~~NOTRANS~~
~~Title: Use log4j~~

This is a very technical article and it's only relevant for developers or experienced users. Usually the integrated log mechanism is good enough, but from a developer point of view it might be helpful to use a different log mechanism.

Every application will be created with a **loggerfactory.properties** in the **test** directory. If you keep the file in the test directory, your application won't use customized logging after installation/deployment. If you want to use customized logging for the installed/deployed application, just move the file to the **src.server** folder. To configure log4j, simply remove the **#** from the first line. It will look like

<code>
default.class=com.sibvisions.util.log.log4j.Log4jLoggerFactory
</code>
afterwards.

Also create a [[jvx:common:util:log4j|log4j.properties]] or [[jvx:common:util:log4j|log4j2.xml]] in the **src.server** folder.

This was the configuration part, now you need the log4j libraries. Please download:

  * [[https://repo1.maven.org/maven2/org/apache/logging/log4j/log4j-1.2-api/2.25.0/log4j-1.2-api-2.25.0.jar|log4j api bridge (2.25.0)]]
  * [[https://repo1.maven.org/maven2/org/apache/logging/log4j/log4j-api/2.25.0/log4j-api-2.25.0.jar|log4j 2 api (2.25.0)]]
  * [[https://repo1.maven.org/maven2/org/apache/logging/log4j/log4j-core/2.25.0/log4j-core-2.25.0.jar|log4j 2 core 2.25.0)]]

and put all into the **libs/server** directory. 

If you run your application in Eclipse or any other IDE, be sure to add all 3 libraries to your build path (classpath) and also as Deployment Assemlbies.