I created

enum Restrictions{
  none,
  enumeration,
  fractionDigits,
  length,
  maxExclusive,
  maxInclusive,
  maxLength,
  minExclusive,
  minInclusive,
  minLength,
  pattern,
  totalDigits,
  whiteSpace;

  public Restrictions setValue(int value){
    this.value = value;
    return this;
  }
  public int value;
}

So that I could happily do something like this, which is perfectly legal syntax.

Restrictions r1 =
  Restrictions.maxLength.setValue(64);

The reason being is, I am using enum to restrict the type of restriction that could be used, and be able to assign a value to that restriction.

However, my actual motivation is to use that restriction in an @annotation.

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.FIELD, ElementType.METHOD})
public @interface Presentable {
  Restrictions[] restrictions() default Restrictions.none;
}

So that, I intended to do this:

@Presentable(restrictions=Restrictions.maxLength.setValue(64))
public String userName;

to which, the compiler croaks

The value for annotation enum attribute must be an enum constant expression.

Is there a way to accomplish what I wish to accomplish