Hi Got this stacktrace with the coment "Please raise a bug". (The cause was my fault) My processSheet(...) is asynchronous and the workbook had been closed from outside in the meantime. So you have to decide, if this is a bug or a PEBCAK problem. org.apache.poi.openxml4j.exceptions.OpenXML4JRuntimeException: Rule M2.4 exception : this error should NEVER happen! Please raise a bug at https://bz.apache.org/bugzilla/enter_bug.cgi?product=POI and attach a file that triggers it, thanks! at org.apache.poi.openxml4j.opc.internal.ContentTypeManager.getContentType(ContentTypeManager.java:343) at org.apache.poi.openxml4j.opc.internal.ContentTypeManager.removeContentType(ContentTypeManager.java:256) at org.apache.poi.openxml4j.opc.OPCPackage.removePart(OPCPackage.java:943) at org.apache.poi.openxml4j.opc.PackagePart.getOutputStream(PackagePart.java:522) at org.apache.poi.xssf.usermodel.XSSFWorkbook.commit(XSSFWorkbook.java:1678) at org.apache.poi.POIXMLDocumentPart.onSave(POIXMLDocumentPart.java:341) at org.apache.poi.POIXMLDocument.write(POIXMLDocument.java:206) at com.dpd.geoRouting.testService.service.ExcelFileService.processSheet(ExcelFileService.java:241) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081) at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153) at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4786) at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656) at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822) at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608) at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:55) at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883) at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822) at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369) at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4758) at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746) at com.sun.ejb.containers.EjbAsyncTask.call(EjbAsyncTask.java:101)
I have updated the error message if you try to write a document that was already closed via r1744306, in a single-threaded app this cased an NullPointerException. I don't think we can do much more as POI does not guarantee thread-safety when one workbook is used in multiple threads concurrently.