How to Use Reflection to Access Fields with Enum Types of a Class in Java?

Java Reflection provides three enum-specific APIs:

• Class.isEnum() : Indicates whether this class represents an enum type
• Class.getEnumConstants() : Retrieves the list of enum constants defined by the enum in the order they're declared.
• java.lang.reflect.Field.isEnumConstant() : Indicates whether this field represents an element of an enumerated type

The following example shows how to get and set fields with Java Enum Types:

package com.xyzws;

import java.lang.reflect.Field;
import java.util.Arrays;
import static java.lang.System.out;

enum Color { 
    WHITE, BLACK, RED, YELLOW, BLUE;
}

public class Program {
	
    private Color color = Color.RED;
	
    public static void main(String... args)  {

    	
        Class c = Color.class;
        if (c.isEnum()) {
            out.format("Enum name:  %s%nEnum constants:  %s%n",
                        c.getName(), 
                        Arrays.asList(c.getEnumConstants()));
        }

        try {
            Program obj = new Program();
            Field f = obj.getClass().getDeclaredField("color");
            f.setAccessible(true);
            Color clr = (Color)f.get(obj);
            out.format("Original Color :  %s%n", clr);
            f.set(obj, Color.BLUE);
            out.format("     New Color :  %s%n", f.get(obj));
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        }
        
    }
}

/*
Enum name:  com.xyzws.Color
Enum constants:  [WHITE, BLACK, RED, YELLOW, BLUE]
Original Color :  RED
     New Color :  BLUE
*/

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