spring request body caching

23 November 2019

ContentCachingRequestWrapper와 ContentCachingResponseWrapper를 사용해서 request body와 response body를 여러번 접근해 log에 남겨보도록 하겠습니다.
먼저 아래와 같이 requestfilter를 정의해줍니다.


@Component
@Slf4j
public class RequestFilter extends GenericFilterBean {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        ContentCachingRequestWrapper requestWrapper = new ContentCachingRequestWrapper((HttpServletRequest) request);
        ContentCachingResponseWrapper responseWrapper = new ContentCachingResponseWrapper((HttpServletResponse) response);

        chain.doFilter(requestWrapper, responseWrapper);

        log.info("\n[{}]{} - {}\nHeaders : {}\nRequest : {}Response : {}",
                ((HttpServletRequest) request).getMethod(),
                ((HttpServletRequest) request).getRequestURI(),
                responseWrapper.getStatus(),
                getHeaders((HttpServletRequest) request),
                getRequestBody(requestWrapper),
                getResponseBody(responseWrapper));
    }

    private Map getHeaders(HttpServletRequest request) {
        Map headerMap = new HashMap<>();

        Enumeration headerArray = request.getHeaderNames();
        while (headerArray.hasMoreElements()) {
            String headerName = headerArray.nextElement();
            headerMap.put(headerName, request.getHeader(headerName));
        }
        return headerMap;
    }

    private String getRequestBody(ContentCachingRequestWrapper request) {
        ContentCachingRequestWrapper wrapper = WebUtils.getNativeRequest(request, ContentCachingRequestWrapper.class);
        if (wrapper != null) {
            byte[] buf = wrapper.getContentAsByteArray();
            if (buf.length > 0) {
                try {
                    return new String(buf, 0, buf.length, wrapper.getCharacterEncoding());
                } catch (UnsupportedEncodingException e) {
                    return "";
                }
            }
        }
        return "";
    }

    private String getResponseBody(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;
    }
}

그리고 아래와 같이 filter를 등록해주도록 합니다.

 @Bean
    public FilterRegistrationBean registrationBean(HttpServletRequest httpServletRequest) {
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        registrationBean.setFilter(new RequestFilter());
        return registrationBean;
    }

아래와 같이 로그로 남겨지는 것을 확인할 수 있습니다.

[POST]/ - 200
Headers : {content-length=17, host=localhost:8080, connection=keep-alive, content-type=application/json, accept-encoding=gzip, deflate, user-agent=HTTPie/1.0.3, accept=application/json, */*}
Request : {"name":"value"}
Response : {"response":"value"}