Steps to Reproduce

Import attached file into a Keikai page

Current Result

io.keikai.importer.ImportException: Fail to import stylesheet from book repro.xlsx
	at io.keikai.importer.XlsxImporter.imports(XlsxImporter.java:273)
	at io.keikai.range.impl.imexp.ExcelImportAdapter.imports(ExcelImportAdapter.java:48)
	at io.keikai.api.impl.ImporterImpl.imports(ImporterImpl.java:58)
	at io.keikai.api.impl.ImporterImpl.imports(ImporterImpl.java:90)
	at io.keikai.api.impl.ImporterImpl.imports(ImporterImpl.java:77)
	at io.keikai.app.repository.impl.SimpleRepository.load(SimpleRepository.java:62)
	at io.keikaiex.app.impl.BookManagerEx.readBook(BookManagerEx.java:62)
	at io.keikai.app.ui.dlg.OpenManageBookCtrl.loadBook(OpenManageBookCtrl.java:202)
	at io.keikai.app.ui.dlg.OpenManageBookCtrl.onOpen(OpenManageBookCtrl.java:100)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.zkoss.zk.ui.select.Selectors$ComposerEventListener.onEvent(Selectors.java:687)
	at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:3184)
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3154)
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3096)
	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138)
	at org.zkoss.zk.ui.event.Events.sendEvent(Events.java:353)
	at org.zkoss.zk.ui.event.Events.sendEvent(Events.java:377)
	at org.zkoss.zk.ui.AbstractComponent$ForwardListener.onEvent(AbstractComponent.java:3629)
	at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:3184)
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3154)
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3096)
	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138)
	at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1890)
	at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1662)
	at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1329)
	at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:611)
	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:487)
	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:495)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:401)
	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
	at org.mortbay.jetty.Server.handle(Server.java:326)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
	at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:945)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.NullPointerException
	at io.keikai.importer.XlsxExtractor$XlsxPatternExtractor.getFgColor(XlsxExtractor.java:770)
	at io.keikai.importer.XlsxImporter.importFills(XlsxImporter.java:603)
	at io.keikai.importer.XlsxImporter.importStyleSheet(XlsxImporter.java:533)
	at io.keikai.importer.XlsxImporter.imports(XlsxImporter.java:194)
	... 47 more

Expected Result

 Import file, no exception

Debug Information

This likely caused by a non-standard export (file origin currently not identified, attached sample manually modified to trigger the issue)

Even though this is not a keikai issue, keikai should be hardened if possible to not trust that the imported xml will automatically be well-formed, and skip empty elements if any. 

Caused by unexpected empty <fill> element in style.xml

<fills count="7"><fill><patternFill /></fill>...

expected:

<fills count="7"><fill><patternFill patternType="none"/></fill>...

Workaround

 Open in Excel, save file (Excel will automatically save in a valid format)

Similar case

A different failed case for the same root cause.

io.keikai.importer.ImportException: Fail to import sheet view in sheet Ratios from book financial_highlights_source_2205.xlsx
at io.keikai.importer.XlsxImporter.imports(XlsxImporter.java:273)
at io.keikai.range.impl.imexp.ExcelImportAdapter.imports(ExcelImportAdapter.java:48)
at io.keikai.range.impl.imexp.AbstractImporter.imports(AbstractImporter.java:57)
at io.keikai.ui.Spreadsheet.getSBook(Spreadsheet.java:720)
at io.keikai.ui.Spreadsheet.getSelectedSSheet(Spreadsheet.java:900)
at io.keikai.ui.Spreadsheet.doInvalidate(Spreadsheet.java:2709)
at io.keikai.ui.Spreadsheet.invalidate(Spreadsheet.java:2566)
at io.keikai.ui.Spreadsheet.setSrc(Spreadsheet.java:949)
at sun.reflect.GeneratedMethodAccessor2171.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.zkoss.lang.reflect.Fields.set(Fields.java:153)
at org.zkoss.lang.reflect.Fields.setByCompound(Fields.java:79)
at io.keikai.jsp.ui.SpreadsheetTag.evaluateDynaAttribute(SpreadsheetTag.java:173)
at io.keikai.jsp.ui.SpreadsheetTag.evaluateDynaAttributes(SpreadsheetTag.java:158)
at io.keikai.jsp.ui.SpreadsheetTag.initComponent(SpreadsheetTag.java:120)
at io.keikai.jsp.ui.SpreadsheetTag$1.service(SpreadsheetTag.java:77)
at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:522)
at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:373)
at org.zkoss.zkplus.embed.Renders.render(Renders.java:130)
at org.zkoss.zkplus.embed.Renders.render(Renders.java:88)
at io.keikai.jsp.ui.SpreadsheetTag.doTag(SpreadsheetTag.java:74)
at jsp_servlet.los._customer._financials.excel_display._jspService(_excel_display.java:138)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:35)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:295)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:260)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:137)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:353)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at com.integrosys.sml.ui.common.xss.XSSFilter.doFilter(XSSFilter.java:83)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:32)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3797)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3763)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:344)
at weblogic.security.service.SecurityManager.runAsForUserCode(SecurityManager.java:197)
at weblogic.servlet.provider.WlsSecurityProvider.runAsForUserCode(WlsSecurityProvider.java:203)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:71)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2451)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2299)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2277)
at weblogic.servlet.internal.ServletRequestImpl.runInternal(ServletRequestImpl.java:1720)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1680)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:272)
at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:352)
at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:337)
at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:57)
at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)
at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:655)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:420)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:360)
Caused By: java.lang.NullPointerException
at io.keikai.importer.XlsxExtractor$XlsxSheetPropertiesExtractor.getTabColor(XlsxExtractor.java:2363)
at io.keikai.importer.XlsxImporter.importSheet(XlsxImporter.java:3021)
at io.keikai.importer.XlsxImporter.lambda$importSheets$8(XlsxImporter.java:2957)
at java.util.ArrayList.forEach(ArrayList.java:1259)
at io.keikai.importer.XlsxImporter.importSheets(XlsxImporter.java:2956)
at io.keikai.importer.XlsxImporter.imports(XlsxImporter.java:212)
at io.keikai.range.impl.imexp.ExcelImportAdapter.imports(ExcelImportAdapter.java:48)
at io.keikai.range.impl.imexp.AbstractImporter.imports(AbstractImporter.java:57)
at io.keikai.ui.Spreadsheet.getSBook(Spreadsheet.java:720)