sbt exclusion slf4j not working

Question

I have a third party dependency in my play project. That third party library has eventual dependency ( not direct ) on an slf4j implementation.

I am getting duplicate binding error for slf4j.

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:~/.ivy2/cache/ch.qos.logback/logback-classic/jars/logback-classic-1.1.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/~/.ivy2/cache/com.orgname.platform/platform-logging-client/jars/platform-logging-client-2.5.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]

I tried following things but can get rid of the error.

"com.orgname.platform" % "platform-metric-client" % "1.0.4" excludeAll(
    ExclusionRule(organization = "org.slf4j"))

I also tried following exclusion

"com.orgname.platform" % "platform-metric-client" % "1.0.4" exclude("org.slf4j","slf4j-jdk14)

and also this one

 "com.orgname.platform" % "platform-metric-client" % "1.0.4" exclude("org.slf4j","slf4j-log4j12)

Since I was not able to remove the slf4j from third party dependency I, tired to remove the play dependency on slf4j, by modifying projcts/plugin.sbt

addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.4.6" exclude("org.slf4j", "slf4j-simple"))

How should I go about getting rid of this warning. how does this warning impact the logging? Which logging implementation would be used the Scala implementation?

Answer 1

The answer by YourBestBet is correct, but you can save yourself some copy-pasting by mapping the sequence of imports with the excludes.

//dependencies with exclusions
libraryDependencies ++= Seq(
    //depencies
).map(_.exclude("org.slf4j", "*"))

//insert one without exclusion
libraryDependencies ++= Seq(
  "ch.qos.logback" % "logback-classic" % "1.1.3"
)

EDIT:

I suggest investing some time and understanding transitive dependencies and scope management. It will save you time in the future. Maven has a great and straightforward doc page about it: https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html

PS. Exclude? Provided?

Answer 2

IMHO, No matter exclude or excludeAll , it only excludes slf4j dependency from THAT library, not excluding slf4j dependency from the whole project. Thus, all library dependencies lines which may transitively depend on slf4j need to add exclude("org.slf4j","slf4j-log4j12).

A quick and dirty solution is to append exclude("org.slf4j","slf4j-log4j12) to each libraryDepencies line. I tried this, it worked for me.