CODEWITHSUNDEEP
javaspringspring-bootkotlin
sankar
sankar

Reputation: 278

Spring Boot add Request Body in the Error Response Entity

I have my own Exceptionhandler which is extending ResponseEntityExceptionHandler

I am able to capture the error but the request body is empty at the time of error response creation

override fun handleHttpMessageNotReadable(e:HttpMessageNotReadableException, headers:HttpHeaders , status:HttpStatus , webRequest: WebRequest):ResponseEntity<Any>{
        val rsp = ErrResponse(
                Data(
                        HttpStatus.BAD_REQUEST.name,
                        e.message!!
                ),**REQUEST-BODY-NEEDED**[customFilter.payload])
        return super.handleExceptionInternal(e, rsp,headers, HttpStatus.BAD_REQUEST, webRequest)
    }

So i have used customRequestfilter to get the body and captured the body there but the order precendence is low for customRequestFilter it will be get executed only after the request . So is there a any way to Capture the request body on the error response?

CustomRequestFilter

@Component
public class CustomRequestFilter extends OncePerRequestFilter{

 public String payload;
    public Map<String, Object> reqLog =null;
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
            throws ServletException, IOException {
        ContentCachingRequestWrapper wrappedRequest = new ContentCachingRequestWrapper(request);

        int status = HttpStatus.BAD_REQUEST.value();

        filterChain.doFilter(wrappedRequest, response);
        if (status == response.getStatus()) {
            reqLog = getTrace(wrappedRequest, status);
            payload = getBody(wrappedRequest, reqLog);/** ITS CAPTURING THE BODY HERE SUCCESSFULLY**/
            logTrace(wrappedRequest, reqLog); 
        }

    }

Upvotes: 1

Views: 2685

Answers (1)

LppEdd
LppEdd

Reputation: 21134

Wow, that was tricky! Anyway...

Create your custom HttpInputMessage, which will delegate to the original one.

class CachedHttpInputMessage implements HttpInputMessage {
    private final HttpInputMessage httpInputMessage;
    private ByteArrayOutputStream outputStream;

    CachedHttpInputMessage(final HttpInputMessage httpInputMessage) {
        this.httpInputMessage = httpInputMessage;
    }

    @Override
    public InputStream getBody() throws IOException {
        if (outputStream == null) {
            outputStream = new ByteArrayOutputStream();

            final InputStream body = httpInputMessage.getBody();
            final byte[] buffer = new byte[1024];

            while (true) {
                final int length;
                if (!((length = body.read(buffer)) > -1)) {
                    break;
                }

                outputStream.write(buffer, 0, length);
            }

            outputStream.flush();
        }

        return new ByteArrayInputStream(outputStream.toByteArray());
    }

    @Override
    public HttpHeaders getHeaders() {
        return httpInputMessage.getHeaders();
    }
}

Build your custom HttpMessageConverter, extending the right one based on the currently used one (Jackson, Gson, etc.), and register it as first.

class CustomHttpMessageConverter extends MappingJackson2HttpMessageConverter {
    @Override
    public Object read(
            final Type type,
            final Class<?> contextClass,
            final HttpInputMessage inputMessage) throws IOException {
        return super.read(type, contextClass, new CachedHttpInputMessage(inputMessage));
    }

    @Override
    protected Object readInternal(
            final Class<?> clazz,
            final HttpInputMessage inputMessage) throws IOException {
        return super.readInternal(clazz, new CachedHttpInputMessage(inputMessage));
    }
}

(alternatively you could create a generic wrapper, like with the CachedHttpInputMessage, and wrap each pre-configured HttpMessageConverter, just update the list passed as input to extendMessageConverters)

@Configuration
class WebConfiguration implements WebMvcConfigurer {
    @Override
    public void extendMessageConverters(final List<HttpMessageConverter<?>> converters) {
        converters.add(0, new CustomHttpMessageConverter());
    }

    ...
 }

Throw away the custom Filter, and inside the ExceptionHandler read the body using

final HttpInputMessage inputMessage = e.getHttpInputMessage();
final InputStream body = inputMessage.getBody();

Done!
Remember to clean-up the code a bit and handle all the possible exceptions.

Upvotes: 2

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