title: org.apache.commons cannot be resolved to a type
body: <p>I have tried an payment gateway integration. The code given by the gate way have some error</p>
  
  <pre><code> byte[] hexBytes = new org.apache.commons.codec.binary.Hex().encode(mac.doFinal(data.getBytes()));
  </code></pre>
  
  <p>The error is</p>
  
  <blockquote>
    <p>org.apache.commons cannot be resolved to a type</p>
  </blockquote>