SLF4J: Class path contains multiple SLF4J bindings; exclude slf4j

Question

I am trying to load a Video using OpenIMAJ. It does Display the Video but always shows me this Error:

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/MaryLu/.m2/repository/ch/qos/logback/logback-classic/1.0.0/logback-classic-1.0.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/MaryLu/.m2/repository/org/slf4j/slf4j-log4j12/1.7.2/slf4j-log4j12-1.7.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [ch.qos.logback.classic.selector.DefaultContextSelector]
16/04/24 20:39:57 INFO xuggle.XuggleVideo: URL file:/F:/workspaceMaven/keyboardcat.flv could not be opened by ffmpeg. Trying to open a stream to the URL instead.
20:39:57.984 [main] DEBUG com.xuggle.xuggler - Could not open output url: file:/F:/workspaceMaven/keyboardcat.flv (../../../../../../../csrc/com/xuggle/xuggler/Container.cpp:436)

I already checked Similar Questions but I didn't manage to solve the problem. If i understood, i need to exclude slf4j somewhere in my POM.xml but i don't really know in which dependency.

Answer 1

The slf4j messages is just telling you that your slf4j configuration is broken so it falls back to a default configuration.

The real problem is that your URL does not point to a local file as you apparently expect it to because it is broken, so the code trying to use it fails. A possible reason for the brokenness might be if you have the file open already somewhere, so Windows will not allow it to be overwritten.

Answer 2

Already the answer is given in your log file. Follow the tutorial.

http://www.slf4j.org/codes.html#multiple_bindings

As Wouter stated

Run mvn dependency:tree and search which dependency have the slf4j implementations you do not want, then exclude them with a dependency exclusion like:

<dependency>
    <groupId>org.someexternallib</groupId>
    <artifactId>someexternallibartifact</artifactId>
    <version>...</version>

    <exclusions>
       <exclusion> 
          <groupId>org.slf4j</groupId>
          <artifactId>slf4j-log4j12</artifactId>
       </exclusion>
       <exclusion> 
          <groupId>log4j</groupId>
          <artifactId>log4j</artifactId>
      </exclusion>
    </exclusions> 
</dependency>

Answer 3

          <exclusion>
            <artifactId>logback-classic</artifactId>
            <groupId>ch.qos.logback</groupId>
          </exclusion>

          <exclusion>
                <artifactId>slf4j-simple</artifactId>
                <groupId>org.slf4j</groupId>
            </exclusion>

In order to find the dependencies that use above artifact, find out by "$ mvn dependency:tree" once you find that out put the above exclusions on the corresponding dependencies. That should fix it, I would say pay attention on specific dependencies.