Java/Spring: Override default @RequestBody functionality

Question

So I have this API:

public Map<String, Object> myFunc(@RequestBody @Valid MyPrivateEntity body) {}

Which is marked with @RequestBody and @Valid

The thing is, if I omit the body when calling this API, I get the following error message:

{
"title": "Failed to parse request",
"detail": "Required request body is missing: public com.privatePackage.misc.service.rest.MyPrivateEntity com.privatePackage.misc.service.rest.MyPrivateResource.myFunc(java.lang.String, com.privatePackage.misc.service.rest.MyPrivateEntity)",
"status": 400

}

I don't want the error message to include class names and paths, instead just "Required request body is missing".

How can I do that?

Thanks

Answer 1

Try this code

@ExceptionHandler(BindException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)  // return 400 if validate fail
public String handleBindException(BindException e) {
    // return message of first error
    String errorMessage = "Request not found";
    if (e.getBindingResult().hasErrors())
        e.getBindingResult().getAllErrors().get(0).getDefaultMessage();
    return errorMessage;
}

Or use this way

public Map<String, Object> myFunc(
        @RequestBody @Valid MyPrivateEntity body,
        BindingResult bindingResult) {  // add this parameter
    // When there is a BindingResult, the error is temporarily ignored for manual handling
    // If there is an error, block it
    if (bindingResult.hasErrors())
        throw new Exception("...");

}

Reference: https://www.baeldung.com/spring-boot-bean-validation

Answer 2

If you need more control on only this endpoint then I'll suggest to mark request body optional and check in the method if it's null then return whatever message you want to show.

@RequestBody(required = false)

Answer 3

Try @ControllerAdvice to customise your message.

@ControllerAdvice
        public class RestExceptionHandler extends ResponseEntityExceptionHandler {
    
            @Override
            protected ResponseEntity<Object> handleHttpMessageNotReadable(
                HttpMessageNotReadableException ex, HttpHeaders headers,
                HttpStatus status, WebRequest request) {
                // paste custom hadling here
            }
        }

Reference:

https://ittutorialpoint.com/spring-rest-handling-empty-request-body-400-bad-request/