如何从 Spring Boot 的 ExceptionHandler 中的请求中获取正文数据？

Question

I have a @RestControllerAdvice where I handle an Exception in Spring Boot. I would like to log an information that is sent through request body. How can I get this information from a spring WebRequest?

This is my sample exception handler.

@RestControllerAdvice
public class CustomExceptionHandler extends ResponseEntityExceptionHandler {

@Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex,
        HttpHeaders headers, HttpStatus status, WebRequest request) {

    // I want to add something here that I could log an info that is in the request body.
    return super.handleMethodArgumentNotValid(ex, headers, status, request);
}

}

@M.Deinum I tried to use ContentCachingRequestWrapper, But I could not have acess to body content. The method contentCachingRequestWrapper.getContentAsByteArray() returns null.

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
      throws IOException, ServletException {

    try {
        ContentCachingRequestWrapper wrappedRequest = new ContentCachingRequestWrapper((HttpServletRequest) request);
        wrappedRequest.getContentAsByteArray();
        wrappedRequest.getInputStream();
        chain.doFilter(wrappedRequest, response);
    } finally {
        LoggingContext.clear();
    }

Answer 1

The comments regarding using the ContentCachingRequestWrapper are accurate, this is the implementation using your controller advice that should work.

@Component
public class MyFilter implements Filter {
  @Override
  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
  throws IOException, ServletException {
     ContentCachingRequestWrapper contentCachingRequestWrapper = new ContentCachingRequestWrapper(
    (HttpServletRequest) servletRequest);

     filterChain.doFilter(contentCachingRequestWrapper, servletResponse);
  }
}

The advice

@RestControllerAdvice
public class CustomExceptionHandler extends ResponseEntityExceptionHandler {

  @Override
  protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers,
  HttpStatus status, WebRequest request) {

    ContentCachingRequestWrapper nativeRequest = (ContentCachingRequestWrapper) ((ServletWebRequest) request).getNativeRequest();
    String requestEntityAsString = new String(nativeRequest.getContentAsByteArray());

    log.debug(requestEntityAsString);

    return super.handleMethodArgumentNotValid(ex, headers, status, request);
  }
}

Answer 2

RequestBody and ResponseBody can be read-only once so other ways to achieve the body in the exception handler Visit here