title: java.lang.NoClassDefFoundError: org/apache/commons/collections/Transformer
body: <p>I am receiving the following error <code>java.lang.NoClassDefFoundError: org/apache/commons/collections/Transformer</code> trying to use <code>BeanMap</code> from the Apache Commons BeanUtils library. </p>
  
  <p>It is generated from the following code: <code>BeanMap studentBeanMap = new BeanMap(cohortStudentData.get(row));</code> where <code>cohortStudentData</code> is a list of beans.</p>
  
  <p>I am using <code>BeanListHandler</code> from Apache DBUtils to form the list of beans from a database.</p>
  
  <p>I understand from <a href="https://issuetracker.springsource.com/browse/EBR-420" rel="noreferrer">this</a> and <a href="https://issues.jboss.org/browse/AS7-1391" rel="noreferrer">this</a> bug report that <code>BeanMap</code> is dependant on the Apache Collections framework. However, I have imported all relevant libraries into my project and into my class, as you can see below:</p>
  
  <p><img src="https://i.stack.imgur.com/wj83h.png" alt="External Library List"></p>
  
  <p><img src="https://i.stack.imgur.com/LYsPY.png" alt="Import Statements"></p>
  
  <p>Does anyone know why this might be happening?</p>