About Question enthuware.ocpjp.v11.2.3375 :

[cjgiron]

Where can I find the explanation for this question? Is there a resource that defines which annotations are defined with @Retention and explains why they are defined with that RetentionPolicy?

[admin]

1. All annotations have a Retention policy (it is one of SOURCE, CLASS, and RUNTIME).
2. No, there is no official document that lists all the annotations with their runtime policy. But if you remember this information for the annotations included in this question, you will be ready for the exam.
3. Setting a retention policy is a design decision depending on the purpose of the annotation i.e. what the annotation developer wants achieve with that annotation. For example, the @Override annotation is meant to check at compile time whether the method does really override a superclass method so that the developer can be warned of a coding mistake. This information has no use at runtime. So, the retention policy for this annotation is SOURCE.
Similarly, you can take any annotation, see what is its purpose and then decide whether you need that information at run time or not.