Java Calendar computeFields()用法及代码示例

Calendar类中的computeFields()方法用于将当前毫秒时间值time转换为field []中提到的日历字段值。

注意：这允许将为日历对象设置的新时间与日历字段值同步。

用法:

protected abstract void computeFields()

参数：该方法不带任何参数。

返回值：该方法不返回任何值。

以下示例程序旨在说明Calendar类的computeFields()方法的用法：
示例1:

// Java Code to illustrate 
// computeFields() Method 
  
import java.util.*; 
  
public class CalendarClassDemo 
    extends GregorianCalendar { 
    public static void main(String args[]) 
    { 
        // Creating calendar object 
        CalendarClassDemo calndr = new CalendarClassDemo(); 
  
        // Displaying the current date 
        System.out.println("The Current "
                           + "date is: " + calndr.getTime()); 
  
        // Clearing the calendar 
        calndr.clear(); 
  
        // Set a new year and call 
        // computeFields() 
        calndr.set(GregorianCalendar.YEAR, 2016); 
        calndr.computeFields(); 
  
        // Displaying the current date 
        System.out.println("The recent"
                           + " date is: " + calndr.getTime()); 
    } 
}

输出：

The Current date is: Wed Feb 13 16:15:15 UTC 2019
The recent date is: Wed Feb 13 16:15:15 UTC 2019

示例2:

// Java Code to illustrate 
// computeFields() Method 
  
import java.util.*; 
  
public class CalendarClassDemo 
    extends GregorianCalendar { 
    public static void main(String args[]) 
    { 
        // Creating calendar object 
        CalendarClassDemo calndr = new CalendarClassDemo(); 
  
        // Displaying the current date 
        System.out.println("The Current "
                           + "date is: " + calndr.getTime()); 
  
        // Clearing the calendar 
        calndr.clear(); 
  
        // Set a new year and call 
        // computeFields() 
        calndr.set(GregorianCalendar.YEAR, 2000); 
        calndr.computeFields(); 
  
        // Displaying the current date 
        System.out.println("The recent"
                           + " date is: " + calndr.getTime()); 
    } 
}

输出：

The Current date is: Wed Feb 13 16:15:18 UTC 2019
The recent date is: Wed Feb 13 16:15:18 UTC 2019

参考： https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html#computeFields()

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注：本文由纯净天空筛选整理自Chinmoy Lenka大神的英文原创作品 Calendar computeFields() method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。