How do I customize default error message from spring #Valid validation? - json

Question

DTO:
public class User {
#NotNull
private String name;
#NotNull
private String password;
//..
}
Controller:
#RequestMapping(value = "/user", method = RequestMethod.POST)
public ResponseEntity<String> saveUser(#Valid #RequestBody User user) {
//..
return new ResponseEntity<>(HttpStatus.OK);
}
Default json error:
{"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.User> demo.UserController.saveUser(demo.User), with 2 error(s): [Field error in object 'user' on field 'name': rejected value [null]; codes [NotNull.user.name,NotNull.name,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.name,name]; arguments []; default message [name]]; default message [may not be null]],"path":"/user"}
I would like to have my custom json for each error occured. How do I accomplish that?

Answer 1

If you want full control over the response message in every controller write a ControllerAdvice. For example, that example transform MethodArgumentNotValidException into a custom json object:
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import java.util.ArrayList;
import java.util.List;
import static org.springframework.http.HttpStatus.BAD_REQUEST;
/**
* Kudos http://www.petrikainulainen.net/programming/spring-framework/spring-from-the-trenches-adding-validation-to-a-rest-api/
*
*/
#Order(Ordered.HIGHEST_PRECEDENCE)
#ControllerAdvice
public class MethodArgumentNotValidExceptionHandler {
#ResponseStatus(BAD_REQUEST)
#ResponseBody
#ExceptionHandler(MethodArgumentNotValidException.class)
public Error methodArgumentNotValidException(MethodArgumentNotValidException ex) {
BindingResult result = ex.getBindingResult();
List<org.springframework.validation.FieldError> fieldErrors = result.getFieldErrors();
return processFieldErrors(fieldErrors);
}
private Error processFieldErrors(List<org.springframework.validation.FieldError> fieldErrors) {
Error error = new Error(BAD_REQUEST.value(), "validation error");
for (org.springframework.validation.FieldError fieldError: fieldErrors) {
error.addFieldError(fieldError.getField(), fieldError.getDefaultMessage());
}
return error;
}
static class Error {
private final int status;
private final String message;
private List<FieldError> fieldErrors = new ArrayList<>();
Error(int status, String message) {
this.status = status;
this.message = message;
}
public int getStatus() {
return status;
}
public String getMessage() {
return message;
}
public void addFieldError(String path, String message) {
FieldError error = new FieldError(path, message);
fieldErrors.add(error);
}
public List<FieldError> getFieldErrors() {
return fieldErrors;
}
}
}

Answer 2

You can perform validation with Errors/BindingResult object.
Add Errors argument to your controller method and customize the error message when errors found.
Below is the sample example, errors.hasErrors() returns true when validation is failed.
#RequestMapping(value = "/user", method = RequestMethod.POST)
#ResponseBody
public ResponseEntity<String> saveUser(#Valid #RequestBody User user, Errors errors) {
if (errors.hasErrors()) {
return new ResponseEntity(new ApiErrors(errors), HttpStatus.BAD_REQUEST);
}
return new ResponseEntity<>(HttpStatus.OK);
}

Answer 3

I know this is kind of old question,
But I just run into it and I found some pretty good article which has also a perfect example in github.
Basically it uses #ControllerAdvice as Spring documentation suggests.
So for example catching 400 error will be achieved by overriding one function:
#ControllerAdvice
public class CustomRestExceptionHandler extends ResponseEntityExceptionHandler {
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(final MethodArgumentNotValidException ex, final HttpHeaders headers, final HttpStatus status, final WebRequest request) {
logger.info(ex.getClass().getName());
//
final List<String> errors = new ArrayList<String>();
for (final FieldError error : ex.getBindingResult().getFieldErrors()) {
errors.add(error.getField() + ": " + error.getDefaultMessage());
}
for (final ObjectError error : ex.getBindingResult().getGlobalErrors()) {
errors.add(error.getObjectName() + ": " + error.getDefaultMessage());
}
final ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST, ex.getLocalizedMessage(), errors);
return handleExceptionInternal(ex, apiError, headers, apiError.getStatus(), request);
}
}
(ApiError class is a simple object to hold status, message, errors)

Answer 4

One way to do it is adding message in #NotNull annotation on entity properties. And adding #Valid annotation in controller request body.
DTO:
public class User {
#NotNull(message = "User name cannot be empty")
private String name;
#NotNull(message = "Password cannot be empty")
private String password;
//..
}
Controller:
#RequestMapping(value = "/user", method = RequestMethod.POST)
public ResponseEntity<String> saveUser(#Valid #RequestBody User user) {
//..
return new ResponseEntity<>(HttpStatus.OK);
}
// Add one
#ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<List<YourErrorResponse>> handleException(MethodArgumentNotValidException ex) {
// Loop through FieldErrors in ex.getBindingResult();
// return *YourErrorReponse* filled using *fieldErrors*
}

Answer 5

#ControllerAdvice(annotations = RestController.class)
public class GlobalExceptionHandler implements ApplicationContextAware {
#ExceptionHandler(MethodArgumentNotValidException.class)
#ResponseStatus(HttpStatus.OK)
#ResponseBody
public ApplicationError validationException(MethodArgumentNotValidException e) {
e.printStackTrace();
return new ApplicationError(SysMessageEnum.MSG_005, e.getBindingResult().getAllErrors().get(0).getDefaultMessage());
}
}

Answer 6

You can do something like this
#ExceptionHandler(value = MethodArgumentNotValidException.class)
protected ResponseEntity<Error> handleGlobalExceptions(MethodArgumentNotValidException ex,
WebRequest request) {
log.catching(ex);
return new ResponseEntity<>(createErrorResp(HttpStatus.BAD_REQUEST,
ex.getBindingResult().getFieldErrors().stream().map(err -> err.getDefaultMessage())
.collect(java.util.stream.Collectors.joining(", "))),
HttpStatus.BAD_REQUEST);
}

Answer 7

For customized the error message in JSON format then do the below steps.
- Create one #Component called CommonErrorHandler
#Component
public class CommonErrorHandler {
public Map<String,Object> getFieldErrorResponse(BindingResult result){
Map<String, Object> fielderror = new HashMap<>();
List<FieldError>errors= result.getFieldErrors();
for (FieldError error : errors) {
fielderror.put(error.getField(), error.getDefaultMessage());
}return fielderror;
}
public ResponseEntity<Object> fieldErrorResponse(String message,Object fieldError){
Map<String, Object> map = new HashMap<>();
map.put("isSuccess", false);
map.put("data", null);
map.put("status", HttpStatus.BAD_REQUEST);
map.put("message", message);
map.put("timeStamp", DateUtils.getSysDate());
map.put("filedError", fieldError);
return new ResponseEntity<Object>(map,HttpStatus.BAD_REQUEST);
}
}
-- Add InvalidException class
public class InvalidDataException extends RuntimeException {
/**
* #author Ashok Parmar
*/
private static final long serialVersionUID = -4164793146536667139L;
private BindingResult result;
public InvalidDataException(BindingResult result) {
super();
this.setResult(result);
}
public BindingResult getResult() {
return result;
}
public void setResult(BindingResult result) {
this.result = result;
}
}
- Introduce #ControllerAdvice class
#ControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler(InvalidDataException.class)
public ResponseEntity<?> invalidDataException(InvalidDataException ex, WebRequest request) {
List<FieldError> errors = ex.getResult().getFieldErrors();
for (FieldError error : errors) {
logger.error("Filed Name ::: " + error.getField() + "Error Message :::" + error.getDefaultMessage());
}
return commonErrorHandler.fieldErrorResponse("Error", commonErrorHandler.getFieldErrorResponse(ex.getResult()));
}
}
-- Use in controller with #Valid and throw exception
public AnyBeans update(**#Valid** #RequestBody AnyBeans anyBeans ,
BindingResult result) {
AnyBeans resultStr = null;
if (result.hasErrors()) {
**throw new InvalidDataException(result);**
} else {
resultStr = anyBeansService.(anyBeans );
return resultStr;
}
}
-- Output will be in JSON format
{
"timeStamp": 1590500231932,
"data": null,
"message": "Error",
"isSuccess": false,
"status": "BAD_REQUEST",
"filedError": {
"name": "Name is mandatory"
}
}
Hope this will be work. :-D

Answer 8

#ControllerAdvice
#RestController
public class CustomizedResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(
MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
// ex.getBindingResult(): extract the bind result for default message.
String errorResult = ex.getBindingResult().toString();
CustomizedExceptionHandlerResponse exceptionResponse = new CustomizedExceptionHandlerResponse(
errorResult, new Date(), request.getDescription(false));
return new ResponseEntity<>(exceptionResponse, HttpStatus.BAD_REQUEST);
}
}
class CustomizedExceptionHandlerResponse {
private String message;
private String status;
private Date timestamp;
// constuctor, setters, getters...
}

Answer 9

you can use this code to iterate through errors and build a custom error message :
import lombok.Data;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import javax.validation.ConstraintViolation;
import java.util.List;
import java.util.stream.Collectors;
#ControllerAdvice
public class ExceptionHandlerController {
#ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<ErrorDto> handleException(MethodArgumentNotValidException ex) {
ErrorDto dto = new ErrorDto(HttpStatus.BAD_REQUEST, "Validation error");
dto.setDetailedMessages(ex.getBindingResult().getAllErrors().stream()
.map(err -> err.unwrap(ConstraintViolation.class))
.map(err -> String.format("'%s' %s", err.getPropertyPath(), err.getMessage()))
.collect(Collectors.toList()));
return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(dto);
}
#Data
public static class ErrorDto {
private final int status;
private final String error;
private final String message;
private List<String> detailedMessages;
public ErrorDto(HttpStatus httpStatus, String message) {
status = httpStatus.value();
error = httpStatus.getReasonPhrase();
this.message = message;
}
}
}
This will give you a response like this in case of error :
{
"status": 400,
"error": "Bad Request",
"message": "Validation error",
"detailedMessages": [
"'yourField' should not be empty."
]
}

Answer 10

Add some information too.
If you use just #Valid, you need to catch BindException. If you use #Valid #RequestBody catch MethodArgumentNotValidException
Some sources:
HandlerMethodArgumentResolverComposite.getArgumentResolver(MethodParameter parameter):129 - search which HandlerMethodArgumentResolver support such parameter
RequestResponseBodyMethodProcessor.supportsParameter(MethodParameter parameter) - return true if parameter has annotation #RequestBody
RequestResponseBodyMethodProcessor:139 - throw MethodArgumentNotValidException
ModelAttributeMethodProcessor:164 - throw BindException

Answer 11

I know this is an old question, but i stumbled across and decided to show a cleaner way of doing what Ksokol showed.
StandardError class:
#Data
#AllArgsConstructor
#NoArgsConstructor
public class StandardError {
private Instant timestamp;
private Integer status;
private String error;
private String message;
private String path;
}
ControllerExceptionHandler class:
#ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<StandardError> notValid(MethodArgumentNotValidException e, HttpServletRequest request) {
String error = "Dados inválidos.";
HttpStatus status = HttpStatus.UNPROCESSABLE_ENTITY;
StandardError err = new StandardError(
Instant.now(),
status.value(),
error,
e.getBindingResult()
.getFieldErrors()
.stream()
.map(FieldError::getDefaultMessage)
.collect(Collectors.toSet())
.toString()
.replaceAll("\\[*]*", ""),
request.getRequestURI()
);
return ResponseEntity.status(status).body(err);
}
This way if you have a custom message on your bean validator, it will appear formatted in a error.
Result: