:00", formatter);

        System.out.println("格式化后：" + formatTime);
    }
}

// LocalDateTime → Instant（帶時區(qū)）
LocalDateTime local = LocalDateTime.now();
Instant instant = local.atZone(ZoneId.systemDefault()).toInstant();

// Instant → LocalDateTime
LocalDateTime localTime = LocalDateTime.ofInstant(instant, ZoneId.systemDefault());