Java 中带有 DayOfMonth()方法的 LocalDateTime,示例

原文:https://www . geeksforgeeks . org/local datetime-with dayofmonth-in-Java-method-with-examples/

Java 中 LocalDateTime 类withDayOfMonth() 方法用于获取该 LocalDateTime 的副本,DayOfMonth 更改为 dayOfMonth 作为参数传递给该方法。该本地日期时间的其余值保持不变。

语法:

public LocalDateTime withDayOfMonth(int dayOfMonth)

参数:此方法接受单个强制参数日期月,该参数指定了要在结果 LocalDateTime 实例中设置的日期月。这个日期的值可以从 1 到 31。

返回:该函数返回一个本地日期时间实例,将日期月更改为日期月作为参数传递给该方法。该本地日期时间的其余值保持不变。

异常:如果第几个月的值无效,函数会抛出日期时间异常

下面的程序说明了 LocalDateTime.withDayOfMonth()方法:

程序 1:

// Program to illustrate the withDayOfMonth() method

import java.util.*;
import java.time.*;

public class GfG {
    public static void main(String[] args)
    {
        // Get the LocalDateTime instance
        LocalDateTime dt = LocalDateTime.now();

        // Get the String representation of this LocalDateTime
        System.out.println("Original LocalDateTime: "
                           + dt.toString());

        // Get a new LocalDateTime with dayOfMonth 25
        System.out.println("New LocalDateTime: "
                           + dt.withDayOfMonth(25));
    }
}

输出:

Original LocalDateTime: 2018-11-30T10:38:27.429
New LocalDateTime: 2018-11-25T10:38:27.429

程序二:

// Program to illustrate the withDayOfMonth() method

import java.util.*;
import java.time.*;

public class GfG {
    public static void main(String[] args)
    {
        // Get the LocalDateTime instance
        LocalDateTime dt
            = LocalDateTime
                  .parse("2015-04-06T10:15:30");

        // Get the String representation of this LocalDateTime
        System.out.println("Original LocalDateTime: "
                           + dt.toString());

        // Get a new LocalDateTime with dayOfMonth 1
        System.out.println("New LocalDateTime: "
                           + dt.withDayOfMonth(1));
    }
}

输出:

Original LocalDateTime: 2015-04-06T10:15:30
New LocalDateTime: 2015-04-01T10:15:30

参考:T2【https://docs . Oracle . com/javase/10/docs/API/Java/time/local datetime . html # with dayofmonth(int)