title: ERROR SLF4J: Class path contains multiple SLF4J bindings jenkins cobertura maven
body: <p>I'm with this error on third day already and I can't resolved. There is something that I can't grasp on and no matter what I do the error still persists.</p>
  
  <p>I'm reading a book called "Jenkins a definitive guide" (<a href="http://www.wakaleo.com/books/jenkins-the-definitive-guide" rel="noreferrer">http://www.wakaleo.com/books/jenkins-the-definitive-guide</a>) and I'm stuck on chapter two. Basically is a example of how to use Jenkins with Javadoc, JUnit and Cobertura plugin for Jenkins. Everything works until I get to Cobertura plugin part, where I get next error:</p>
  
  <pre><code>[ERROR] SLF4J: Class path contains multiple SLF4J bindings.
  SLF4J: Found binding in [jar:file:/C:/Windows/System32/config/systemprofile/.m2/repository/ch/qos/logback/logback-classic/1.0.13/logback-classic-1.0.13.jar!/org/slf4j/impl/StaticLoggerBinder.class]
  SLF4J: Found binding in [jar:file:/C:/Windows/System32/config/systemprofile/.m2/repository/org/slf4j/slf4j-simple/1.6.1/slf4j-simple-1.6.1.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.util.ContextSelectorStaticBinder]
  </code></pre>
  
  <p>I have seen other problems like mine and the conclusion I got is that I have either to include o exclude a dependency in my pom.xml file/s (this examples only uses pom files at this stage). My pom.xml file that has <em>slf4j-simple</em> looks like this:</p>
  
  <pre><code>&lt;project&gt;
  ......
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
              &lt;artifactId&gt;slf4j-simple&lt;/artifactId&gt;
              &lt;version&gt;1.6.1&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
              &lt;artifactId&gt;slf4j-api&lt;/artifactId&gt;
              &lt;version&gt;1.6.1&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p>and there is no explicit dependency to <em>logback-classic</em> hence I don't know in what dependency is being used. I tried to use dependency plugin for jenkins and I got this result:</p>
  
  <pre><code>[INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ gameoflife-web ---
  [INFO] com.wakaleo.gameoflife:gameoflife-web:war:1.0-SNAPSHOT
  [INFO] +- com.wakaleo.gameoflife:gameoflife-core:jar:1.0-SNAPSHOT:compile
  [INFO] +- org.springframework:spring-webmvc:jar:3.0.2.RELEASE:compile
  [INFO] |  +- org.springframework:spring-asm:jar:3.0.2.RELEASE:compile
  [INFO] |  +- org.springframework:spring-beans:jar:3.0.2.RELEASE:compile
  [INFO] |  +- org.springframework:spring-context:jar:3.0.2.RELEASE:compile
  [INFO] |  |  \- org.springframework:spring-aop:jar:3.0.2.RELEASE:compile
  [INFO] |  +- org.springframework:spring-context-support:jar:3.0.2.RELEASE:compile
  [INFO] |  \- org.springframework:spring-expression:jar:3.0.2.RELEASE:compile
  [INFO] +- org.springframework:spring-core:jar:3.0.2.RELEASE:compile
  [INFO] |  \- commons-logging:commons-logging:jar:1.1.1:compile
  [INFO] +- org.springframework:spring-web:jar:3.0.2.RELEASE:compile
  [INFO] |  \- aopalliance:aopalliance:jar:1.0:compile
  [INFO] +- javax.servlet:jstl:jar:1.2:compile
  [INFO] +- javax.servlet:servlet-api:jar:2.5:provided
  [INFO] +- org.mockito:mockito-all:jar:1.8.5:test
  [INFO] +- org.easytesting:fest-assert:jar:1.4:compile
  [INFO] |  \- org.easytesting:fest-util:jar:1.1.6:compile
  [INFO] +- org.slf4j:slf4j-simple:jar:1.6.1:compile
  [INFO] +- org.slf4j:slf4j-api:jar:1.6.1:compile
  [INFO] +- junit:junit:jar:4.11:test
  [INFO] |  \- org.hamcrest:hamcrest-core:jar:1.3:test
  [INFO] \- org.hamcrest:hamcrest-all:jar:1.1:test
  </code></pre>
  
  <p>Maybe I'm blind, but I still can't see who uses <em>logback-classic</em> (by the way I'm not sure what values are correct for <em></em> and <em></em> for <em>logback-classic</em>).
  I tried to remove the <em>slf4j</em> dependency's and I error is gone, but I don't get any cobertura reports. I tried to exclude <em>logback-classic</em> with </p>
  
  <pre><code>    &lt;dependency&gt;
          &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
          &lt;artifactId&gt;slf4j-simple&lt;/artifactId&gt;
          &lt;version&gt;1.6.1&lt;/version&gt;
          &lt;exclusions&gt;
              &lt;exclusion&gt;
                  &lt;groupId&gt;ch.qos.logback&lt;/groupId&gt;
                  &lt;artifactId&gt;logback-classic&lt;/artifactId&gt;
              &lt;/exclusion&gt;
          &lt;/exclusions&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
          &lt;artifactId&gt;slf4j-api&lt;/artifactId&gt;
          &lt;version&gt;1.6.1&lt;/version&gt;
          &lt;exclusions&gt;
              &lt;exclusion&gt;
                  &lt;groupId&gt;ch.qos.logback&lt;/groupId&gt;
                  &lt;artifactId&gt;logback-classic&lt;/artifactId&gt;
              &lt;/exclusion&gt;
          &lt;/exclusions&gt;
      &lt;/dependency&gt;
  </code></pre>
  
  <p>and the error persists. 
  I don't know what to do anymore, please help!</p>