Enum static arrays and annotation values confusion

Question

I have enum:

public enum Scope {
    USER, GLOBAL;

    public static final Scope[] TRANSIENT = {};
    public static final Scope[] USER_OVER_GLOBAL = {GLOBAL, USER};
    public static final Scope[] GLOBAL_OVER_USER = {USER, GLOBAL};
}

and annotation:

public @interface Config {
    public Scope[] load() default Scope.GLOBAL_OVER_USER; // Can't use this defval

    public Scope[] save() default Scope.USER;
}

Why I can't use static arrays as default values for annotation's property? My NetBeans 7.3 Beta tell me there is required Scope but found Scope[] - as you can see this not true. Is there a NB's or Java 7 related confusion?

Are you sure that error is occurring on the line illustrated? Because your code as shown should fail on the line below it. — Perception
– Perception, Commented Nov 13, 2012 at 11:51
@Perception: this is annotation, so USER is treated as {USER} and it's not a mistype. Problem is with using static hand-made values for annotation's defaults. — kbec
– kbec, Commented Nov 13, 2012 at 12:05

matsev · Accepted Answer · 2012-11-13 11:55:29Z

4

The problem is that the Scope[] GLOBAL_OVER_USER is not all constant. (Yes, the array itself is constant, however you can change the contents of it e.g. GLOBAL_OVER_USER[0] = GLOBAL;.

A workaround is to initiate the array directly in the annotation declaration:

public Scope[] load() default {USER, GLOBAL};

answered Nov 13, 2012 at 11:55

matsev

34k18 gold badges128 silver badges169 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

kbec Over a year ago

I know this workaround, but then how to get default value for this annotation property without its instance?

matsev Over a year ago

Well, you don't have to. By just adding @Config (or @Config(save=Scope.GLOBAL) ) the annotation's load value will keep it's default value.

kbec Over a year ago

Of course, but imagine case when you don't annotate field to imply annotation defaults.

kbec Over a year ago

There is a way for getting annotation's defaults.

Collectives™ on Stack Overflow

Enum static arrays and annotation values confusion

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related