@RestControllerAdvice that returns an object but handles errors from a void controller method does not return json

[geoand]

A simple way to reproduce this error is to change the existing spring-web integration to use :

    @GetMapping("/responseEntity")
    public Greeting handledByResponseEntity() {
        throw new IllegalStateException("bad state");
    }

to:

    @GetMapping("/responseEntity")
    public void handledByResponseEntity() {
        throw new IllegalStateException("bad state");
    }

in the ExceptionThrowingController class