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:

• Level
• Thread name
• Logger
• Message
• NDC

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 continously. It is easy to add support for loading events from other sources like JDBC.

A picture is worth a thousand words:

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

Requirements

Chainsaw is based on the Swing API which requires JDK 1.2 or later.

Running chainsaw

Setup

You need to include the log4j.jar in the classpath.

Usage

The command line usage is:

  java -D<property>=<value> org.apache.log4j.chainsaw.Main 

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:

Configuring Log4J

You will need to configure log4j to send logging events to Chainsaw. Here is a sample log4j.properties file for sending logging events to Chainsaw.

log4j.rootLogger=DEBUG, CHAINSAW_CLIENT

log4j.appender.CHAINSAW_CLIENT=org.apache.log4j.net.SocketAppender
log4j.appender.CHAINSAW_CLIENT.RemoteHost=localhost
log4j.appender.CHAINSAW_CLIENT.Port=4445
log4j.appender.CHAINSAW_CLIENT.LocationInfo=true