公曆日曆方法

Question

我試圖創建一個程序，它將兩個日期作爲參數，並返回日期是否在當前周內，但我在isDateInCurrentWeek的調用中遇到問題。當我嘗試編譯程序時，收到錯誤消息，說

requestHoliday.java:16: isDateInCurrentWeek(java.util.GregorianCalendar) in requestHoliday cannot be applied to (java.util.Calendar) 
     if (isDateInCurrentWeek(startDate) && isDateInCurrentWeek(endDate)); 

。

import java.util.*; 
import java.text.*; 

public class hols { 
    public static void main(String[] args) { 
     DateFormat df = new SimpleDateFormat("dd MM yyyy"); 
     Date start = df.parse(args[0]); 
     Date end = df.parse(args[1]); 
     Calendar startDate = new GregorianCalendar(); 
     Calendar endDate = new GregorianCalendar(); 
     startDate.setTime(start); 
     endDate.setTime(end); 
     if(isDateInCurrentWeek(startDate) && isDateInCurrentWeek(endDate)); 
     System.out.println("Date is in current week!"); 
    } 

    public static boolean isDateInCurrentWeek(GregorianCalendar date) { 
     Calendar currentCalendar = GregorianCalendar.getInstance(); 
     int week = currentCalendar.get(Calendar.WEEK_OF_YEAR); 
     int year = currentCalendar.get(Calendar.YEAR); 
     Calendar targetCalendar = GregorianCalendar.getInstance(); 
     targetCalendar = date; 
     int targetWeek = targetCalendar.get(Calendar.WEEK_OF_YEAR); 
     int targetYear = targetCalendar.get(Calendar.YEAR); 
     return week == targetWeek && year == targetYear; 
    } 
} 

不太清楚是什麼問題，因爲該方法需要一個GregorianCalendar作爲輸入，兩個日期都在陽曆的格式。有人知道嗎？

Answer 1

您在if年底有;，刪除它...

公曆日曆，而不是相反。 如果抽象和通用方法適合您的需要，請更改簽名以使用日曆。在可能的情況下，最好使用契約，而不是在What does it mean to "program to an interface"?中解釋的實現（感謝Luiggi）。

hols id不是good class name。 Hols可能會更好......

此代碼工作得很好：

import java.text.DateFormat; 
import java.text.ParseException; 
import java.text.SimpleDateFormat; 
import java.util.Calendar; 
import java.util.Date; 
import java.util.GregorianCalendar; 

public class Hols { 
    public static void main(String[] args) throws ParseException { 
     DateFormat df = new SimpleDateFormat("dd MM yyyy"); 
     Date start = df.parse(args[0]); 
     Date end = df.parse(args[1]); 
     Calendar startDate = new GregorianCalendar(); 
     Calendar endDate = new GregorianCalendar(); 
     startDate.setTime(start); 
     endDate.setTime(end); 
     if(isDateInCurrentWeek(startDate) && isDateInCurrentWeek(endDate)) 
     System.out.println("Date is in current week!"); 
     else 
     System.out.println("Date is NOT in current week!"); 
    } 

    public static boolean isDateInCurrentWeek(Calendar date) { 
     Calendar currentCalendar = Calendar.getInstance(); 
     int week = currentCalendar.get(Calendar.WEEK_OF_YEAR); 
     int year = currentCalendar.get(Calendar.YEAR); 
     Calendar targetCalendar = Calendar.getInstance(); 
     targetCalendar = date; 
     int targetWeek = targetCalendar.get(Calendar.WEEK_OF_YEAR); 
     int targetYear = targetCalendar.get(Calendar.YEAR); 
     return week == targetWeek && year == targetYear; 
    } 
} 

Answer 2

當您撥打isDateInCurrentWeek時，您傳入的變量鍵入Calendar。改爲將其聲明爲GregorianCalendar。

或者如果您不需要任何東西GregorianCalendar特定，請更改方法簽名，如果isDateInCurrentWeek接受Calendar。