Well... you can't do this:

@Foo(values={MyEnum.FOO,  MyEnum.BAR});

@interface Foo {
 Object[] values() default {};
}

James Carman wrote:
What do you mean by "Enums as Objects"?

On Thu, Dec 4, 2008 at 11:11 PM, Bruno Borges <[EMAIL PROTECTED]>wrote:

Well... You don't have to create one java file for each class. You can put
all of them on the same file, like:

public final class MyAppRoles {
  private MyAppRoles() {}
  public static final class Admin extends Role {
      private Admin() {}
  }

  public static final class User extends Role {
      private User() {}
  }
}

Note that this is really type-safe, and these classes will never be
instantiated.
But, I'm not defending that we should change that. I'm just showing a
possibility. :-)

I really did't understand why Sun decided to reject Enums as Objects in
this context of annotations.

cheers,
Bruno

James Carman wrote:

I don't know about this.  It would work (and break existing code, unless
you
use something other than value for the annotation).  I don't know if I
would
want to have to create a new class for each role in my project.  Yes, it
would be a small price to pay, but it just feels wrong.

On Thu, Dec 4, 2008 at 10:33 PM, Bruno Borges <[EMAIL PROTECTED]
wrote:

I've found a way to implement a type-safe check for this. Here it goes:

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@AuthorizeInstantiation(value = { User.class, Admin.class })
public class EnumAnnotation {

}

@Retention(RetentionPolicy.RUNTIME)
@Target( { ElementType.PACKAGE, ElementType.TYPE })
@Documented
@Inherited
@interface AuthorizeInstantiation {

 Class<? extends Role>[] value() default {};

}

class Role {
}

class User extends Role {
}

class Admin extends Role {
}

So, the only thing that must change is the annotation
@AuthorizeInstantiation, to accept classes that extends roles.

Thoughts anyone?

cheers,
Bruno



Bruno Borges wrote:



You simply can't do that because the nature of Annotations.

Even if AuthorizeInstantiation's values were of type Object[] you
wouldn't
be able to do that with Enums.

You will have to use Strings.

Although there's some hack you can make using Java 6 to accomplish what
you want. If you are interested, take a look at this link:

http://www.iam.unibe.ch/~akuhn/blog/2008/roman-numerals-in-your-java/<http://www.iam.unibe.ch/%7Eakuhn/blog/2008/roman-numerals-in-your-java/>
<
http://www.iam.unibe.ch/%7Eakuhn/blog/2008/roman-numerals-in-your-java/
Good luck!!

Cheers,
Bruno

miro wrote:



I am using this  @AuthorizeInstantiation   (wicket authetication
annotation)
in my pages , the code for this annotation

@Retention(RetentionPolicy.RUNTIME)
@Target( { ElementType.PACKAGE, ElementType.TYPE })
@Documented
@Inherited
public @interface AuthorizeInstantiation {

  /**
   * Gets the roles that are allowed to take the action.
   *      * @return the roles that are allowed. Returns a zero length
array by
default
   */
  String[] value() default {};
}


I created my enum with representing authorities

public enum  Authorities {
      LIASION_OFFICER,
  GRANTS_OFFICER,
  PROGRAM_ANALYST,
  ADMIN;

}

I am trying to use  AuthorizeInstantiation   in my page  here an
example
@AuthorizeInstantiation(value={Authorities.LIASION_OFFICER.name()})
public class HomePage extends BasePage {


this line does not compile, I get the error
The value of annotation attribute AuthorizeInstantiation .value must be
a
constant expression  .please help me resolve this .




---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]





---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]




---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to