Why Use PathVariable instead of PathParam? - rest

Question

Before marking this as duplicate, just wanted you guys to know I have checked out the question posted here:
What is the difference between #PathParam and #PathVariable
Thing is, if the usage of PathParam and PathVariable are same (only that one is from the JAX-RS API and one is provided by Spring), why is it that using one gives me null and the other gives me the proper value?
I am using Postman to invoke the service as:
http://localhost:8080/topic/2
(I'm very new to SpringBoot)
Using PathParam :
import javax.websocket.server.PathParam;
import org.apache.tomcat.util.json.ParseException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
#RestController
public class TopicController {
#Autowired
TopicService topicService;
#RequestMapping(method=RequestMethod.GET,path="/topic/{id}")
public Topic getById(#PathParam("id") long id) throws ParseException {
return topicService.getTopicById(id); //-- here id comes as null (when id is declared as a wrapper type - Long, else it throws an error)
}
}
Using PathVariable:
#RestController
public class TopicController {
#Autowired
TopicService topicService;
#RequestMapping(method=RequestMethod.GET,path="/topic/{id}")
public Topic getById(#PathVariable("id") long id) throws ParseException {
return topicService.getTopicById(id); //-- here id comes as 2
}
}

Answer 1

I think the pathparam in your project is under javax.ws... This one is not what they talked about. It is used in websocket, which means it is not a http annotaiton. JBoss implement pathparam needs additional jars.