Java时间差计算：告别Date类陷阱，拥抱现代java.time API

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;
import org.apache.commons.lang3.time.DurationFormatUtils; // 假设已引入此库

public class TimeCalculatorLegacy {

    private String loginTime;
    private String breakTime;
    private String logoutTime;

    public String calculateHoursWorked() throws ParseException {
        Scanner sc = new Scanner(System.in);
        System.out.println("Please enter your login time:");
        loginTime = sc.nextLine();
        System.out.println("Please enter your break duration:");
        breakTime = sc.nextLine();
        System.out.println("Please enter your logout time:");
        logoutTime = sc.nextLine();

        SimpleDateFormat format = new SimpleDateFormat("HH:mm");
        Date login = format.parse(loginTime);
        Date logout = format.parse(logoutTime);
        Date breakPeriod = format.parse(breakTime); // 将休息时长解析为Date对象

        // 计算总工作毫秒数
        long totalHoursWorked = logout.getTime() - login.getTime() - breakPeriod.getTime();

        // 验证休息时长
        long breakTimeinMilliseconds = breakPeriod.getTime();
        System.out.println("So our break time in ms is: " + breakTimeinMilliseconds);
        String test = DurationFormatUtils.formatDuration(breakTimeinMilliseconds, "HH:mm");
        System.out.println("Your break time is: " + test);

        return DurationFormatUtils.formatDuration(totalHoursWorked, "HH:mm");
    }

    public static void main(String[] args) throws ParseException {
        TimeCalculatorLegacy calculator = new TimeCalculatorLegacy();
        System.out.println("Your working time is: " + calculator.calculateHoursWorked());
    }
}

So our break time in ms is: 3600000
Your break time is: 01:00 (预期是02:00，但显示01:00)
Your working time is: 07:00 (预期是6:00，但显示07:00)

import java.time.Duration;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.Scanner;

public class TimeCalculatorModern {

    public String calculateHoursWorked() {
        Scanner sc = new Scanner(System.in);
        System.out.println("Please enter your login time (HH:mm):");
        String loginTimeStr = sc.nextLine();
        System.out.println("Please enter your break duration (HH:mm):");
        String breakDurationStr = sc.nextLine(); // 注意这里是duration
        System.out.println("Please enter your logout time (HH:mm):");
        String logoutTimeStr = sc.nextLine();
        sc.close(); // 关闭Scanner

        // 使用LocalTime解析登录和登出时间点
        LocalTime loginTime = LocalTime.parse(loginTimeStr);
        LocalTime logoutTime = LocalTime.parse(logoutTimeStr);

        // 解析休息时长。由于LocalTime.parse("HH:mm")会将其视为一天中的某个时间点，
        // 为了将其转换为Duration，我们可以计算它与午夜的差值。
        LocalTime breakTimePoint = LocalTime.parse(breakDurationStr);
        Duration breakDuration = Duration.between(LocalTime.MIDNIGHT, breakTimePoint);

        // 计算总工作时长
        // Duration.between(start, end) 计算两个时间点之间的持续时间
        Duration workDuration = Duration.between(loginTime, logoutTime);

        // 减去休息时长
        Duration totalWorkDuration = workDuration.minus(breakDuration);

        // 格式化输出结果
        // Duration本身没有直接的HH:mm格式化方法，可以通过将其加到午夜时间点再格式化
        // 或者使用自定义的格式化逻辑。这里采用加到午夜时间点的方式。
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm");
        String formattedBreakDuration = LocalTime.MIDNIGHT.plus(breakDuration).format(formatter);
        String formattedTotalWorkDuration = LocalTime.MIDNIGHT.plus(totalWorkDuration).format(formatter);

        System.out.println("Your break duration is: " + formattedBreakDuration);
        return formattedTotalWorkDuration;
    }

    public static void main(String[] args) {
        TimeCalculatorModern calculator = new TimeCalculatorModern();
        System.out.println("Your working time is: " + calculator.calculateHoursWorked());
    }
}

Your break duration is: 02:00
Your working time is: 06:00