title: Tomcat Build Error: java.lang.NoClassDefFoundError
body: <p>The projet work fine in tomcat localhost but when I upload it in a remote tomcat I get this bug :/ , I have the jar that contain the ImageReaderFactory class in classpath, I didn't understand what can be the problem, 
  I cleared the /tomcat/work/Catalina/localhost folder but always the same bug : <strong>java.lang.NoClassDefFoundError</strong></p>
  
  <pre><code>07-Oct-2019 23:06:25.584 SEVERE [http-apr-8080-exec-267] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [UploadServlet] in context with path [/MyServer] threw exception [Servlet execution threw an exception] with root cause
   java.lang.NoClassDefFoundError: org/dcm4che3/imageio/codec/ImageReaderFactory
      at org.dcm4che3.imageio.plugins.dcm.DicomImageReader.setMetadata(DicomImageReader.java:794)
      at org.dcm4che3.imageio.plugins.dcm.DicomImageReader.readMetadata(DicomImageReader.java:713)
      at org.dcm4che3.imageio.plugins.dcm.DicomImageReader.read(DicomImageReader.java:452)
      at com.project.dicomserver.UploadServlet.getFrameIcon(UploadServlet.java:86)
      ....
  </code></pre>
  
  <p>Does anyone have any ideas? </p>
  
  <p><a href="https://i.stack.imgur.com/n5sEH.png" rel="nofollow noreferrer">image</a></p>