Why does "Integer.TYPE" show error in annotation "attribute value must be constant"

Question

I've created an annotation:

@Target(ElementType.FIELD )
@Retention( RetentionPolicy.RUNTIME )
public @interface Test
{
    Class something();
}

But when I call it with Integer.TYPE (for the return type of an int), it shows the error.

public class TestA
{
    @Test(Integer.TYPE)
    public int id;
}

Answer 1

Class is not commensurate with the value Integer.TYPE

It is a compile-time error if the element type is not commensurate with the element value. An element type T is commensurate with an element value V if and only if one of the following is true:

• [...]

• If T is Class or an invocation of Class (§4.5), then V is a class literal (§15.8.2).

From the source code of Integer

public static final Class<Integer>  TYPE = (Class<Integer>) Class.getPrimitiveClass("int");

The expression Integer#TYPE is not a class literal. Integer.class or int.class would work, if that's what you're after.

Answer 2

Try using int.class instead of Integer.TYPE:

@Test(int.class)