Use case:
There is a need to use some existing custom Java code in a BE application. This code makes use of the slf4j libraries for logging messages.  How can these messages be logged to our BE application log file?

How to bridge the sl4j and log4j logging mechanisms in BE 5.6 and 6.1.

Follow the steps below:

1. Disable the default BE logging configuration. In the CDD editor in Studio, go to the 'Collections' tab, and select logConfig'.  In the configuration options, un-check the 'Enable' checkbox.  This will disable the default logging configuration, which you must now replace with a custom logging configuration. Note that a logging configuration is already provided in your BE installation under %BE_HOME%/lib/ext/tpcl/apache/. 

2. Although you may edit the BE-provided logging configuration in-place, it is recommended that you instead specify the path to your custom logging configuration in your project's CDD file under the 'Cluster' tab. Add the cluster-level property as follows (note the property name and path syntax is different, depending on your BE version):

• For BE 5.6: log4j.configuration=file:C:/logconfigs/log4j.xml
• For BE 6.1: log4j.configurationFile=file:///C:/logconfigs/log4j2.xml

3. For BE 5.6, no further configuration is needed, as the necessary slf4j-log4j bridge is already provided in your installation under %BE_HOME%/lib/ext/tpcl/slf4j-log4j12-1.7.28.jar. For BE 6.1, you will need to obtain the updated binding for log4j v2 from Maven Central:

4.  Add the log4j-slf4j-impl-2.0.2.jar to the front of the classpath. You can do this with the 'tibco.env.CUSTOM_EXT_PREPEND_CP' property in your BE engine TRA file:
       
  tibco.env.CUSTOM_EXT_PREPEND_CP=C:/jars/log4j-slf4j-impl-2.0.2.jar

You are now configured to emit slf4j logging messages via log4j.