In Java API for RESTful Web Services using Jersey, you can have the minimal url-pattern in the web.xml configuration file:

<url-pattern>/*</url-pattern>

But can’t skip annotations in the head of the class. That identifies where the url path starts.

@Path("/")
public class HelloWorldService

@ApplicationPath("/")
public class HelloApp extends Application

(Edit: Turns out you can skip the url-pattern in web.xml. You only need to specify the @Path and @ApplicationPath in the classes for Jersey 2.18).