Trying to get Spring Boot app to send an error response message when request does not have "Con-CodePudding

I am still really new with Spring Boot, but I have a web application, that is setup to handle either XML requests (when the requests have a "Content-type: application/xml" header, or JSON requests (when the requests have a "Content-type: application/xml" header), and I noticed that if the "Content-type" header is either missing, or contains something other than "Content-type: application/xml" or "Content-type: application/json", I get a "415" response error code. The logging also shows a message like:

.w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/x-www-form-urlencoded' not supported]

I found this older SO thread:

Springboot exception handler doesn't catch exception

and have been trying to implement the code that was posted by "Sannu" on Dec 17 '16 at 13:55. This is the code that I built and am testing (as a test, I was trying to change the error response code to "500" and also have a error response message):

import org.apache.logging.log4j.LogManager;

import org.springframework.http.ResponseEntity;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver;

import mil.nga.geoaxis.pdp.models.ErrorResponse;

import org.springframework.http.HttpStatus;


@ControllerAdvice  
public class SpringExceptionHandler extends ExceptionHandlerExceptionResolver
{
    @ExceptionHandler(org.springframework.web.HttpMediaTypeNotSupportedException.class)
    public ResponseEntity<Object>     handleControllerException(HttpMediaTypeNotSupportedException ex, WebRequest req)
{
    ErrorResponse errorResponse = null;
    //ex.printStackTrace();
    errorResponse = new ErrorResponse();
    errorResponse.setCode(HttpCodes.HTTP_CODE_INTERNAL_ERROR);
    System.out.println("In SpringExceptionHandler.handleControllerException: HttpStatus.INTERNAL_SERVER_ERROR.value()=["   HttpStatus.INTERNAL_SERVER_ERROR.value()   "]");
    System.out.println("In SpringExceptionHandler.handleControllerException: ex.getMessage()=["   ex.getMessage()   "]");
    int myCode = errorResponse.getCode();
    System.out.println("In SpringExceptionHandler.handleControllerException: errorResponse.getCode()/String.valueOf(myCode)=["   String.valueOf(myCode)   "]");

    
    errorResponse.setCode(HttpStatus.INTERNAL_SERVER_ERROR.value());
    errorResponse.setMessage(ex.getMessage());

    myCode = errorResponse.getCode();
    System.out.println("In SpringExceptionHandler.handleControllerException: errorResponse.getCode()/String.valueOf(myCode)=["   String.valueOf(myCode)   "]");

    return new ResponseEntity<Object>(errorResponse, HttpStatus.valueOf(errorResponse.getCode()));
    
}
}

However, when I test, and send a request with no "Content-type:" header (using curl), I am still getting what appears to be a response with "100" response code, then a response with a "415" response code, and no response message.

FYI, here is part of the logging that is appearing:

In SpringExceptionHandler.handleControllerException: HttpStatus.INTERNAL_SERVER_ERROR.value()=[500]
In SpringExceptionHandler.handleControllerException: ex.getMessage()=[Content type 'application/x-www-form-urlencoded' not supported]
In SpringExceptionHandler.handleControllerException: errorResponse.getCode()/String.valueOf(myCode)=[0]
In SpringExceptionHandler.handleControllerException: errorResponse.getCode()/String.valueOf(myCode)=[500]
WARN 15428 --- [io-18443-exec-1] .m.m.a.ExceptionHandlerExceptionResolver : Failure in @ExceptionHandler      ....errorhandling.SpringExceptionHandler#handleControllerException(HttpMediaTypeNotSupportedException, WebRequest)

Can anyone suggest why this does not seem to be able to send the error code and response message?

[FYI, I am doing this under Spring Boot 2.5.6.]

Thanks in advance!

Jim

EDIT 1: I modified the class per huy's suggestion to this:

import org.apache.logging.log4j.LogManager;

import org.springframework.http.ResponseEntity;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver;



@ControllerAdvice  
public class SpringExceptionHandler 
{
    @ExceptionHandler(org.springframework.web.HttpMediaTypeNotSupportedException.class)
public ResponseEntity handleControllerException(HttpMediaTypeNotSupportedException ex, WebRequest req)
{
    ErrorResponse errorResponse = null;
    //ex.printStackTrace();
    errorResponse = new ErrorResponse();
    //errorResponse.setCode(HttpCodes.HTTP_CODE_INTERNAL_ERROR);
    System.out.println("In SpringExceptionHandler.handleControllerException: HttpStatus.INTERNAL_SERVER_ERROR.value()=["   HttpStatus.INTERNAL_SERVER_ERROR.value()   "]");
    System.out.println("In SpringExceptionHandler.handleControllerException: ex.getMessage()=["   ex.getMessage()   "]");
    int myCode = errorResponse.getCode();
    System.out.println("In SpringExceptionHandler.handleControllerException: errorResponse.getCode()/String.valueOf(myCode)=["   String.valueOf(myCode)   "]");

    
    errorResponse.setCode(HttpStatus.INTERNAL_SERVER_ERROR.value());
    errorResponse.setMessage(ex.getMessage());

    myCode = errorResponse.getCode();
    System.out.println("In SpringExceptionHandler.handleControllerException: errorResponse.getCode()/String.valueOf(myCode)=["   String.valueOf(myCode)   "]");

    return ResponseEntity
            .status(HttpStatus.valueOf(415))
            .body(ex.getMessage());
    
}
}

The code above causes a response with error code 415, and the text error message from the HttpMediaTypeNotSupportedException exception.

CodePudding user response：

You don't need to extend ExceptionHandlerException..., it's used by default to resolve error.

You only need only ControllerAdvice and ExceptionHandler, ExceptionHandlerExceptionResolver will auto scan annotation ExceptionHandler and handle it.