interface enum and updates

It’s a very bad idea to create an interface which is solely for declaring some constants without any methods. Here’s such an interface:
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public interface Color {
    public static final int RED = 0xff0000;
    public static final int BLACK = 0x000000;
    public static final int WHITE = 0xffffff;
}
It’s because the purpose of interfaces is for inheritance and polymorphism, not for static stuffs like that. So the best practice recommends us to use an enum instead. For example:
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public enum Color {
    BLACK, WHITE, RED
}
In case the color code does matter, we can update the enum like this:
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public enum Color {
 
    BLACK(0x000000),
    WHITE(0xffffff),
    RED(0xff0000);
 
    private int code;
 
    Color(int code) {
        this.code = code;
    }
 
    public int getCode() {
        return this.code;
    }
}

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what is the meaning of color code does not matter and updating like below?

In case the color code does matter, we can update the enum like this:
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public enum Color {
 
    BLACK(0x000000),
    WHITE(0xffffff),
    RED(0xff0000);
 
    private int code;
 
    Color(int code) {
        this.code = code;
    }
 
    public int getCode() {
        return this.code;
    }
}

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https://www.codejava.net/coding/10-java-core-best-practices-every-java-programmer-should-know

when we create special AppConstants class?
can there be interface just for constants?
please advise
LVL 7
gudii9Asked:
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Fabrice LambertConsultingCommented:
Hi,

Maybe take a look at the Services Locator design pattern.

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