org.apache.wink.server.internal.RequestProcessor logException ObjectCreationException (500 - Internal Server Error) occurred during the handlers chain invocation
As the name suggests this error is created while apache wink tries to create an object and it fails. The error is not clear but if you log the debug statements present in wink libraries, the thing will become crystal clear to you. Here what happens when you start logging wink activities. This clearly shows that you are missing class "org.apache.poi.ss.usermodel.Workbook". This is contained in Apache poi library and you are missing this jar file. Apache wink depends on few more libraries, so if you see this error, enable logging on wink and find out the missing jar, org.apache.wink.server.internal.RequestProcessor logException ObjectCreationException (500 - Internal Server Error) occurred during the handlers chain invocation org.apache.wink.common.internal.lifecycle.ObjectCreationException: java.lang.NoClassDefFoundError: org.apache.poi.ss.usermodel.Workbook at org.apache.wink.common.internal.lifecycle.CreationUtils.createObject(Creati