Chainsaw Home Page

Author: Oliver Burn
Hosted by: SourceForge Logo


Chainsaw has been contributed to the Log4J package. It is available as part of the standard distribution since release 1.2 of Log4J. All future enhancements will be made against this branch of Chainsaw. Only download this version if you need to run against Log4J 1.1.3.

13-May-2002 - Oliver


Chainsaw is a GUI log viewer and filter for the Log4J package. By default it listens for LoggingEvent objects sent using the SocketAppender and displays them in a table. The events can be filtered based on:

All the details for each event can be displayed by selecting the event in the table.

Chainsaw also supports loading a events logged to a file using the XMLLayout format. This is great for analysing log files, and means you do not need to keep Chainsaw running all the time! It is easy to add support for loading events from other sources like JDBC.

A picture tells a thousand words, so click here for a screen shot.

Screen shot of chainsaw.

Finally, why is it called chainsaw? Because it cuts your log (file) down to size. :-)

Getting chainsaw.

Binary and source distributions are from SourceForge. The project home page is at

system requirements

To run chainsaw you will need:

To build chainsaw you will need:

Running chainsaw


You need to include the following JARs in the classpath:

  1. chainsaw-1.1.jar
  2. log4j.jar


The command line usage is:

  java -D<property>=<value>

The default behaviour of chainsaw can be changed by setting system properties using the -D<property>=<value> arguments to java. The following table describes what properties can be set:

Property Description
chainsaw.port Indicates which port to listen for connections on. Defaults to "4445".

Configuring Log4J

You will need to configure Log4J to send logging events to Chainsaw and a file. Here is a sample file for sending logging events to a file in XML format and Chainsaw.

log4j.rootCategory=DEBUG, Default, Chainsaw



// chainsaw: GUI viewer and filter for Log4J.
// Copyright (C) 2001-2002  Oliver Burn
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// Lesser General Public License for more details.
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


If you have any feedback on this tool, please email me at I am interested in any improvements you would like to see (or hopefully made!).

Also, send me email if you would like to be notified when a newer version of chainsaw is released.

Copyright © 2001-2002 Oliver Burn. All rights Reserved.