Java Calendar類工作日計算的代碼復用與模塊化

要實現工作日計算的代碼復用與模塊化，可以將代碼封裝成一個單獨的工具類，供其他類調用。以下是一個示例代碼：

工作日計算工具類：

import java.util.Calendar;

public class WorkdayCalculator {

    public static int calculateWorkdays(Calendar startDate, Calendar endDate) {
        int workdays = 0;
        
        while (startDate.before(endDate) || startDate.equals(endDate)) {
            if (startDate.get(Calendar.DAY_OF_WEEK) != Calendar.SATURDAY && startDate.get(Calendar.DAY_OF_WEEK) != Calendar.SUNDAY) {
                workdays++;
            }
            startDate.add(Calendar.DAY_OF_MONTH, 1);
        }
        
        return workdays;
    }
}

在其他類中調用工作日計算工具類：

import java.util.Calendar;

public class Main {

    public static void main(String[] args) {
        Calendar startDate = Calendar.getInstance();
        startDate.set(2022, Calendar.JANUARY, 1);
        
        Calendar endDate = Calendar.getInstance();
        endDate.set(2022, Calendar.JANUARY, 31);
        
        int workdays = WorkdayCalculator.calculateWorkdays(startDate, endDate);
        System.out.println("Workdays between " + startDate.getTime() + " and " + endDate.getTime() + ": " + workdays);
    }
}

通過將工作日計算邏輯封裝在一個單獨的工具類中，可以實現代碼的復用和模塊化，提高代碼的可維護性和可讀性。其他類只需調用工作日計算工具類的方法即可完成工作日計算，而無需重復編寫計算邏輯。