title: Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1 - kafka storm integration
body: <p>I am working on kafka strom integration. Im stuck with an error. The Build Fails when I try to Run it using<br>
  <code>mvn -e -f m2-pom.xml compile exec:java -Dexec.classpathScope=compile -Dexec.mainClass=storm.starter.MainTopology</code></p>
  
  <pre><code>[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:java  
  (default-cli) on project storm-starter: The parameters 'mainClass' for goal 
   org.codehaus.mojo:exec-maven-plugin:1.2.1:java are missing or invalid
  </code></pre>
  
  <p>This is a snippet of the pom.xml file:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;plugin&gt;
      &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
      &lt;artifactId&gt;exec-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.2.1&lt;/version&gt;
      &lt;executions&gt;
        &lt;execution&gt;
          &lt;goals&gt;
            &lt;goal&gt;exec&lt;/goal&gt;
          &lt;/goals&gt;
        &lt;/execution&gt;
      &lt;/executions&gt;
      &lt;configuration&gt;
        &lt;executable&gt;java&lt;/executable&gt;
        &lt;includeProjectDependencies&gt;true&lt;/includeProjectDependencies&gt;
        &lt;includePluginDependencies&gt;true&lt;/includePluginDependencies&gt;
        &lt;classpathScope&gt;compile&lt;/classpathScope&gt;
        &lt;mainClass&gt;${storm.topology}&lt;/mainClass&gt;
      &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>I tried </p>
  
  <pre><code>rm -rf ~/.m2/
  mvn clean install
  </code></pre>
  
  <p>I am using storm-0.9.0-rc3 and kafka-0.7.2</p>