Ndtyjky

I have custom Filter and I want to log body from request.
But when I use ContentCachingRequestWrapper and try to call getContentAsByteArray() I always get an empty array.

@Component

public class CustomFilter implements Filter {



    private final Logger log = LoggerFactory.getLogger(CustomFilter.class);



    @Override

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {



        HttpServletRequest request = (HttpServletRequest) req;

        HttpServletResponse response = (HttpServletResponse) res;

        HttpServletRequest requestToCache = new ContentCachingRequestWrapper(request);



        chain.doFilter(req, res);



       log.info(getRequestData(requestToCache));

    }



    @Override

    public void init(FilterConfig filterConfig) {

    }



    @Override

    public void destroy() {

    }



    public static String getRequestData(final HttpServletRequest request) throws UnsupportedEncodingException {

        String payload = null;

        ContentCachingRequestWrapper wrapper = WebUtils.getNativeRequest(request, ContentCachingRequestWrapper.class);

        if (wrapper != null) {

            byte buf = wrapper.getContentAsByteArray();

            if (buf.length > 0) {

                payload = new String(buf, 0, buf.length, wrapper.getCharacterEncoding());

            }

        }

        return payload;

    }

  }

I also tried create Interceptor, but had the same problem.
What am I doing wrong?
Thanks for help.

You can use the existing spring implementation by just registering this bean in a @Configuration annotated class:

@Bean

public static Filter requestLoggingFilter() {

    final CommonsRequestLoggingFilter loggingFilter = new CommonsRequestLoggingFilter();

    loggingFilter.setIncludePayload(true);

    loggingFilter.setMaxPayloadLength(512);



    return loggingFilter;

}

Whilst I'd recommend going with NiVer's answer, I've been looking into why this issue occurs and I can finally give you an answer.

When you create a new ContentCachingRequestWrapper, the internal ByteArrayOutputStream is initialized but no data is copied to it. The body is only written to the ByteArrayOutputStream when you call getParameter, getParameterMap(), getParameterNames() or getParameterValues(String name) methods, and even then the data is only copied if the content type contains application/x-www-form-urlencoded.