Return code error as ResponseEntity after DTO validation in REST API

Using the https://www.leveluplunch.com/java/tutorials/017-validate-spring-rest-webservice-request/ tutorial, I want to validate the form using java without reloading the page. I do this in the REST API. My controller

@PutMapping(value = "/changeEmail", consumes = MediaType.APPLICATION_JSON_VALUE)
public HttpEntity<ChangeEmailDTO> showChangeEMail(
        @RequestBody @Valid ChangeEmailDTO changeEmailDTO,
        BindingResult result
) {
    System.out.println("Email: " + changeEmailDTO.getEmail());

    if(result.hasErrors()) {
        System.out.println("Error: " + changeEmailDTO.getEmail());
        return ResponseEntity.badRequest().body(changeEmailDTO);
    }

    System.out.println("Success: " + changeEmailDTO.getEmail());
    return ResponseEntity.ok(changeEmailDTO);
}

Accepts email address, validates in annotations

    @NotEmpty
   @Getter @Setter private String email;

According to the above guide, it is supposed to return an error code in json form. The only effect it receives is https://zapodaj.net/81a6db4635168.png.html. So it returns the object itself, not like in the tutorial

{"timestamp":1417379464584,"status":400,"error":"Bad Request","exception":"org.springframework.web.bind.MethodArgumentNotValidException","message":"Validation failed for argument at index 0 in method: public org.springframework.http.ResponseEntity<demo.AgencyResource> demo.AgencyController.saveAgency(demo.AgencyResource), with 2 error(s): [Field error in object 'agencyResource' on field 'name': rejected value [null]; codes [NotNull.agencyResource.name,NotNull.name,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [agencyResource.name,name]; arguments []; default message [name]]; default message [may not be null]] [Field error in object 'agencyResource' on field 'id': rejected value [50]; codes [Max.agencyResource.id,Max.id,Max.java.lang.Integer,Max]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [agencyResource.id,id]; arguments []; default message [id],20]; default message [must be less than or equal to 20]] ","path":"/agencies"}

How to return such data?