Multiple bindings of SLF4J
<p>I have the following error in spring boot application:</p>

<p>SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/opt/tomcat/webapps/ROOT/WEB-INF/lib/slf4j-simple-1.7.13.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/opt/tomcat/webapps/ROOT/WEB-INF/lib/logback-classic-1.1.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See <a href="http://www.slf4j.org/codes.html#multiple_bindings" rel="nofollow">http://www.slf4j.org/codes.html#multiple_bindings</a> for an explanation.</p>

<p>I went to the link and tried to remove slf4j-simple-1.7.13 and logback-classic from the pom I thought was importing this but it did not work.</p>

<pre><code>    &lt;dependency&gt;
        &lt;groupId&gt;org.apache.solr&lt;/groupId&gt;
        &lt;artifactId&gt;solr-solrj&lt;/artifactId&gt;
        &lt;version&gt;${solrj.version}&lt;/version&gt;
        &lt;exclusions&gt;
            &lt;exclusion&gt;
                &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
                &lt;artifactId&gt;slf4j-api&lt;/artifactId&gt;
            &lt;/exclusion&gt;
        &lt;/exclusions&gt;
    &lt;/dependency&gt;
</code></pre>

<p>and </p>

<pre><code>    &lt;dependency&gt;
        &lt;groupId&gt;org.apache.solr&lt;/groupId&gt;
        &lt;artifactId&gt;solr-solrj&lt;/artifactId&gt;
        &lt;version&gt;${solrj.version}&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>Solr J version:</p>

<pre><code>    &lt;solrj.version&gt;5.2.1&lt;/solrj.version&gt;
</code></pre>

<p>How can I determine if this is the correct offending module? Is there something I'm doing incorrectly?</p>

<p>The pom file uses a spring boot parent we created ourselves. Maybe that is where the exclusions need to take place?</p>

<p>Here is the dependency tree for org.slf4j:</p>

<pre><code>[INFO] 
[INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ some-service ---
[INFO] com.company.io.some.service:some-service:war:1.0.0-SNAPSHOT
[INFO] +- com.company.io.commons:commons-mongo:jar:1.0.0:compile
[INFO] |  \- com.company.io.commons:discovery-schema:jar:1.0.0:compile
[INFO] |     +- com.company.io.commons:commons-schema:jar:1.0.0:compile
[INFO] |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.6; omitted for duplicate)
[INFO] |     +- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO] |     +- ch.qos.logback:logback-classic:jar:1.1.3:compile
[INFO] |     |  \- (org.com.company.io:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO] |     \- com.company.io.commons:commons-utils:jar:1.0.0:compile
[INFO] |        \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.6; omitted for duplicate)
[INFO] +- org.apache.solr:solr-solrj:jar:5.2.1:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:1.7.13:compile
[INFO] +- de.flapdoodle.embed:de.flapdoodle.embed.mongo:jar:1.50.5:test
[INFO] |  \- de.flapdoodle.embed:de.flapdoodle.embed.process:jar:1.50.2:test
[INFO] |     \- (org.slf4j:slf4j-api:jar:1.7.13:test - version managed from 1.7.10; omitted for duplicate)
[INFO] +- org.springframework.boot:spring-boot-starter-actuator:jar:1.3.0.RELEASE:compile
[INFO] |  \- org.springframework.boot:spring-boot-starter:jar:1.3.0.RELEASE:compile
[INFO] |     \- org.springframework.boot:spring-boot-starter-logging:jar:1.3.0.RELEASE:compile
[INFO] |        +- org.slf4j:jcl-over-slf4j:jar:1.7.13:compile
[INFO] |        |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.10; omitted for duplicate)
[INFO] |        +- org.slf4j:jul-to-slf4j:jar:1.7.13:compile
[INFO] |        |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.10; omitted for duplicate)
[INFO] |        \- org.slf4j:log4j-over-slf4j:jar:1.7.13:compile
[INFO] |           \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.10; omitted for duplicate)
[INFO] +- com.company.io.spring.boot.starter:central-config-spring-boot-starter:jar:1.0.0:compile
[INFO] |  +- com.company.io.config:config-client:jar:1.0.0:compile
[INFO] |  |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |  +- io.springfox:springfox-swagger-ui:jar:2.2.2:compile
[INFO] |  |  \- io.springfox:springfox-spring-web:jar:2.2.2:compile
[INFO] |  |     \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |  \- io.springfox:springfox-swagger2:jar:2.2.2:compile
[INFO] |     +- io.swagger:swagger-models:jar:1.5.3:compile
[INFO] |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.6.3; omitted for duplicate)
[INFO] |     +- io.springfox:springfox-spi:jar:2.2.2:compile
[INFO] |     |  \- io.springfox:springfox-core:jar:2.2.2:compile
[INFO] |     |     \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |     +- io.springfox:springfox-swagger-common:jar:2.2.2:compile
[INFO] |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |     +- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |     +- org.springframework.plugin:spring-plugin-core:jar:1.2.0.RELEASE:compile
[INFO] |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.10; omitted for duplicate)
[INFO] |     +- org.springframework.plugin:spring-plugin-metadata:jar:1.2.0.RELEASE:compile
[INFO] |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.10; omitted for duplicate)
[INFO] |     \- org.springframework.hateoas:spring-hateoas:jar:0.19.0.RELEASE:compile
[INFO] |        \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] +- com.company.io.spring.boot.starter:ana-spring-boot-starter:jar:1.0.0:compile
[INFO] |  \- com.company.io.auth:ana-client:jar:1.2.0:compile
[INFO] |     +- com.company.io.commons:commons-jersey:jar:1.0.0:compile
[INFO] |     |  \- com.company.io.commons:rules-schema:jar:1.0.0:compile
[INFO] |     |     +- com.company.io.commons:event-schema:jar:1.0.0:compile
[INFO] |     |     |  +- com.company.io.commons:data-schema:jar:1.0.0:compile
[INFO] |     |     |  |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.6; omitted for duplicate)
[INFO] |     |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.6; omitted for duplicate)
[INFO] |     |     +- com.company.io.commons:notification-schema:jar:1.0.0:compile
[INFO] |     |     |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.6; omitted for duplicate)
[INFO] |     |     \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.6; omitted for duplicate)
[INFO] |     +- com.company.io.commons:commons-statsd:jar:1.0.0:compile
[INFO] |     |  +- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |     |  \- org.slf4j:slf4j-simple:jar:1.7.13:compile (version managed from 1.7.12)
[INFO] |     |     \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.12; omitted for duplicate)
[INFO] |     \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO] \- io.company.on.spring.boot.starter:metrics-spring-boot-starter:jar:1.0.0:compile
[INFO]    +- io.dropwizard.metrics:metrics-core:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    +- io.dropwizard.metrics:metrics-annotation:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    +- io.dropwizard.metrics:metrics-healthchecks:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    +- io.dropwizard.metrics:metrics-json:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    +- io.dropwizard.metrics:metrics-jvm:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    +- io.dropwizard.metrics:metrics-servlet:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    +- io.dropwizard.metrics:metrics-servlets:jar:3.1.2:compile
[INFO]    |  \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.7; omitted for duplicate)
[INFO]    \- com.ryantenney.metrics:metrics-spring:jar:3.0.4:compile
[INFO]       \- (org.slf4j:slf4j-api:jar:1.7.13:compile - version managed from 1.7.5; omitted for duplicate)
</code></pre>