in log4j I could specify a class in the properties file to log at the debug level like this:
log4j.logger.com.mycompany.mypackage.ClassName=DEBUG
As the log4j2 configuration documentation states
As of version 2.4, Log4j now supports configuration via properties files. Note that the property syntax is NOT the same as the syntax used in Log4j 1.
It then provides a substantial example for all types of configuration elements.
Concerning your question, you need to specify your loggers in a loggers
element, then configure each of them. For example
loggers = mine
logger.mine.name = com.mycompany.mypackage.ClassName
logger.mine.level = DEBUG
Note that log4j2 looks for a .properties file on the classpath by default.
If a test file cannot be located the properties ConfigurationFactory will look for
log4j2.properties
on the classpath.
But you can also configure the location yourself. You can use the system property
-Dlog4j.configurationFile=conf/log4j.properties
with an appropriate path.