Problem Description:

Customer reported that:

We use ZK's Apache POI library to export reports to Excel files(*.XLSX).
We have found a bug in implementation of the Cell.setCellFormula method.
Formula "A1*0.8" (in Polish default system settings) is written as "A1*0,8"

• Dot is replaced by colon. - We have executed "getCellFormula" in the next
  line of code.
  Trying to open such file we have been told that the file is corrupted. - MS
  Excel expects a dot in formula. Manual change in xml file have proved this.

What are we doing wrong ? Are there any options to set to do this right ?
It looks like setCellFormula method acquires decimal system settings for
presentation. In my opinion, it should not.

For now we have a workaround: Constant "0.8" is replaced by "(8/10)".

Steps to Reproduce:

1. run with attached zul and composer.
2. Click the "Set formula with Range" button(or "Set formula" button )
3. click "Export to Excel" button to export
4. open the exported Excel file with Excel 2007

Actual:

Excel show messages said "Excel found unreadable content in 'corruptFormula.xlsx'. Do you want to recover the contents of this workbook?..."

If you open the corrupted file with "Open XML SDK 2.5 Productivity Tool for Microsoft Office" to see value in XML file, you can see:

<x:row r="2" xmlns:x="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
  <x:c r="A2">
    <x:f>A1*0,8</x:f>
  </x:c>
</x:row>

Exception printed in console

嚴重的: error evaluating formula at A3
java.lang.IllegalStateException: evaluation stack not empty
at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateFormula(WorkbookEvaluator.java:595)
at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateAny(WorkbookEvaluator.java:313)
at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluate(WorkbookEvaluator.java:252)
at org.zkoss.poi.xssf.usermodel.XSSFFormulaEvaluator.evaluateFormulaCellValue(XSSFFormulaEvaluator.java:267)
at org.zkoss.poi.xssf.usermodel.XSSFFormulaEvaluator.evaluate(XSSFFormulaEvaluator.java:120)
at org.zkoss.zss.model.impl.BookHelper.evaluate(BookHelper.java:469)
at org.zkoss.zss.model.impl.BookHelper.getFormatText(BookHelper.java:1021)
at org.zkoss.zss.model.impl.RangeImpl.getFormatText(RangeImpl.java:228)
at org.zkoss.zss.ui.impl.Utils.getFormatText(Utils.java:869)
at org.zkoss.zss.ui.fn.UtilFns.getCellFormatText(UtilFns.java:99)
at org.zkoss.zss.ui.Spreadsheet$ExtraCtrl.getCellAttr(Spreadsheet.java:3111)
at org.zkoss.zss.ui.Spreadsheet$ExtraCtrl.getRangeAttrs(Spreadsheet.java:2933)
at org.zkoss.zss.ui.Spreadsheet.responseUpdateCell(Spreadsheet.java:2557)
at org.zkoss.zss.ui.Spreadsheet.updateCell(Spreadsheet.java:2526)
at org.zkoss.zss.ui.Spreadsheet.access$4100(Spreadsheet.java:179)
at org.zkoss.zss.ui.Spreadsheet$InnerDataListener.onContentChange(Spreadsheet.java:2240)
at org.zkoss.zss.ui.Spreadsheet$InnerDataListener.access$1100(Spreadsheet.java:1989)
at org.zkoss.zss.ui.Spreadsheet$InnerDataListener$7.onEvent(Spreadsheet.java:2032)
at org.zkoss.zss.engine.event.EventDispatchListener.onEvent(EventDispatchListener.java:43)
at org.zkoss.zssex.engine.impl.RefBookImpl$DelegateListener.onEvent(Unknown Source)
at org.zkoss.zk.ui.event.impl.DesktopEventQueue$QueueListener.onEvent(DesktopEventQueue.java:145)
at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:2732)
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2703)
at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2644)
at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)
at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1710)
at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1495)
at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1205)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:583)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:481)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:489)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:401)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$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)