Difference between path and value attributes in @RequestMapping annotation

Question

What is the difference between below two attributes and which one to use when?

@GetMapping(path = "/usr/{userId}") public String findDBUserGetMapping(@PathVariable("userId") String userId) {   return "Test User"; }  @RequestMapping(value = "/usr/{userId}", method = RequestMethod.GET) public String findDBUserReqMapping(@PathVariable("userId") String userId) {   return "Test User"; } 

Answer 1

As mentioned in the comments (and the documentation), value is an alias to path. Spring often declares the value element as an alias to a commonly used element. In the case of @RequestMapping (and @GetMapping, ...) this is the path property:

This is an alias for path(). For example @RequestMapping("/foo") is equivalent to @RequestMapping(path="/foo").

The reasoning behind this is that the value element is the default when it comes to annotations, so it allows you to write code in a more concise way.

Other examples of this are:

• @RequestParam (value → name)
• @PathVariable (value → name)
• ...

However, aliases aren't limited to annotation elements only, because as you demonstrated in your example, @GetMapping is an alias for @RequestMapping(method = RequestMethod.GET).

Just looking for references of AliasFor in their code allows you to see that they do this quite often.

Answer 2

@GetMapping is a shorthand for @RequestMapping(method = RequestMethod.GET).

In your case. @GetMapping(path = "/usr/{userId}") is a shorthand for @RequestMapping(value = "/usr/{userId}", method = RequestMethod.GET).

Both are equivalent. Prefer using shorthand @GetMapping over the more verbose alternative. One thing that you can do with @RequestMapping which you can't with @GetMapping is to provide multiple request methods.

@RequestMapping(value = "/path", method = {RequestMethod.GET, RequestMethod.POST, RequestMethod.PUT) public void handleRequet() {  } 

Use @RequestMapping when you need to provide multiple Http verbs.

Another usage of @RequestMapping is when you need to provide a top level path for a controller. For e.g.

@RestController @RequestMapping("/users") public class UserController {      @PostMapping     public void createUser(Request request) {         // POST /users         // create a user     }      @GetMapping     public Users getUsers(Request request) {         // GET /users         // get users     }      @GetMapping("/{id}")     public Users getUserById(@PathVariable long id) {         // GET /users/1         // get user by id     } }