Crossorigin doesn't work - spring

Question

React keep me saying Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://localhost:8080/users. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
The strange think it worked to me and it stopped working without any change to the controller code...
UserController.java
#RestController
#CrossOrigin
#RequestMapping(value = "/users")
public class UserController {
#Autowired
private UserService userService;
#RequestMapping(value = "/{userId}", method = RequestMethod.GET)
private User findOne(#PathVariable("userId") Integer userId) {
return userService.findOne(userId);
}
#RequestMapping(method = RequestMethod.GET)
private List<User> findAll() {
return userService.findAll();
}
#RequestMapping(method = RequestMethod.POST)
private User create(#RequestBody User user) {
user.setId(null); // To ensure we create instead of update
return userService.save(user);
}
#RequestMapping(value = "/{userId}", method = RequestMethod.PUT)
private User update(#PathVariable("userId") Integer userId, #RequestBody User user) {
user.setId(userId); // To ensure we update instead of create
return userService.save(user);
}
#RequestMapping(value = "/{userId}", method = RequestMethod.DELETE)
private void delete(#PathVariable("userId") Integer userId) {
final User user = userService.findOne(userId);
userService.delete(user);
}
}
and this is my fetch on React
fetch('http://localhost:8080/users', {
method: 'GET',
headers: {
'content-type': 'application/json'
},
}).then(response => { return response.json();
}).then(data => {
this.setState({users:data});
});
}
Any reason why it stopped working suddenly?
edit:
I tried making a clean new maven project and copied all packages into the new project and now it works, but I still don't know why it stopped work, the code is the same and now its working.

Answer 1

If you are using Spring Security and want CORS globally in your project then try to add it to the configuration:
#Override
protected void configure(HttpSecurity httpSecurity) throws Exception {
httpSecurity
.cors()
.and()
........ other config
}
But before that try the following approaches. To apply CORS on class level use it like this:
#CrossOrigin(origins = "http://domain2.com", maxAge = 3600)
#Controller
public class SomeController{
}
or use it in method level like this:
#CrossOrigin("http://example.com")
#RequestMapping("/some")
public Account retrieve() {
// ...
}
OR
#CrossOrigin(origins = "*")
#RequestMapping("/some")
public Account retrieve() {
// ...
}