Most modules in SSM depend on Hadoop jars which further depend on log4j. And we also used log4j in our own SSM code. To upgrade it, we excluded 1.2.17 dependencies and introduced 2.17.0 dependencies. And to let the code calling old version of log4j still work, we also introduced another dependency called log4j-1.2-api (2.17.0 version). With such handling, dependency issue can be avoided. And a setting is also required to tell 2.17.0 version of log4j to find its configuration file, which is different from 1.x versions.
Most modules in SSM depend on Hadoop jars which further depend on log4j. And we also used log4j in our own SSM code. To upgrade it, we excluded 1.2.17 dependencies and introduced 2.17.0 dependencies. And to let the code calling old version of log4j still work, we also introduced another dependency called log4j-1.2-api (2.17.0 version). With such handling, dependency issue can be avoided. And a setting is also required to tell 2.17.0 version of log4j to find its configuration file, which is different from 1.x versions.