Thread: Junit Test for exception and WebRequest

I'm a beginner and i'm writing unittests and I've stumbled across something I can't find a solution for that fits my needs.

I want to write some Junit Test for that exceptions.

There is my class with my Method ($ == at, i don't know why but the editor doesn't accept at):

$ControllerAdvice
$RestController
public class CustomizedResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {
 
    $ExceptionHandler(MethodArgumentTypeMismatchException.class)
    public final ResponseEntity<AccessError> numberFormatExceptionNotFoundException(
                MethodArgumentTypeMismatchException ex, NumberFormatException exe, WebRequest request) {
            AccessError errorDetails = new AccessError();
            errorDetails.code("400");
            errorDetails.addErrorsItem(new Error("400",ex.getMessage()));
            errorDetails.setCode("400");
            errorDetails.setTimestamp(new Date().toInstant().atOffset(ZoneOffset.UTC));
            errorDetails.setMessage(HttpStatus.BAD_REQUEST.getReasonPhrase());
            errorDetails.setPath(((ServletWebRequest) request).getRequest().getRequestURI());
            return new ResponseEntity<>(errorDetails, HttpStatus.BAD_REQUEST);
        }
    $Override
    protected ResponseEntity<Object> handleHttpMediaTypeNotSupported(HttpMediaTypeNotSupportedException ex,
            HttpHeaders headers, HttpStatus status, WebRequest request) {
        AccessError errorDetails = new AccessError();
        errorDetails.code("400");
        errorDetails.addErrorsItem(new Error("400","Media Type Not Supported Exception"));
        errorDetails.setCode("400");
        errorDetails.setTimestamp(new Date().toInstant().atOffset(ZoneOffset.UTC));
        errorDetails.setMessage(HttpStatus.BAD_REQUEST.getReasonPhrase());
        errorDetails.setPath(((ServletWebRequest) request).getRequest().getRequestURI());
        return new ResponseEntity<>(errorDetails, HttpStatus.BAD_REQUEST);
    }

And there is my testClass :

 
public class CustomizedResponseEntityExceptionHandlerTest {
$Mock
ResponseEntity<AccessError> responseEntity;
WebRequest webRequest;
 
$InjectMocks
private CustomizedResponseEntityExceptionHandler custom = new CustomizedResponseEntityExceptionHandler();
 
$Test
public void numberFormatExceptionNotFoundExceptionTest() {
 
    WebRequest webRequest;
    String msg = "test";
    AccessError errors = new AccessError();
    errors.setPath("app");
    errors.getPath();
    errors.setTimestamp(new Date().toInstant().atOffset(ZoneOffset.UTC));
    errors.timestamp(new Date().toInstant().atOffset(ZoneOffset.UTC));
    ApiException apiException = new ApiException(errors, msg);
 
    ResponseEntity<AccessError> responseApi = custom.handleUserNotFoundException(apiException, webRequest.getHeaderNames());
    assertThatExceptionOfType(ApiException.class);
 
}

My Question is : How i can do a JUnit Test for that cases, which have webRequest and some exceptions ?

I've tried a lot of thing but i think i don't have the right thinking method.

Thanks !!