How to override HttpServletRequest toString method?

Question

I'm using Servlet based web application and want to have proper logging support. I'm using Log4j and when I do receive any requests I want to log it with it's whole properties (not everything, just headers and parameters).

For example:

@WebServlet(name = "Login", value = "/Login")
public class Login extends HttpServlet {
    final static Logger logger = Logger.getLogger(Login.class);

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        logger.info(req); // I want to log request with its 
        // properties: such as request parameters, headers and so on
        // TODO some logic here
    }
}

So, how can I mange to override somehow HttpServletRequests toString() method which actually is an interface. Is it good idea to create Wrapper class for it and can override toString() method there?

Well, to override HttpServletRequest's toString() method, you need to extend/implement it. Why do you even want to? — Chris Neve, Mar 29 '19 at 09:38
you probably want an interceptor and some library where this is already done — Eugene, Mar 29 '19 at 09:38
@ChrisNeve I need to log requests parameters into my logging file to see details of each one. — Mikheil Zhghenti, Mar 29 '19 at 09:40
@Eugene Could you please give me an example? Actually, I'm not using Spring for this project. — Mikheil Zhghenti, Mar 29 '19 at 09:41
@ChrisNeve Could you please tell me what would be the best practice for my problem? — Mikheil Zhghenti, Mar 29 '19 at 09:42
HttpServletRequest probably does have a toString() method, but it's going to contain far too much information. Just use logger.info(...) on whatever property you're interested in, for example, logger.info(req.getMethod()) — Chris Neve, Mar 29 '19 at 09:51
@ChrisNeve In this case to use HttpServletRequest's toString() method is not very useful, because it just prints it's pointer and doesn't provide any "meta data". — Mikheil Zhghenti, Mar 29 '19 at 09:55
You can refer to this post. https://stackoverflow.com/questions/6631257/how-to-log-properly-http-requests-with-spring-mvc — Yi Zhao, Mar 29 '19 at 10:10

score 1 · Answer 1 · answered Mar 29 '19 at 09:55

1

You can implement a Filter like this and you can get all request headers and paramters and you can logged into your file

@Component
public class HttpFilter implements Filter {
private static final Logger LOGGER = LogManager.getLogger(HttpLogging.class);

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain 
chain)
        throws IOException, ServletException {
    // TODO Auto-generated method stub

    HttpServletRequest httpServletRequest  = (HttpServletRequest) request;
    HttpServletResponse httpServletResponse  = (HttpServletResponse)response;
    LOGGER.info("logger before method aop FROM FILTER CLASS");
    LOGGER.info("content type " + httpServletRequest.getContentType());
    LOGGER.info("Local Name" + httpServletRequest.getLocalName());
      LOGGER.info("content type " + httpServletRequest.getContentType());
         LOGGER.info("request uri " +  httpServletRequest.getRequestURI());
         LOGGER.info("get Method " + httpServletRequest.getMethod());
         LOGGER.info("query string "  +httpServletRequest.getQueryString() );
         LOGGER.info("server name " + httpServletRequest.getServerName());
         LOGGER.info("server port "  + httpServletRequest.getServerPort());
         LOGGER.info("Parameter names  " + httpServletRequest.getParameter("empid"));


    System.out.println(request.getContentType());

    chain.doFilter(httpServletRequest, httpServletResponse);





  }

}

answered Mar 29 '19 at 09:55

Aakash Khatavkar

111
1
15

I do believe that this is not called the best practice. – Mikheil Zhghenti Mar 29 '19 at 09:57
So, the question is tha how can I override toString() method once and then this method will be called whenever I try to log it into my file. – Mikheil Zhghenti Mar 29 '19 at 09:59
This is the best practise, before calling your Servlet filter gets called for your each request and while sending response it will send through filter only. – Aakash Khatavkar Mar 29 '19 at 10:00
So, you mean that for each servlet I need to override doFilter() method and copy/paste the same flow if I need to logged all request in a same style ? – Mikheil Zhghenti Mar 29 '19 at 10:02
If your job is to log each and every request then why you need to overide toString() method ?? It's just use to print you current object – Aakash Khatavkar Mar 29 '19 at 10:02
not for each Servlet. When ever request will come to any servlet it will pass through filter. suppose you are having 5 servlet then it will be only 1 filter for all 5 servlet. – Aakash Khatavkar Mar 29 '19 at 10:04
Could you provide your web.xml ? – Mikheil Zhghenti Mar 29 '19 at 11:03
my project is build in spring boot so no web.xml file – Aakash Khatavkar Mar 29 '19 at 11:12
Yes, I noticed you used @Component. – Mikheil Zhghenti Mar 29 '19 at 11:15

score 1 · Answer 2 · answered Mar 29 '19 at 18:54

Here's what I've used in the past. It uses SLF4J but the statements should be nearly identical to Log4J.

import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class RequestLogger {

    public static void logRequestAttributes(Logger logger, HttpServletRequest request) {
        logger.debug("Attributes:");
        for (Enumeration<?> attributeNames = request.getAttributeNames(); attributeNames.hasMoreElements(); ) {
            String nextAttributeName = (String) attributeNames.nextElement();

            logger.debug("attribute \"" + nextAttributeName + "\" value is \"" + request.getAttribute(nextAttributeName) + "\"");
        }

        logger.debug("Parameters:");
        for (Enumeration<?> parameterNames = request.getParameterNames(); parameterNames.hasMoreElements(); ) {
            String nextParameterName = (String) parameterNames.nextElement();

            logger.debug("parameter \"" + nextParameterName + "\" value is \"" + request.getParameter(nextParameterName) + "\"");
        }

        logger.debug("Headers:");
        for (Enumeration<?> e = request.getHeaderNames(); e.hasMoreElements(); ) {
            String nextHeaderName = (String) e.nextElement();

            logger.debug("header name: \"" + nextHeaderName + "\" value is \"" + request.getHeader(nextHeaderName) + "\"");
        }

        String logStatement = "Server Name: " + request.getServerName() + "\n";
        logStatement += "\tServer Port: " + request.getServerPort() + "\n";
        logStatement += "\tServlet Path: " + request.getServletPath() + "\n";
        logStatement += "\tMethod: " + request.getMethod() + "\n";
        logStatement += "\tPath info: " + request.getPathInfo() + "\n";
        logStatement += "\tPath translated: " + request.getPathTranslated() + "\n";
        logStatement += "\tRequest URI: " + request.getRequestURI() + "\n";
        logStatement += "\tRequest URL: " + request.getRequestURL() + "\n";
        logStatement += "\tQuery String: " + request.getQueryString() + "\n";
        logStatement += "\tContext path: " + request.getContextPath() + "\n";

        logger.debug(logStatement);
    }
}

How to override HttpServletRequest toString method?

2 Answers2