title: How do I add my class/jar when the preview tab is throwing ClassNotFoundException?
body: <p>I have connected an Oracle server with all of my tables to JasperReports through a JDBC connection, and managed to load my tables and fields on the report. I've also added the jdbc8.jar as a classpath to my new Data Adapter, but unfortunately, when I try to preview my new report, I get the following compilation error : </p>
  
  <pre><code>java.lang.ClassNotFoundException: oracle.jdbc.OracleClob cannot be found by net.sf.jasperreports_6.6.0.final --- net.sf.jasperreports.engine.design.JRDesignField@47bae235
  </code></pre>