Crossorigin不起作用

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() {
    // ...
}