Java YearMonth isSupported(TemporalField)方法及示例

YearMonth 类的 isSupported(TemporalField) 方法是用来检查指定的字段是否被YearMonth类所支持。

ChronoField支持的字段是。

• MONTH_OF_YEAR
• PROLEPTIC_MONTH
• YEAR_OF_ERA
• YEAR
• ERA

所有其他ChronoField实例将返回false。

语法

public boolean isSupported(TemporalField field)

参数： 该方法只接受一个参数 字段 ，代表要检查的字段。

返回值： 如果该字段在这个YearMonth上被支持，该方法返回布尔值true，如果不支持，则返回false。

下面的程序说明了isSupported(TemporalField)方法。

程序1 :

// Java program to demonstrate
// YearMonth.isSupported(TemporalField) method
  
import java.time.*;
import java.time.temporal.*;
  
public class GFG {
    public static void main(String[] args)
    {
        // Create a YearMonth object
        YearMonth thisYearMonth = YearMonth.of(2017, 8);
  
        // print instance
        System.out.println("YearMonth :"
                           + thisYearMonth);
  
        // apply isSupported() method
        boolean value
            = thisYearMonth.isSupported(
                ChronoField.PROLEPTIC_MONTH);
  
        // print result
        System.out.println("PROLEPTIC_MONTH Field is supported by YearMonth class: "
                           + value);
    }
}

输出。

YearMonth :2017-08
PROLEPTIC_MONTH Field is supported by YearMonth class: true

程序2

// Java program to demonstrate
// YearMonth.isSupported(TemporalField) method
  
import java.time.*;
import java.time.temporal.*;
  
public class GFG {
    public static void main(String[] args)
    {
        // Create a YearMonth object
        YearMonth thisYearMonth = YearMonth.of(2017, 8);
  
        // print instance
        System.out.println("YearMonth :"
                           + thisYearMonth);
  
        // apply isSupported() method
        boolean value
            = thisYearMonth.isSupported(
                ChronoField.HOUR_OF_DAY);
  
        // print result
        System.out.println("HOUR_OF_DAY Field is supported by YearMonth class: "
                           + value);
    }
}

输出。

YearMonth :2017-08
HOUR_OF_DAY Field is supported by YearMonth class: false

参考资料：
https://docs.oracle.com/javase/10/docs/api/java/time/YearMonth.html#isSupported(java.time.temporal.TemporalField)