Anatomia de uma solução - VRaptor linkTo para jsp

LinkToHandler.java

@Component
@ApplicationScoped
public class LinkToHandler implements StereotypeHandler {

	private Map<String, Map<String, Linker>> linkTo = Maps.newHashMap();
	private final ServletContext context;
	private final Router router;

	public LinkToHandler(ServletContext context, Router router) {
		this.context = context;
		this.router = router;
		context.setAttribute("linkTo", linkTo); //para ficar disponível para todos os jsps
	}

	public void handle(Class<?> type) {
		String controller = type.getSimpleName();
		context.setAttribute(controller, controller); //para poder usar linkTo[ProdutoController]

		Map<String, Linker> methodMap = Maps.newHashMap();

		List<Method> methods = new Mirror().on(type).reflectAll().methods();
		for (Method method : methods) {
			if (!method.getDeclaringClass().equals(Object.class)) { 
				methodMap.put(method.getName(), new Linker(type, method));
			}
		}

		linkTo.put(controller, methodMap);
	}

	public Class<? extends Annotation> stereotype() {
		return Resource.class;
	}

	class Linker extends ForwardingMap<Object, Linker> {

		private final Method method;
		private final Class<?> type;
		private final Object[] args;
		private final int index;

		public Linker(Class<?> type, Method method) {
			this(type, method, new Object[method.getParameterTypes().length], 0);
		}
		public Linker(Class<?> type, Method method, Object[] args, int index) {
			this.type = type;
			this.method = method;
			this.args = args;
			this.index = index;
		}

		@Override
		protected Map<Object, Linker> delegate() {
			return Maps.newHashMap();
		}

		@Override
		public Linker get(Object key) {
			Object[] newArgs = args.clone(); //evitando cache indesejável de args
			newArgs[index] = key;
			return new Linker(type, method, newArgs, index + 1);
		}

		@Override
		public String toString() {
			return router.urlFor(type, method, args);
		}

	}

}