java.lang.NoClassDefFoundError: org/apache/poi/ss/usermodel/RichTextString at org.primefaces.component.export.ExporterFactory.getExporterForType

Question

I used the same sample code Primefaces has in its web page:

Answer 1

javax.servlet.ServletException: org/apache/poi/ss/usermodel/RichTextString

Look further down in the stacktrace. I bet that the root cause is either a NoClassDefFoundError or ClassNotFoundException? In that case, this just means that you forgot to install Apache POI.

Download this Apache POI zip file, extract it, put poi-3.8-20120326.jar in /WEB-INF/lib folder and rebuild/redeploy/restart the webapp.