JAnnotation jaxbAnnotation = new JAnnotation(XmlJavaTypeAdapter.class);
jaxbAnnotation.addElement(new JAnnotationElement("value", adapter));
if (jn instanceof JavaParameter) {
JavaParameter jp = (JavaParameter)jn;
jp.addAnnotation("XmlJavaTypeAdapter", jaxbAnnotation);
} else if (jn instanceof JavaMethod) {
JavaMethod jm = (JavaMethod)jn;
jm.addAnnotation("XmlJavaTypeAdapter", jaxbAnnotation);
} else {
throw new RuntimeException("Annotation of " + jn.getClass() + " not supported.");