I need to have my own error response body when something goes wrong with my request and I am trying to use the @NotEmpty
constraint message attribute to return the error message,
This is my class that returns the error message using the body that I need:
package c.m.nanicolina.exceptions;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
@ControllerAdvice
public class CustomResponseEntityExceptionHandler {
@ExceptionHandler(value = {MissingServletRequestParameterException.class})
public ResponseEntity<ApiError> handleConflict(MissingServletRequestParameterException ex, WebRequest request) {
ApiError apiError = new ApiError(ex.getMessage(), ex.getMessage(), 1000);
return new ResponseEntity<ApiError>(apiError, null, HttpStatus.BAD_REQUEST);
}
}
With this CustomResponseEntityExceptionHandler
I can return my own response body in case of validation errors.
What I am trying now is to get the message from the validation constraints.
This is my controller with the NotEmpty
constraint:
package c.m.nanicolina.controllers;
import c.m.nanicolina.models.Product;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.validation.constraints.NotEmpty;
@RestController
public class MinimumStockController {
@RequestMapping(value = "/minimumstock")
public Product product(
@RequestParam(value = "product.sku") @NotEmpty(message = "Product.sku cannot be empty") String sku,
@RequestParam(value = "stock.branch.id") String branchID) {
return null;
}
}
In my exception, I can't find a way to get that message Product.sku cannot be empty
and show it in my error response.
I have also checked the class MissingServletRequestParameterException
and there is the method getMessage
which is returning the default message.
Yes it is doable & spring very well supports it. You are just missing some configuration to enable it in spring.
- Use Spring
@Validated
annotation to enable spring to validate controller- Handle
ConstraintViolationException
in yourControllerAdvice
to catch all failed validation messages.- Mark
required=false
in@RequestParam
, so it will not throw MissingServletRequestParameterException and rather move to next step of constraint validation.
@ControllerAdvice
public class CustomResponseEntityExceptionHandler {
@ExceptionHandler
public ResponseEntity<ApiError> handle(ConstraintViolationException exception) {
//you will get all javax failed validation, can be more than one
//so you can return the set of error messages or just the first message
String errorMessage = new ArrayList<>(exception.getConstraintViolations()).get(0).getMessage();
ApiError apiError = new ApiError(errorMessage, errorMessage, 1000);
return new ResponseEntity<ApiError>(apiError, null, HttpStatus.BAD_REQUEST);
}
}
@RestController
@Validated
public class MinimumStockController {
@RequestMapping(value = "/minimumstock")
public Product product(
@RequestParam(value = "product.sku", required=false) @NotEmpty(message = "Product.sku cannot be empty") String sku,
@RequestParam(value = "stock.branch.id", required=false) String branchID) {
return null;
}
}
NOTE: MissingServletRequestParameterException
won't have access to javax validation messages, as it is thrown before constraint validation occurs in the request lifecycle.