title: JSF Configuration of the file upload filter
body: <p>I am trying to use fileUpload component. As I read from primefaces user guide, I have to configure the fileUpload filter.</p>
  
  <pre><code>&lt;filter&gt;
      &lt;filter-name&gt;PrimeFaces FileUpload Filter&lt;/filter-name&gt;
      &lt;filter-class&gt;
          org.primefaces.webapp.filter.FileUploadFilter
      &lt;/filter-class&gt;
  &lt;/filter&gt;
  &lt;filter-mapping&gt;
      &lt;filter-name&gt;PrimeFaces FileUpload Filter&lt;/filter-name&gt;
      &lt;servlet-name&gt;Faces Servlet&lt;/servlet-name&gt;
  &lt;/filter-mapping&gt;
  </code></pre>
  
  <p>I added these lines (suggested by the guide) to the web.xml file.</p>
  
  <p>Now, when the server (Tomcat 7) is starting, I get an exception and the server fails to start. I'll post part of stack trace.</p>
  
  <pre><code>GRAVE: A child container failed during start
  java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/webApp]]
  at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)
  at...
  Caused by: java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory
  at....
  Caused by: java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
  </code></pre>
  
  <p>Is the configuration of this filter useful? How can I configure it properly?</p>