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# Log4j to SLF4J Adapter

The Log4j 2 to SLF4J Adapter allows applications coded to the Log4j 2 API to be routed to SLF4J.
Use of this adapter may cause some loss of performance as the Log4j 2 Messages must be formatted
before they can be passed to SLF4J. With Log4j 2 as the implementation these would normally be
formatted only when they are accessed by a Filter or Appender.

## Requirements

The Log4j 2 to SLF4J adapter is dependent on the Log4j 2 API and the SLF4J API.
For more information, see [Runtime Dependencies](runtime-dependencies.html).

## Usage

Include this jar, the SLF4J jar(s) and an SLF4J logging implementation jar together. Configure
the logging implementation as required.

<div class="alert alert-danger">
Use of the SLF4J adapter (log4j-to-slf4j-2.x.jar) together with
the SLF4J bridge (log4j-slf4j-impl-2.x.jar) should
never be attempted as it will cause events to endlessly be routed between
SLF4J and Log4j 2.
</div>
