Apache Log4j is a versatile, industrial-grade Java logging framework composed of an API, its implementation, and components to assist the deployment for various use cases.

You can manually download all published Log4j distributions, verify them, and see their licensing information by following the instructions in the Download page of Logging Services.

Apache Log4j is a versatile, industrial-grade Java logging framework composed of an API, its implementation, and components to assist the deployment for various use cases.

Apache Log4j 2 is an upgrade to Log4j that provides significant improvements over its predecessor, Log4j 1.x, and provides many of the improvements available in Logback while …

Log4j is essentially composed of a logging API called Log4j API, and its reference implementation called Log4j Core. Log4j also bundles several logging bridges to enable Log4j Core consume …

The table below contains links to the Javadoc API Documentation for the components you are most likely to use directly in code.

This page tries to cover the most prominent Log4j API features. Did you know that Log4j provides specialized APIs for Kotlin and Scala? Check out Log4j Kotlin and Log4j Scala projects for …

Log4j Core uses plugins to inject necessary components while reading a configuration file. In this section, we will explore extension points users can hook into to customize the way Log4j Core …

The JUL-to-Log4j API and Log4j 1-to-Log4j API will no longer be able to modify the configuration of Log4j Core by default. If such a functionality is required, it must be explicitly enabled.

The Log4j Core implementation fully supports both standard and custom levels. Similarly to the Log4j API usage, custom levels must be defined in a configuration file before they can be used.