Instead of writing your own classes to cache request response for logging, Spring provides a couple of useful classes i.e. ContentCachingRequestWrapper and ContentCachingResponseWrapper. These classes can be utilized very effectively, for example, in the following little filter:

LoggingFilter.java

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Date;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.util.ContentCachingRequestWrapper;
import org.springframework.web.util.ContentCachingResponseWrapper;
import org.springframework.web.util.WebUtils;

@Component
public class LoggingFilter implements Filter {

    private static final Logger LOG = LoggerFactory.getLogger(LoggingFilter.class);

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

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

        if (servletRequest instanceof HttpServletRequest
            && servletResponse instanceof HttpServletResponse) {
            HttpServletRequest request = (HttpServletRequest) servletRequest;
            HttpServletResponse response = (HttpServletResponse) servletResponse;

            HttpServletRequest requestToCache = new ContentCachingRequestWrapper(request);
            HttpServletResponse responseToCache = new ContentCachingResponseWrapper(response);
            chain.doFilter(requestToCache, responseToCache);
            String requestData = getRequestData(requestToCache);
            String responseData = getResponseData(responseToCache);
        } else {
            chain.doFilter(servletRequest, servletResponse);
        }
    }

    private 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;
    }

    private static String getResponseData(final HttpServletResponse response) throws IOException {
        String payload = null;
        ContentCachingResponseWrapper wrapper =
            WebUtils.getNativeResponse(response, ContentCachingResponseWrapper.class);
        if (wrapper != null) {
            byte[] buf = wrapper.getContentAsByteArray();
            if (buf.length > 0) {
                payload = new String(buf, 0, buf.length, wrapper.getCharacterEncoding());
                wrapper.copyBodyToResponse();
            }
        }
        return payload;
    }  

    @Override
    public void destroy() {
    }
}

Hello guys, I tried the same but still giving me null in both requestData and responseData