Answer by Reto Weiss

Reto Weiss — Tue, 02 Oct 2018 09:38:28 -0400

Hi Peter

You could use the following Utility class to forward log message from one Logger to another one. E.e. from the Hibernate Logger to the Runtime Log (ivy.log)

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Priority;
import org.apache.log4j.spi.LoggingEvent;

import ch.ivyteam.ivy.environment.Ivy;
import ch.ivyteam.log.Logger;

public class LogUtil
{
    private static class ForwardAppender extends AppenderSkeleton 
    {
        public static final String NAME = ForwardAppender.class.getSimpleName();
        private Logger to;

        @SuppressWarnings("deprecation")
        public ForwardAppender(Logger to) {
            this.to = to;
            setName(NAME);
        }

        @Override
        public void close() {
        }

        @Override
        public boolean requiresLayout() {
            return false;
        }

        @Override
        protected void append(LoggingEvent event) {
            if (event.getThrowableInformation() != null)
            {
                to.log(event.getLevel(), event.getMessage(), event.getThrowableInformation().getThrowable());
            }
            else
            {
                to.log(event.getLevel(), event.getMessage());
            }
        }
    }

    public static void forwardLoggerToLogger(Logger from, Logger to)
    {
        if (from.getAppender(ForwardAppender.NAME)==null)
        {
            from.addAppender(new ForwardAppender(to));
        }
    }

    public static void main(String[] args) 
    {
        // Example 
        Logger hibernate = Logger.getLogger("org.hibernate");
        Logger runtimeLog = Ivy.log();
        forwardLoggerToLogger(hibernate, runtimeLog);
    }
}

Answers to: Display log4j Messages in Runtime Log

Answer by Reto Weiss