Logging all API call traffic in Java servlets

We have a few servlets like the one below, taking JSON request and produce JSON response. And the requirement is to log all API call traffic.

import org.slf4j.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class CommentServlet {
  private static final Logger LOG = LoggerFactory.getLogger(CommentServlet.class);
  public void postComment(HttpServletRequest request, HttpServletResponse response) throws IOException {
    String commentRequested = request.getParameter("comment");
    LOG.info(commentRequested);
    Object postResultModel = processComment(commentRequested);
    JsonUtil.writeResponse(response, postResultModel);
  }
  /**
  * doesn't reallty matter what processComment does
  */
  public Object processComment(String comment) {
    return new Object();
  }
}

import org.slf4j.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;
public class JsonUtil {
    private static final Logger LOG = LoggerFactory.getLogger(JsonUtil.class);
    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
    public static void writeResponse(HttpServletResponse response, Object modelObject) throws IOException {
        String modelJson = OBJECT_MAPPER.writeValueAsString(modelObject);
        LOG.info(modelJson);
        response.setContentType("application/json");
        response.getWriter().write(modelJson);
    }
}

if you can mainly review how the logging is done, I'd like feedback on the general approach as much as whether there's any way to improve it.