Fields in interfaces and annotations are automatically public static final, and methods are public abstract. Classes, interfaces or annotations nested in an interface or annotation are automatically public static (all nested interfaces and annotations are automatically static). Nested enums are automatically static. For historical reasons, modifiers which are implied by the context are accepted by the compiler, but are superfluous.

public @interface Annotation {
    public abstract void bar();     // both abstract and public are ignored by the compiler
    public static final int X = 0;  // public, static, and final all ignored
    public static class Bar {}      // public, static ignored
    public static interface Baz {}  // ditto
}
public interface Foo {
    public abstract void bar();     // both abstract and public are ignored by the compiler
    public static final int X = 0;  // public, static, and final all ignored
    public static class Bar {}      // public, static ignored
    public static interface Baz {}  // ditto
}
public class Bar {
    public static interface Baz {}  // static ignored
    public static enum FoorBar {    // static ignored
        FOO;
    }
}