code: @Override
      public void dumpRequest(Map<String, Object> result) {
          String contentType = exchange.getRequestHeaders().getFirst(Headers.CONTENT_TYPE);
          //only dump json info
          if (contentType != null && contentType.startsWith("application/json")) {
              //if body info already grab by body handler, get it from attachment directly
              Object requestBodyAttachment = exchange.getAttachment(BodyHandler.REQUEST_BODY);
              if(requestBodyAttachment != null) {
                  dumpBodyAttachment(requestBodyAttachment);
              } else {
                  //otherwise get it from input stream directly
                  dumpInputStream();
              }
          } else {
              logger.info("unsupported contentType: {}", contentType);
          }
          this.putDumpInfoTo(result);
      }
docs: impl of dumping request body to result
  @param result A map you want to put dump information to