/**
* Sorts the elements according to their order:
*
* <ol>
* <li>If an {@link Order} annotation is present, its {@link Order#value()} is used
* <li>If a {@link Replace} annotation is present, the superclass' order is used
* <li>If the object implements {@link IOrdered}, {@link IOrdered#getOrder()} is used
* <li>Finally, the index in the original collection is used
* </ol>
*
* @since 3.8.1
*/
public static <T> Collection<T> sortByOrder(Collection<T> list) {
if (list == null) {
return null;
}
TreeMap<CompositeObject, T> sortMap = new TreeMap<CompositeObject, T>();
int index = 0;
for (T element : list) {
Class<?> c = element.getClass();
double order;
Order orderAnnotation;
while ((orderAnnotation = c.getAnnotation(Order.class)) == null
&& c.isAnnotationPresent(Replace.class)) {
c = c.getSuperclass();
}
if (orderAnnotation != null) {
order = orderAnnotation.value();
} else if (element instanceof IOrdered) {
order = ((IOrdered) element).getOrder();
} else {
order = (double) index;
}
sortMap.put(new CompositeObject(order, index), element);
index++;
}
return sortMap.values();
}
/**
* Filters the given class array and sorts the remaining elements according to their {@link Order}
* annotation.
*
* <p>By default, the method throws an {@link IllegalArgumentException} if one of the remaining
* classes is not annotated by {@link Order}. The behavior can be switched off by setting the
* system property <code>bsi.debug.innerclass.order</code> to an arbitrary value.
*
* @param classes
* @param filter
* @return
* @throws IllegalArgumentException
*/
@SuppressWarnings("unchecked")
public static <T> Class<T>[] sortFilteredClassesByOrderAnnotation(
Class[] classes, Class<T> filter) {
TreeMap<CompositeObject, Class> orderedClassesMap = new TreeMap<CompositeObject, Class>();
for (int i = 0; i < classes.length; i++) {
if (filter.isAssignableFrom(classes[i])) {
if (classes[i].isAnnotationPresent(Order.class)) {
Order order = (Order) classes[i].getAnnotation(Order.class);
orderedClassesMap.put(new CompositeObject(order.value(), i), classes[i]);
} else {
if (!classes[i].isAnnotationPresent(Replace.class)) {
LOG.error("missing @Order annotation: " + classes[i].getName());
}
orderedClassesMap.put(new CompositeObject(Double.MAX_VALUE, i), classes[i]);
}
}
}
return orderedClassesMap.values().toArray(new Class[orderedClassesMap.size()]);
}