Java中的 MonthDay withDayOfMonth() 方法及示例

用于更改 MonthDay 对象的月份日期的MonthDay类的withDayOfMonth(int dayOfMonth)方法，使用作为参数传递的 dayOfMonth 并在该方法之后返回更改后的 MonthDay 的副本。如果是月份的日期，则会引发异常变更操作后指定月份的值无效。

句法：

public MonthDay withDayOfMonth(int dayOfMonth)

参数：此方法接受dayOfMonth作为参数，这是要在返回月日中设置的月日，从 1 到 31。

返回值：此方法根据请求日的本月日返回一个 MonthDay。

异常：如果月份的日期值无效，或者月份的日期对月份无效，则此方法将引发DateTimeException 。

下面的程序说明了 withDayOfMonth() 方法：
方案一：

// Java program to demonstrate
// MonthDay.withDayOfMonth() method
  
import java.time.*;
import java.time.temporal.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a MonthDay object
        MonthDay monthday
            = MonthDay.of(8, 28);
  
        // print instance
        System.out.println("MonthDay before"
                           + " applying method: "
                           + monthday);
  
        // apply withDayOfMonth method
        // of MonthDay class
        MonthDay updatedlocal
            = monthday.withDayOfMonth(21);
  
        // print instance
        System.out.println("MonthDay after"
                           + " applying method: "
                           + updatedlocal);
    }
}

输出：

MonthDay before applying method: --08-28
MonthDay after applying method: --08-21

方案二：

// Java program to demonstrate
// MonthDay.withDayOfMonth() method
  
import java.time.*;
import java.time.temporal.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a MonthDay object
        MonthDay monthday
            = MonthDay.of(10, 31);
  
        // print instance
        System.out.println("MonthDay before"
                           + " applying method: "
                           + monthday);
  
        // apply withDayOfMonth method
        // of MonthDay class
        MonthDay updatedlocal
            = monthday.withDayOfMonth(12);
  
        // print instance
        System.out.println("MonthDay after"
                           + " applying method: "
                           + updatedlocal);
    }
}

输出：

MonthDay before applying method: --10-31
MonthDay after applying method: --10-12

参考资料： https: Java/time/MonthDay.html#withDayOfMonth(int)