The annotation returned by this method could contain an element whose value is of type Class.
This value cannot be returned directly: information necessary to locate and load a class (such as the class loader to use) is not available, and the class might not be loadable at all.
Attempting to read a Class object by invoking the relevant method on the returned annotation
will result in a MirroredTypeException, from which the corresponding TypeMirror may be extracted. Similarly, attempting to read a Class[]-valued element will result in a MirroredTypesException.

ということで、MirroredTypesExceptionを原因としたAnnotationFormatErrorにやられていますw。Class型およびClass[]型がなけりゃいいのでしょうが、Ikushipeはあいにくそればっかりなのでした。うかつにも前に今は亡きJAVA PRESSで記事書いたときより、今に至るまで知らなかった。。。

TypeDeclaration td = ...
for(AnnotationMirror am: typeDecl.getAnnotationMirrors()) {
  AnnotationType at = am.getAnnotationType();
  AnnotationTypeDeclaration atd = at.getDeclaration();
  if(Foo.class.getName().equals(atd.getQualifiedName())) {
    Map<AnnotationTypeElementDeclaration, AnnotationValue> map =
    for(AnnotationTypeElementDeclaration ated: map.keySet()) {
      if("bar".equals(ated.getSimpleName())) {
        AnnotationValue av = map.get(ated);
        Object value = av.getValue();
        if(value instanceof DeclaredType) {
          DeclaredType dt = (DeclaredType)value;
          return dt.getDeclaration().getQualifiedName();
        } else {
          throw new IllegalStateException();