Java Calendar ComputeFields()方法
Java Calendar类的computeFields()方法是受保护的抽象方法。它将当前毫秒时间值转换为fields []中的日历字段值。这可以与为日历对象设置的新时间与日历字段值同步。
语法
protected abstract void computeFields()
参数
NA
返回
此方法不返回任何值。
抛出
NA
示例1
import java.util.GregorianCalendar;
public class CalendarComputefieldExample1 extends GregorianCalendar{
public static void main(String[] args) {
// create a new calendar
CalendarComputefieldExample1 cal = new CalendarComputefieldExample1();
// print the current date
System.out.println("The current date is : " + cal.getTime());
// clear the calendar
cal.clear();
// set a new year and call computeFields()
cal.set(GregorianCalendar.YEAR, 3018);
System.out.println("New date is : " + cal.getTime());
cal.computeFields();
// print the current date
System.out.println("New date is : " + cal.getTime());
}
}
输出:
The current date is : Tue Jul 31 20:06:08 PDT 2018
New date is : Thu Jan 01 00:00:00 PST 3018
New date is : Thu Jan 01 00:00:00 PST 3018
示例2
import java.util.GregorianCalendar;
public class CalendarComputefieldExample2 extends GregorianCalendar{
public static void main(String[] args) {
// create a new calendar
CalendarComputefieldExample2 cal = new CalendarComputefieldExample2();
// print the current date
System.out.println("The current date is : " + cal.getTime());
// clear the calendar
cal.clear();
// set a new year and call computeFields()
cal.set(GregorianCalendar.MONTH, 10);
System.out.println("New date is : " + cal.getTime());
cal.computeFields();
// print the current date
System.out.println("New date is : " + cal.getTime());
}
}
输出:
The current date is : Tue Jul 31 20:14:45 PDT 2018
New date is : Sun Nov 01 00:00:00 PST 1970
New date is : Sun Nov 01 00:00:00 PST 1970
示例3
import java.util.GregorianCalendar;
public class CalendarComputefieldExample3 extends GregorianCalendar {
public static void main(String[] args) {
// create a new calendar
CalendarComputefieldExample3 cal = new CalendarComputefieldExample3();
// print the current date
System.out.println("The current date is : " + cal.getTime());
// clear the calendar
cal.clear();
// set a new year and call computeFields()
cal.set(GregorianCalendar.DAY_OF_MONTH, 10);
System.out.println("New date is : " + cal.getTime());
cal.computeFields();
// print the current date
System.out.println("New date is : " + cal.getTime());
}
}
输出:
The current date is : Tue Jul 31 20:19:24 PDT 2018
New date is : Sat Jan 10 00:00:00 PST 1970
New date is : Sat Jan 10 00:00:00 PST 1970
示例4
import java.util.GregorianCalendar;
public class CalendarComputefieldExample4 extends GregorianCalendar{
public static void main(String[] args) {
// create a new calendar
CalendarComputefieldExample4 cal = new CalendarComputefieldExample4();
// print the current date
System.out.println("The current date is : " + cal.getTime());
// clear the calendar
cal.clear();
// set a new year and call computeFields()
cal.set(GregorianCalendar.HOUR, 22);
cal.set(GregorianCalendar.SECOND, 400);
cal.set(GregorianCalendar.MINUTE, 70);
System.out.println("New date is : " + cal.getTime());
cal.computeFields();
// print the current date
System.out.println("New date is : " + cal.getTime());
}
}
输出:
The current date is : Tue Jul 31 20:21:45 PDT 2018
New date is : Thu Jan 01 23:16:40 PST 1970
New date is : Thu Jan 01 23:16:40 PST 1970
