java日历类add方法

日历类的computeFields()方法 (Calendar Class computeFields() method)

• computeFields() method is available in java.util package.

  在java.util包中提供了validateFields()方法 。

• computeFields() method is used to convert current ms(milliseconds) time value time to calendar field values in fields.

  computeFields()方法用于将当前ms(毫秒)时间值time转换为字段中的日历字段值。

• computeFields() method is a non-static method, it is accessible with the class object and if we try to access these methods with the class name then we will get an error.

  computeFields()方法是一种非静态方法，可通过类对象访问，如果尝试使用类名访问这些方法，则会收到错误消息。

• computeFields() method does not throw an exception at the time of computing Calendar fields.

  在计算Calendar字段时， computeFields()方法不会引发异常。

Syntax:

句法：

    protected void computeFields();

Parameter(s):

参数：

• It does not accept any parameter.

  它不接受任何参数。

Return value:

返回值：

The return type of the method is void, it returns nothing.

该方法的返回类型为void ，不返回任何内容。

Example:

例：

// Java Program to demonstrate the example of
// void computeFields() method of Calendar
import java.util.*;
public class ComputeFieldOfCalendar extends GregorianCalendar {
public static void main(String[] args) {
// Instantiating a Calendar object
ComputeFieldOfCalendar ca = new ComputeFieldOfCalendar();
// Display current calendar
System.out.println("ca: " + ca.getTime());
// By using clear(int fi) method to set the field unset
ca.clear(GregorianCalendar.MONTH);
// Display calendar
System.out.println("ca.clear(GregorianCalendar.MONTH): " + ca.getTime());
// By using set() method is to set a month 
// and invoke computeFields()
ca.set(GregorianCalendar.MONTH, 6);
ca.computeFields();
// Display calendar
System.out.println("ca.set(GregorianCalendar.MONTH,6): " + ca.getTime());
}
}

Output

输出量

ca: Fri Jan 24 12:24:23 GMT 2020
ca.clear(GregorianCalendar.MONTH): Fri Jan 24 12:24:23 GMT 2020
ca.set(GregorianCalendar.MONTH,6): Fri Jan 24 12:24:23 GMT 2020

翻译自: https://www.includehelp.com/java/calendar-computefields-method-with-example.aspx

java日历类add方法