LF5 User Guide

Log4j Project

LogFactor5 Overview

What is LogFactor5? - LogFactor5 is a Swing based GUI that leverages the power of log4j logging framework and provides developers with a sophisticated, feature-rich, logging interface for managing log messages.

How does it work? - LogFactor5 seamlessly plugs into log4j and provides developers with an alternate destination for outputting messages.


  • Quickly isolate problems in your application.
  • Enable only the categories that you are interested in without affecting other messages.
  • Filter out priority levels you don't need.
  • Filter out records based on NDC.
  • Reduce the time required to locate specific messages.
  • Read in and view log4j log files from either a file or a URL.
  • Start the LogFactor5 GUI up independent of your application.


  • Real-time category and log level filtering.
  • Read log files from a file.
  • Read log files from a URL.
  • Customizable Log Table view.
  • Category level tree navigation.
  • NDC record filtering.
  • Full text searching on logged messages.
  • Save configuration and filtering settings for later sessions.
  • Configure the number of log records to be displayed.
  • Customizable record colors.
  • Configurable font face and size.
  • Customizable Log Table column layout.
  • Full support for all log4j levels.
  • Full support for custom levels.
  • Dynamic message counting.

LogFactor5 System Requirements:

LogFactor5 requires Java (TM) Virtual Machine 1.2.2 and log4j 1.2 or later.

Documentation and Help

  • All documentation is in HTML format.
  • For additional documentation on logging, please see the Suggested Reading section.

Platform Support

  • LogFactor5 is written in 100% Java and will work with any system supporting the Java 2 platform.

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