Error 500: java.lang.NoClassDefFoundError: org.apache.commons.io.output.DeferredFileOutputStream

You may face this error when you are working with Apache commons file upload.

Error 500: java.lang.NoClassDefFoundError: org.apache.commons.io.output.DeferredFileOutputStream

In order to solve this error, you need to include the Apache commons IO jar in the lib folder of your web application. You can download this jar from: http://commons.apache.org/io/download_io.cgi.