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";
}
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.
@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
}
}
@GetMapping is an alias for @RequestMapping
@GetMapping is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.GET).
value method is an alias for path method.
This is an alias for path(). For example @RequestMapping("/foo") is equivalent to @RequestMapping(path="/foo").
So both methods are similar in that sense.
