如何在Undertow中处理HTTP方法？

Question

So I've decided to start using Undertow, both as an experiment and due to the great results it achieved in benchmark tests. And while I think it's fantastic there's a feature which is either missing or I can't find.

I want to develop a RESTful web service so it's important for me to identify which HTTP method is being called. Now I can get this from RequestMethod in the HttpServerExchange parameter but if had to that for every handler that would become tedious.

My solution, which works but I know is wrong, is this:

Created an annotation interface called HTTPMethod:

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD) 
public @interface HTTPMethod {

public enum Method {

    OTHER, GET, PUT, POST, DELETE
}

Method method() default Method.OTHER;

an "abstract" class (which is not abstract):

public abstract class RESTfulHandler implements HttpHandler {

@Override
public void handleRequest(HttpServerExchange hse) throws Exception {

    for (Method method : this.getClass().getDeclaredMethods()) {

        // if method is annotated with @Test
        if (method.isAnnotationPresent(HTTPMethod.class)) {

            Annotation annotation = method.getAnnotation(HTTPMethod.class);
            HTTPMethod test = (HTTPMethod) annotation;

            switch (test.method()) {
                case PUT:
                    if (hse.getRequestMethod().toString().equals("PUT")) {
                        method.invoke(this);
                    }
                    break;

                case POST:
                    if (hse.getRequestMethod().toString().equals("POST")) {
                        method.invoke(this);
                    }
                    break;

                case GET:
                    if (hse.getRequestMethod().toString().equals("GET")) {
                        method.invoke(this);
                    }
                    break;

                case DELETE:
                    if (hse.getRequestMethod().toString().equals("DELETE")) {
                        method.invoke(this);
                    }
                    break;
                case OTHER:
                    if (hse.getRequestMethod().toString().equals("OTHER")) {
                        method.invoke(this);
                    }
                    break;
            }
            if (test.method() == HTTPMethod.Method.PUT) {
                method.invoke(this);
            }
        }
    }
}

}

and an implementation of both the above:

public class ItemHandler extends RESTfulHandler{

@HTTPMethod(method=GET)
public List<String> getAllItems()
{
    System.out.println("GET");
    return new ArrayList<>();
}

@HTTPMethod(method=POST)
public void addItem()
{      
    System.out.println("POST");        
}

@HTTPMethod
public void doNothing()
{   
    System.out.println("OTHERS");      
}

}

Now as I said, it works, but I'm sure that the abstract class and it's implementation have something missing so that they glue correctly. So my question is two fold:

1) Is there a better / proper way to filter HTTP requests in Undertow? 2) What is the correct way of using annotations correctly correctly in the above case?

Answer 1

Managed to find several answers with the help of the Redhat team and Undertow contributors, hope this helps someone else:

1) The latest version of Undertow has a io.undertow.server.RoutingHandler class which does the exact same thing I propose, just without the need of annotations.

2) There's an adapter for RESTEasy by JBoss: resteasy-undertow or a custom framework hammock which includes RESTEasy + Undertow + Weld.

3) Undertow already supports Servlets 3, so they can be combined to use annotations if you prefer.