Java的.time.temporal.WeekFields类在Java中

WeekFields类表示周的定义，以提供 TemporalField 实例。 WeekFields 提供了五个字段，weekOfYear()、weekOfMonth()、dayOfWeek()、weekOfWeekBasedYear() 和 weekBasedYear()，它们提供对来自任何时间对象的值的访问。

每个不同的 WeekField 都需要一个单独的 Field 实例，并且需要：

• 一周开始
• 最少天数

类声明：

public final class WeekFields
extends Object
implements Serializable

WeekFields 类从类Java.lang.Object继承以下方法：

• 克隆（）
• 完成（）
• 获取类（）
• 通知（）
• 通知所有（）
• 等待（）

WeekFields 类的方法：

Method	Description
dayOfWeek()	This method returns a field to access the day of the week based on this WeekFields.
equals(Object object)	This method checks if this WeekFields is equal to the specified object.
getFirstDayOfWeek()	This method gets the first day-of-week.
getMinimalDaysInFirstWeek()	This method gets a minimal number of days in the first week.
hashCode()	This method returns a hash code for this WeekFields.
of(DayOfWeek firstDayOfWeek, int minimalDaysInFirstWeek)	This method obtains an instance of WeekFields from the first day-of-week and minimal days.
of(Locale locale)	This method obtains an instance of WeekFields appropriate for a locale.
toString()	This method gets a string representation of this WeekFields instance.
weekBasedYear()	This method returns a field to access the year of a week-based-year based on this WeekFields.
weekOfMonth()	This method returns a field to access the week of month based on this WeekFields.
weekOfWeekBasedYear()	This method returns a field to access the week of a week-based-year based on this WeekFields.
weekOfYear()	This method returns a field to access the week of year based on this WeekFields.

示例 1：

Java

// Java program to demonstrate
// WeekFields class
  
import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.temporal.TemporalField;
import java.time.temporal.WeekFields;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create WeekFields
        WeekFields weekFields
            = WeekFields.of(DayOfWeek.MONDAY, 1);
  
        // creating separate temporal fields for each method
  
        // apply dayOfWeek()
        TemporalField dayOfWeek = weekFields.dayOfWeek();
  
        // apply weekBasedYear()
        TemporalField weekBasedYear
            = weekFields.weekBasedYear();
  
        // apply weekOfMonth()
        TemporalField weekOfMonth
            = weekFields.weekOfMonth();
  
        // apply weekOfWeekBasedYear()
        TemporalField weekOfWeekBasedYear
            = weekFields.weekOfWeekBasedYear();
  
        // create a LocalDate
        LocalDate day = LocalDate.of(2021, 03, 31);
  
        // get day of week for localdate
        int dow = day.get(dayOfWeek);
  
        // get week based year for localdate
        int wby = day.get(weekBasedYear);
  
        // get week of month for localdate
        int wom = day.get(weekOfMonth);
  
        // get week of week for localdate
        int wow = day.get(weekOfWeekBasedYear);
  
        // print results
  
        System.out.println("day of week for " + day + " :"
                           + dow);
        System.out.println("week based year for " + day
                           + " :" + wby);
        System.out.println("week of month for " + day + " :"
                           + wom);
        System.out.println("Week of week for " + day + " :"
                           + wow);
    }
}

输出

day of week for 2021-03-31 :3
week based year for 2021-03-31 :2021
week of month for 2021-03-31 :5
Week of week for 2021-03-31 :14

示例 2：

Java

// Java program to demonstrate
// WeekFields class
  
import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.temporal.TemporalField;
import java.time.temporal.WeekFields;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create WeekFields
        WeekFields weekFields
            = WeekFields.of(DayOfWeek.SUNDAY, 1);
  
        // creating separate temporal fields for each method
  
        // apply dayOfWeek()
        TemporalField dayOfWeek = weekFields.dayOfWeek();
  
        // apply weekBasedYear()
        TemporalField weekBasedYear
            = weekFields.weekBasedYear();
  
        // apply weekOfMonth()
        TemporalField weekOfMonth
            = weekFields.weekOfMonth();
  
        // apply weekOfWeekBasedYear()
        TemporalField weekOfWeekBasedYear
            = weekFields.weekOfWeekBasedYear();
  
        // create a LocalDate
        LocalDate day = LocalDate.of(2021, 12, 05);
  
        // get day of week for localdate
        int dow = day.get(dayOfWeek);
  
        // get week based year for localdate
        int wby = day.get(weekBasedYear);
  
        // get week of month for localdate
        int wom = day.get(weekOfMonth);
  
        // get week of week for localdate
        int wow = day.get(weekOfWeekBasedYear);
  
        // print results
  
        System.out.println("day of week for " + day + " :"
                           + dow);
        System.out.println("week based year for " + day
                           + " :" + wby);
        System.out.println("week of month for " + day + " :"
                           + wom);
        System.out.println("Week of week for " + day + " :"
                           + wow);
    }
}

输出

day of week for 2021-12-05 :1
week based year for 2021-12-05 :2021
week of month for 2021-12-05 :2
Week of week for 2021-12-05 :50