Which types can be used for Java annotation members?

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Today I wanted to create my first annotation interface following this documentation and I got this compiler error 

Invalid type for annotation member":
public @interface MyAnnotation {
    Object myParameter;
    ^^^^^^
}

Obviously Object cannot be used as type of an annotation member. Unfortunately I could not find any information on which types can be used in general.

This I found out using trial-and-error:

  • String → Valid
  • int → Valid
  • Integer → Invalid (Surprisingly)
  • String[] → Valid (Surprisingly)
  • Object → Invalid

Perhaps someone can shed some light on which types are actually allowed and why.

annotations java
5 Answers

According to Oracle the valid types for annotation elements are:

1. Primitives (byte, char, int, long float, double)
2. Enums
3. Class (Think generics here Class <?>, Class<? extends/super T>>)
4. String
5. Array of the above (array[] of primitives, enums, String, or Class)
5. Another annotation.

A plus to note, all elements are inherently considered public and abstract.

Therefore

 static final variable(s) allowed as well.
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