Need example of putting filter in Restlet Component

Question

I have a Restlet (v2.1.1) component that is using a ServerResource to process HTTP GET requests.

I would like to put filters and/or routers into the component so that they can do some processing before the request gets to the ServerResource.

I have been searching the Internet for an example of doing this, as well as reading the "Restlet in Action" book. I have discovered something interesting:

There are plenty of examples of how to set up a ServerResource within a component.

There are plenty of examples of how to create and set up filters and routers.

Unfortunately, search as I might, through the book and on the Internet, I cannot find an example of using both!

According to the book and the tutorials on the Internet, we should be able to create a component, set up a ServerResource in the component, and use a filter to preprocess requests that go to the ServerResource. None of the documentation anywhere seems to tell us exactly how to do this.

Am I misreading everything? Is there really no way to put filters or routers in components with ServerResources? Or have I missed some document somewhere that provides a real example of how to do this?

Could someone please either provide a simple example or provide a link to an example of doing this?

Thanks...

Answer 1

You need to attach the filter to the router and then attach the ServerResource to the filter using the method setNext(Class<? extends ServerResource> targetClass):

Filter myFilter = new MyFilter(getContext());
myFilter.setNext(MyServerResource.class);
router.attach("/test", myFilter);

Now you can preprocess using the filter's beforeHandle(Request request, Response response) method. If you return CONTINUE in this method, the filter will pass the request to the ServerResource.