Spring Boot REST path mapping

Question

I'm just thinking, what is the best practice to create PATH mapping for rest service. Let's say we have following paths:

/users POST
/users/1 PATCH, GET
/users/1/contacts GET, POST
/users/1/contacts/1 GET, PATCH

The question is - what is the best practice to create controllers. For example we have UserController where we technically could put all these mappings. Or - we should create seperate controllers (UserController, ContactsController). f.e UserController below, if we put everything under.

@RequestMapping("users")
@RestController
public class UserController {

    @RequestMapping(method = RequestMethod.POST)
    public ResponseEntity<Void> createUser() {}

    @RequestMapping(method = RequestMethod.GET)
    public User getUser() {}

    @RequestMapping(value = "{id}/contacts", method = RequestMethod.GET)
    public List<Contact> getContacts() {}

    @RequestMapping(value = "{id}/contacts", method = RequestMethod.POST)
    public ResponseEntity<Void> createContact() {}

    .....
}

And if we create separate controllers, how paths should be organized then? Probably it's a silly question, but i will be glad, if someone could share experience.

Answer 1

Lets suggest that number of entities related to User will increase in future. So it obvious that it is better to split it according to entities:

UserController -> UserService -> UserRepository,

ContactController -> ContactService -> ContactRepository,

FriendshipController -> FriendshipService -> FriendshipRepository

From my experience, User Controller

@RestController
@RequestMapping("/user")
public class UserController extends AbstractController {

...

   @RequestMapping(method = RequestMethod.POST)
   public ResponseEntity<?> createUser(@RequestHeader("X-Auth-Token") Optional<String> @RequestBody User user) {

...

   @RequestMapping(method = RequestMethod.GET)
   public ResponseEntity<?> listUsers(@RequestHeader("X-Auth-Token") Optional<String> authToken) {
...

related to user scope Friendship controller:

@RestController
@RequestMapping("/user/{id}")
public class FriendshipController extends AbstractController {

...

@RequestMapping(value = "/friendship/code", method = RequestMethod.POST)
    public ResponseEntity<?> generateCodeForUser(@PathVariable("id") long id) {

...

 @RequestMapping(value = "/friendship/code", method = RequestMethod.GET)
    public ResponseEntity<?> retrieveCodeForUser(@PathVariable("id") long id) {

...

Not sure it is axiom, but help me organize my code.