Prevent Tomcat from overriding error response returned by controller advice

Question

I have implemented a RestControllerAdvice for handling exception in Spring Boot-Tomcat Web application as shown below :

@RestControllerAdvice 
public class ExceptionHandlerRest{
 private Logger logger=LoggerFactory.getLogger(getClass());

 @ExceptionHandler(Exception.class)
 public ResponseEntity<?> handleException(Exception ex){
  logger.error("System Error", ex);
  SimpleResponse=new SimpleResponse(ex.getMessage(),"Error code 001"));
  return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(response);
 }

}

So whenever a web request results into exception i am expecting above handler to return status 500 and a json having content : "{"technicalMessage" : "NullPointerException","userMessage":"Error Code 001"}

However,instead of that a html error page is coming printing entire stack trace as shown below :

the SimpleResponse has below definition :

public class SimpleResponse{
   String technicalMessage,userMessage;

   //public getters and setters


}

I have put debug point and observed that code flow does reach properly to return statement of handleException of RestControllerAdvice. I think some how tomcat is ignoring my response and showing exception stack trace. How can i make my application return error message in a json ?

Yes i am sure . I debugged and control is coming to exception handler and properly returning POJO response but some how tomcat is ignoring it and showing default error page — Goro
Is this on an embedded Tomcat or on an external one? (PS. I noticed your last paragraph that's why I deleted my original comment. ) — g00glen00b
I can't reproduce this with the code you provided, so I guess the error is elsewhere. What is BaseScreeningException? Is this being thrown within your exception handler? — g00glen00b
It is being thrown by rest controller when it sees some bad request — Goro

Goro Goro · Accepted Answer · 2018-06-20T10:31:00

I could resolve the issue. This issue was happening for rest controller which annotated with @RequestMapping(produces=MediaType.application_pdf_value). Some how when error was throw and was received by error handler, the POJO was not getting converted to JSON due to produces attribute of actual controller. I removed the produces attribute and instead set content type explicitly into response. Now both scenarios are working fine, downloading of pdf or exception message display.

Prevent Tomcat from overriding error response returned by controller advice

1 Answers