Play logback doesnt work when explicit logback dependency is on classpath

Play Framework
1

I need to have explicit dependency on logback during uberbuild to avoid issue at runtime conflicting with log4j. However when I do this play logback play.api.Logger stops working. It’s happening for standalone non-mvc app where play logback is used.

2

its a dreaded “conflicting slf4j binding found on classpath” issue. off topic, but runtime found both slf4j-log4j12 and logback on classpath. something might have introduced some dependency that brought log4j in picture.

3

Yes indeed. Lots of libraries depend upon that, and need to be excluded. Some of my dependencies

  "org.apache.hadoop" % "hadoop-common" % "2.7.2" exclude("org.slf4j", "slf4j-log4j12"),
  "org.apache.hadoop" % "hadoop-hdfs" % "2.7.2" exclude("org.slf4j", "slf4j-log4j12"),
  "org.cassandraunit" % "cassandra-unit" % "2.1.3.1" exclude("org.slf4j", "slf4j-log4j12")

Have used GitHub - sbt/sbt-dependency-graph: sbt plugin to create a dependency graph for your project in the past for getting the dependency tree, but surely newer sbt may have some native integration to view dependency tree too.

Regards
Aditya

4

You can also use https://github.com/cb372/sbt-explicit-dependencies to show the explicit dependencies of each library.