How to initialize Jersey with a a specific resource instance with specific MessgeBodyReaders/Writers??

Question

I'm trying to start Jersey on a preconfigured port/url with a preconfigured resource instance. I can't quite figure out how to correctly do it.

Here is a snippet of a code. Help me, please, fill in the blanks:

@Component
@PerRequest
@Path("/svc")
@Consumes({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
@Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
public class MyService
{
    // This piece is known
}

public class JSONMessageBodyWriter implements MessageBodyWriter<Object>
{
    // This piece is known
}

public class XMLMessageBodyWriter implements MessageBodyWriter<Object>
{
    // This piece is known
}

// This is where I need help
MyService service = new MyService();
...
HttpHandler handler = ???
...
HttpServer server = ???
server.createContext("/services", handler);
...
server.start();

In the snippet above, I'm trying to expose the MyService via the http://localhost:8080/services/svc url. If the JSONMessageBodyWriter and the XMLMessageBodyWriter will be plugged in - the service will work vis XML and JSON accordingly.

If you know how to do this on Jetty or Grizzly, let me know too. Can Spring help here?

Answer 1

Jersey itself provides an entire set of examples, and specifically the simplest helloworld example shows how to start a server on a port to either just run it or test against in JUnits. If you look at that, you'll get example for how to setup and start a server.

Now, on configuring MessageBodyReaders and MessageBodyWriters as part of a jersey application, you'll find that this is covered by the JAX-RS spec itself (which jersey implements). First off, your reader and writer need the @Provider annotation. Additionally, the reader should get the @Consumes annotation, and the writer should get the @Produces annotation, so you can specify what mime-type(s) they consume and produce, respectively.

Next is activating them. The helloworld example above won't show that, because it doesn't use custom readers or writers (another example might, I didn't look). So instead of supplying the package to find resources (as they do; you'll know what I speak of when you see the helloworld example), you'll code a subclass of Application, where you specify your resource class and the reader/writer classes. With the reader and writer you have the option of specifying either a class (that you return from getClasses), or providing an already created instance yourself (that you return from getSingletons).

Finally, specify the name of your Application sub-class as the value of init-parameter "javax.ws.rs.Application". The init-params can be passed to GrizzlyWebContainerFactory.create (again, you'll see this used in the example) when you start the server.

Hope this helps.