JsonFilter with broken links

UserController.java

@RepositoryRestController
public class UserController {
    
    private final UserRepository userRepository;
    
    private final RepositoryEntityLinks links;
    
    public UserController(final UserRepository userRepository,
                          final RepositoryEntityLinks links) {
        
        this.userRepository = userRepository;
        this.links = links;
    }
    
    @GetMapping(value = "users/{id}", params = "fields")
    public ResponseEntity<MappingJacksonValue> getUser(@PathVariable("id") Long id,
                                                       @RequestParam(value = "fields") String fields,
                                                       HttpServletRequest request) {
        
        Resource<User> userResource = new Resource<>(userRepository.findOne(id));
        
        userResource.add(new Link(request.getRequestURL() + "?fields=" + fields).withSelfRel());
        userResource.add(links.linkToSingleResource(userResource.getContent()).withRel("user"));
        userResource.add(links.linkToSingleResource(userResource.getContent().getGroup()).withRel("group"));
        
        MappingJacksonValue wrapper = new MappingJacksonValue(userResource);
        
        wrapper.setFilters(new SimpleFilterProvider()
                                   .addFilter("userFilter",
                                              SimpleBeanPropertyFilter.filterOutAllExcept(fields.split(","))));
        return ResponseEntity.ok(wrapper);
    }
}