Java REST: @GET and @PUT at the same path?

Question

I have currently trying to learn the basics of Java REST, using JAX-RS.

Within the UserService class (near bottom) of this example there is both an @GET AND @PUT method with the same @path annotation:

@GET
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
public List<User> getUsers() {
   return userDao.getAllUsers();
}

and

@PUT
@Path("/users")
@Produces(MediaType.APPLICATION_XML)
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public String createUser(@FormParam("id") int id,
   @FormParam("name") String name,
   @FormParam("profession") String profession,
   @Context HttpServletResponse servletResponse) throws IOException {
   User user = new User(id, name, profession);
   int result = userDao.addUser(user);
   if(result == 1) {
      return SUCCESS_RESULT;
   }

   return FAILURE_RESULT;
}

How does the Program know which method to invoke, considering that they are both point at the same @path ?

Answer 1

Resource classes have methods that are invoked when specific HTTP method requests are made, referred to as resource methods. In order to create Java methods that will be invoked with specific HTTP methods, a regular Java method must be implemented and annotated with one of the JAX-RS @HttpMethod annotated annotations (namely, @GET, @POST, @PUT, and @DELETE).

For more info take a look at this example1 and example2