How to use custom logger to log access log in spring boot

Question

Currently in spring boot 1.3, we could only log access log to a file in the filesystem. Is there any way to actually use the custom logger (like log4j2) to log the access log?

I am currently using undertow with spring boot, but after checking the spring boot source code, the undertow logger is initialized with DefaultAccessLogReceiver which is writing to file. I would like to use the AccessLogHandler if possible, and avoid writing a web filter which logs the access.

Is there any easy way around this? (except writing a pull request)

Answer 1

A trick for this kind of hard-coded-thus-not-customizeable problem is to hide the class to kick out with a new one with the same package and name. All you have to do is to provide a log4j based DefaultAccessLogReceiver and make sure it can be search by the classloader before the one in the undertow library.

package io.undertow.server.handlers.accesslog;

public class DefaultAccessLogReceiver implements AccessLogReceiver {

    public void logMessage(final String message) {
        // TODO: log with log4j
    }
}