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 feels 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 void getAllItems()
{
System.out.println("GET");
}
@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?
Thanks