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SLF4J: Class path contains multiple SLF4J bindings warning

I’ve seen in other questions that usually the solution to this warning is to exclude slf4j from the dependency that causes this conflict, but I can’t spot the problem in my project.

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/Applications/Eclipse.app/Contents/Eclipse/plugins/org.eclipse.m2e.maven.runtime.slf4j.simple_1.16.0.20200610-1735/jars/slf4j-simple-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [file:/Applications/Eclipse.app/Contents/Eclipse/configuration/org.eclipse.osgi/5/0/.cp/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.SimpleLoggerFactory]
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/Applications/Eclipse.app/Contents/Eclipse/plugins/org.eclipse.m2e.maven.runtime.slf4j.simple_1.16.0.20200610-1735/jars/slf4j-simple-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [file:/Applications/Eclipse.app/Contents/Eclipse/configuration/org.eclipse.osgi/5/0/.cp/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.SimpleLoggerFactory]

I run mvn dependency:tree command and this is the output:

[INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ subscriptionsmanager ---
[INFO] it.pietro:subscriptionsmanager:jar:0.0.1-SNAPSHOT
[INFO] +- junit:junit:jar:4.13.1:test
[INFO] |  - org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] +- org.mockito:mockito-core:jar:3.5.13:test
[INFO] |  +- net.bytebuddy:byte-buddy:jar:1.10.15:test
[INFO] |  +- net.bytebuddy:byte-buddy-agent:jar:1.10.15:test
[INFO] |  - org.objenesis:objenesis:jar:3.1:test
[INFO] +- org.mongodb:mongo-java-driver:jar:3.12.7:compile
[INFO] +- ch.qos.logback:logback-classic:jar:1.2.3:compile
[INFO] |  +- ch.qos.logback:logback-core:jar:1.2.3:compile
[INFO] |  - org.slf4j:slf4j-api:jar:1.7.25:compile
[INFO] +- de.bwaldvogel:mongo-java-server:jar:1.11.1:compile
[INFO] |  +- de.bwaldvogel:mongo-java-server-core:jar:1.11.1:compile
[INFO] |  |  +- io.netty:netty-transport:jar:4.1.31.Final:compile
[INFO] |  |  |  +- io.netty:netty-buffer:jar:4.1.31.Final:compile
[INFO] |  |  |  |  - io.netty:netty-common:jar:4.1.31.Final:compile
[INFO] |  |  |  - io.netty:netty-resolver:jar:4.1.31.Final:compile
[INFO] |  |  - io.netty:netty-codec:jar:4.1.31.Final:compile
[INFO] |  - de.bwaldvogel:mongo-java-server-memory-backend:jar:1.11.1:compile
[INFO] +- org.assertj:assertj-core:jar:3.15.0:test
[INFO] +- org.testcontainers:mongodb:jar:1.15.1:compile
[INFO] |  - org.testcontainers:testcontainers:jar:1.15.1:compile
[INFO] |     +- org.apache.commons:commons-compress:jar:1.20:compile
[INFO] |     +- org.rnorth.duct-tape:duct-tape:jar:1.0.8:compile
[INFO] |     +- org.rnorth.visible-assertions:visible-assertions:jar:2.1.2:compile
[INFO] |     |  - net.java.dev.jna:jna:jar:5.2.0:compile
[INFO] |     +- com.github.docker-java:docker-java-api:jar:3.2.7:compile
[INFO] |     |  - com.fasterxml.jackson.core:jackson-annotations:jar:2.10.3:compile
[INFO] |     - com.github.docker-java:docker-java-transport-zerodep:jar:3.2.7:compile
[INFO] |        - com.github.docker-java:docker-java-transport:jar:3.2.7:compile
[INFO] +- org.assertj:assertj-swing-junit:jar:3.17.1:test
[INFO] |  +- org.assertj:assertj-swing:jar:3.17.1:test
[INFO] |  |  - org.easytesting:fest-util:jar:1.2.5:test
[INFO] |  - org.easytesting:fest-reflect:jar:1.4.1:test
[INFO] - info.picocli:picocli:jar:4.5.2:compile

Answer

You can solve the issue by adding the following exclusion in the dependencies (of pom.xml) that caused conflict.

 <exclusions>
    <exclusion>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
    </exclusion>
 </exclusions> 
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