SLF4J: Class path contains multiple SLF4J bindings. Cant get rid of binding

Question

So,

once again im totally stuck with this error.. I've read few threads about the issue but cant fix it..

SLF4J: Found binding in [jar:file:/home/me/.m2/repository/org/apache/logging/log4j/log4j-slf4j-impl/2.10.0/log4j-slf4j-impl-2.10.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/me/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]

mvn dependency:tree gives following:

[INFO] +- org.springframework.boot:spring-boot-starter-data-jpa:jar:2.0.3.RELEASE:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter:jar:2.0.3.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot:jar:2.0.3.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-autoconfigure:jar:2.0.3.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-starter-logging:jar:2.0.3.RELEASE: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.apache.logging.log4j:log4j-to-slf4j:jar:2.10.0:compile

For what i understand one instance is under starter-data-jpa and in the folder .m2/ch/qos

but i cant delete that folder or the app wont start.

i cant seem to exclude it either.

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

After exclusion i run mvn clean and re-import all the dependecies but it still wont start.

And when i delete the whole

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

section, it now resides under [INFO] +- org.springframework.boot:spring-boot-starter-jdbc:jar:2.0.3.RELEASE:compile

according to mvn dependency:tree and app still wont start, same error.

So how do i get rid of this thing?

I have no idea how this happend. i have not added or removed anything in pom for weeks.

score 1 · Accepted Answer · answered Nov 28 '18 at 13:37

Decided to exclude all the logging framework so there wont be anymore unwanted loggers anywhere... it works

        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>

score 1 · Answer 2 · answered Jul 25 '19 at 14:16

This problem exists from a long time. The best way to deal with this is to follow the steps:

Look for maven dependencies. Search for log4j-slf4j. This library can be from multiple dependencies. I didn't want to remove spring-boot-starter-logging as it effects regular pretty spring logs. How to get a dependency tree for an artifact?.

mvn dependency:tree

Exclude the dependency. You must be able to find one or more dependencies which has the same library. I had slf4j-log4j12 only in kafka-avro-serializer so I excluded from it. If your mvn dependency tree shows more thatn one make sure you exclude from all.

   <dependency>
        <groupId>io.confluent</groupId>
        <artifactId>kafka-avro-serializer</artifactId>
        <version>4.0.0</version>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

SLF4J: Class path contains multiple SLF4J bindings. Cant get rid of binding

2 Answers2