Java 日历 computeTime()方法及示例

Calendar类中的 computeTime() 方法用于将字段[]中的当前日历字段值转换为毫秒级时间值的操作。

语法

protected abstract void computeTime()

参数： 该方法不接受任何参数。

返回值： 该方法不返回任何值。

下面的程序说明了日历类的computeTime()方法的工作原理：

例1 :

// Java Code to illustrate// computeTime() 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        // computeTime()        calndr.set(GregorianCalendar.YEAR, 2016);        calndr.computeTime();          // Displaying the current date        System.out.println("The recent"                           + " date is: " + calndr.getTime());    }}

输出:

The Current date is: Wed Feb 13 16:27:12 UTC 2019The recent date is: Fri Jan 01 00:00:00 UTC 2016

例2 :

// Java Code to illustrate// computeTime() 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        // computeTime()        calndr.set(GregorianCalendar.YEAR, 2000);        calndr.computeTime();          // Displaying the current date        System.out.println("The recent"                           + " date is: " + calndr.getTime());    }}

输出:

The Current date is: Wed Feb 13 16:27:15 UTC 2019The recent date is: Sat Jan 01 00:00:00 UTC 2000

**参考资料: **https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html#computeTime()