Java year isSupported(TemporalField)方法及示例

Year 类的 isSupported(TemporalField) 方法用于检查指定的字段是否被Year类所支持，使用这个方法我们可以检查这个Year对象是否可以被查询到指定的字段。

ChronoField支持的字段是。

• 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： 如果该字段在该年支持，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
// Year.isSupported(TemporalField) method
 
import java.time.*;
import java.time.temporal.*;
 
public class GFG {
    public static void main(String[] args)
    {
        // create a Year object
        Year year = Year.of(2019);
 
        // print instance
        System.out.println("Year :"
                           + year);
 
        // apply isSupported() method
        boolean value
            = year.isSupported(
                ChronoField.YEAR_OF_ERA);
 
        // print result
        System.out.println("YEAR_OF_ERA Field is supported by Year class: "
                           + value);
    }
}

输出

Year :2019
YEAR_OF_ERA Field is supported by Year class: true

程序2

// Java program to demonstrate
// Year.isSupported(TemporalField) method
 
import java.time.*;
import java.time.temporal.*;
 
public class GFG {
    public static void main(String[] args)
    {
        // create a Year object
        Year year = Year.of(2022);
 
        // print instance
        System.out.println("Year :"
                           + year);
 
        // apply isSupported() method
        boolean value
            = year.isSupported(
                ChronoField.MILLI_OF_SECOND);
 
        // print result
        System.out.println("MilliSecond Field is supported: "
                           + value);
    }
}

输出

Year :2022
MilliSecond Field is supported: false

References:
https://docs.oracle.com/javase/10/docs/api/java/time/Year.html#isSupported(java.time.temporal.TemporalField)