Californium CoAP path parameters

Question

I'm working on a CoAP application using Eclipse Californium and I need to pass parameters using the URL as we do in restful web services. Is it possible to do it in californium coap implementation, and if so please let me know how to do it. ex:

coap://localhost:5683/foo/{fooID}

Answer 1

The short answer is yes you can do it.

As stated in JavaDocs

• When a request arrives at the server, the {@link ServerMessageDeliverer} searches in the resource tree for the destination resource. It travels down the resource tree by looking for one element of the destination URI after another and by calling the method {@link #getChild(String)} on each element. It is allowed to override this method and to return an arbitrary resource. This allows for instance to serve URIs with wildcards or delegate requests to any sub-URI to the same resource.

So basically you have to override deliverRequest and maybe findResource methods in org.eclipse.californium.core.server.ServerMessageDeliverer in order to return appropriate resource which will handle the request. Also it will be required to analyse Exchange Request UriPath as a part of resource handleGET/PUT/POST/etc to fetch path variable (this can be done by using CoapExchange.advanced().getRequest().getOptions().getUriPath())

Based on the source code of Californium it should be pretty easy to override the default behaviour of a request deliverer.

Good luck with that!