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Java Reflection - Field.isEnumConstant() Examples

Java Reflection Java Java API 

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Class:

java.lang.reflect.Field

java.lang.Objectjava.lang.Objectjava.lang.reflect.AccessibleObjectjava.lang.reflect.AccessibleObjectjava.lang.reflect.AnnotatedElementAnnotatedElementjava.lang.reflect.Fieldjava.lang.reflect.Fieldjava.lang.reflect.MemberMemberLogicBig

Method:

public boolean isEnumConstant()

Returns true if this field represents an element of an enumerated type; returns false otherwise.


Examples


package com.logicbig.example.field;

import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;

public class IsEnumConstantExample {
    private TimeUnit timeUnit;

    public static void main(String... args) throws NoSuchFieldException {
        Field field = IsEnumConstantExample.class.getDeclaredField("timeUnit");
        boolean v = field.isEnumConstant();
        System.out.println(v);
    }
}

Output

false




Checking all fields in TimeUnit.class:

package com.logicbig.example.field;

import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;

public class IsEnumConstantExample2 {

    public static void main(String... args) {
        Field[] declaredFields = TimeUnit.class.getDeclaredFields();
        Arrays.stream(declaredFields)
              .forEach(f ->
                      System.out.printf("Field name: %-12s, isEnumConstant: %s%n",
                              f.getName(), f.isEnumConstant()));

    }
}

Output

Field name: NANOSECONDS , isEnumConstant: true
Field name: MICROSECONDS, isEnumConstant: true
Field name: MILLISECONDS, isEnumConstant: true
Field name: SECONDS     , isEnumConstant: true
Field name: MINUTES     , isEnumConstant: true
Field name: HOURS       , isEnumConstant: true
Field name: DAYS        , isEnumConstant: true
Field name: NANO_SCALE  , isEnumConstant: false
Field name: MICRO_SCALE , isEnumConstant: false
Field name: MILLI_SCALE , isEnumConstant: false
Field name: SECOND_SCALE, isEnumConstant: false
Field name: MINUTE_SCALE, isEnumConstant: false
Field name: HOUR_SCALE  , isEnumConstant: false
Field name: DAY_SCALE   , isEnumConstant: false
Field name: scale       , isEnumConstant: false
Field name: maxNanos    , isEnumConstant: false
Field name: maxMicros   , isEnumConstant: false
Field name: maxMillis   , isEnumConstant: false
Field name: maxSecs     , isEnumConstant: false
Field name: microRatio  , isEnumConstant: false
Field name: milliRatio  , isEnumConstant: false
Field name: secRatio    , isEnumConstant: false
Field name: $VALUES     , isEnumConstant: false




package com.logicbig.example.field;

import java.lang.reflect.Field;
import java.util.Arrays;

public class IsEnumConstantExample3 {

    public static void main(String... args) {
        Field[] declaredFields = MyEnum.class.getDeclaredFields();
        Arrays.stream(declaredFields)
              .forEach(f ->
                      System.out.printf("Field name: %-12s, isEnumConstant: %s%n",
                              f.getName(), f.isEnumConstant()));
    }

    private static enum MyEnum {
        A, B, C
    }
}

Output

Field name: A           , isEnumConstant: true
Field name: B           , isEnumConstant: true
Field name: C           , isEnumConstant: true
Field name: $VALUES     , isEnumConstant: false

Note that $VALUES field is related to values() method in an enum (check out this example as well).

See Also