How to use constants definded in other class file as the default value in a custom annotation

Question

I hava below custom annotation,

@Inherited
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnno {

    String value() default "";

    // use constants value defined in other file
    int capacity() default com.constant.Constant.MAX_DATA_ROW;
}

I got a compile error say:

"Attribute value must be constant"

I don't want to write a direct value to default but I want to refer it from other class. so how can I accomplish that ?

It works when `MAX_DATA_ROW` is `static final` – Héctor Jul 13 '18 at 08:33 — Héctor, Jul 13 '18 at 08:33
seems it doesn't recognize your value as a constant. – Stultuske Jul 13 '18 at 08:35 — Stultuske, Jul 13 '18 at 08:35

Héctor · Accepted Answer · 2018-07-13T08:42:37.150

1

You must define MAX_DATA_ROW as static and final:

public class Constant {

    public static final int MAX_DATA_ROW = 1;

}

edited Jul 13 '18 at 08:42

answered Jul 13 '18 at 08:36

Héctor

24,444
35
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score 1 · Answer 2 · answered Jul 13 '18 at 08:37

1

Your constant MAX_DATA_ROW must be "public static final", otherwise it isn't a real constant.

answered Jul 13 '18 at 08:37

Alexander

54
5

How to use constants definded in other class file as the default value in a custom annotation

2 Answers2