Springboot exception handler doesn't catch exception

Question

In Spring boot and rest application, i have configured a exception handler as following. It works fine if an exception is thrown after request makes it to rest service.

The Rest api expects Content-Type of "application/json" and If I do not send that content-type header to the api, exception handler does not catch the exception. It prints following information in the log:

DEBUG [o.s.w.s.DispatcherServlet] DispatcherServlet with name 'dispatcherServlet' processing PUT request for [/app/v1.0/customers/customer/zones/zoneName.]
DEBUG [o.s.w.s.m.m.a.RequestMappingHandlerMapping] Looking up handler method for path /app/v1.0/customers/customer/zones/zoneName.
DEBUG [o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver] Resolving exception from handler [null]: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain' not supported
DEBUG [o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver] Invoking @ExceptionHandler method: public final org.springframework.http.ResponseEntity<java.lang.Object> org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler.handleException(java.lang.Exception,org.springframework.web.context.request.WebRequest)
DEBUG [o.s.w.s.DispatcherServlet] Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
DEBUG [o.s.w.s.DispatcherServlet] Successfully completed request

Here's the exception handler class:

@ControllerAdvice
@RestController  
public class ServiceExceptionHandler extends ResponseEntityExceptionHandler
{

    @ExceptionHandler(Exception.class)  
    public final ResponseEntity<java.lang.Object> handleException(Throwable ex,WebRequest req)
    {
        ErrorResponse errorResponse = null;
        if (ex instanceof ApiException)
        {
            errorResponse = new ErrorResponse((ApiException) ex);
        }
        else
        {
            logger.error(ex);
            errorResponse = new ErrorResponse();
            errorResponse.setCode(HttpCodes.HTTP_CODE_500);
            errorResponse.setError(ex.getMessage());
        }
        return new ResponseEntity<Object>(errorResponse,
                HttpStatus.valueOf(errorResponse.getCode()));

    }
    protected ResponseEntity<Object> handleNoHandlerFoundException(NoHandlerFoundException ex,
            HttpHeaders headers, HttpStatus status, WebRequest request)
    {
        Map<String, String> responseBody = new HashMap<String, String>();
        responseBody.put("path", request.getContextPath());
        responseBody.put("message",
                "The URL you have reached is not in service at this time (404).");
        return new ResponseEntity<Object>(responseBody, HttpStatus.NOT_FOUND);
    }
}

Answer 1

Your class will only catch errors raised from within a controller. The error you are seeing occurs before a controller is invoked, as Spring cannot find a controller to handle the request.

DEBUG [o.s.w.s.m.m.a.RequestMappingHandlerMapping] Looking up handler method for path /app/v1.0/customers/customer/zones/zoneName.
DEBUG [o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver] Resolving exception from handler [null]: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain' not supported

Notice the handler is null.

You will also need to implement a HandlerExceptionResolver to handle that type of exception: http://docs.spring.io/spring/docs/3.1.x/spring-framework-reference/html/mvc.html#mvc-exceptionhandlers

See Spring exception handler outside controller for more details.