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Posted to user@poi.apache.org by Burkhard Losch <Bu...@kisters.de> on 2017/01/12 09:12:37 UTC
Close a Workbook, what exactly is the meaning of this function?
Dear All,
we use XSSFWorkbook, create it with a file name (not with an InputStream),
and make modifications on the workbook.
If we close the workbook, sometimes the changes are written, sometimes
not.
It looks like, if we call the write function with any outputstream, the
later call to close will overwrite the initial file. But if I don't call
write, the initial file remains unchanged.
I think, there are two issues:
- the documentation says, close only would close the open stream, but in
fact the source code looks like that changes should be saved back to the
file.
- the changes are only written by calling close, if a call to write
happened before. So, if I want to save the original XLSX file, I need to
save it twice.
The workaround is, not to use the constructor which takes a File or a
String, but to use the constructor with InputStream, close the stream,
make the changes on the workbook and then write it back to the
inputstream's location with the write function.
The workbook.close() function is then not required to be called anymore.
Does someone have experience with the correct usage of the API according
to this? May be I miss some function call, which controls to write the
file back on close.
The actual use case is :
use a XLSX workbook as a template
open the file, write some content, write it back to a new file without
changing the original template.
I use now the workaround to first copy the template to my destination
file, open that one with the InputStream constructor, close the stream at
the end, and write the workbook back with write() to the copied template
file.
Background:
For our ETL-scripting language KiScript we provide an API for POI, which
is successfully in use.
This is, how the KiScript code looks like using the workaround, it's
similar to the JAVA api,
module de.kisters.kiscript.poi.ssf.SSF
File f = new File("c:\temp\myTemplate.xlsx")
File target = new File("myDestination.xlsx")
f.copy(target.getAbsolutePath())
SSFWorkbook wb = SSFWorkbook.createXSSFWorkbook(target.InputStream())
SSFSheet sh = wb.getSheetAt(0)
// write a table to the workbook's sheet.
sh.writeSheetVertically(Session.getList(), 2, 0, false)
target.close()
wb.write()
wb.writeToFile(target)
wb.close()
Regards
Burkhard
--------------------------------------------------------------------------------------------------------------------------------------------
Burkhard Losch - KISTERS AG - Pascalstraße 8+10 - 52076 Aachen - Germany
Handelsregister Aachen, HRB-Nr. 7838 | Vorstand: Klaus Kisters, Hanns Kisters | Aufsichtsratsvorsitzender: Dr. Thomas Klevers
Phone: +49 2408 9385 -112 | Mobile: +49 176 19671041 | Fax: +49 2408 9385 -555 | E-Mail: burkhard.losch@kisters.de | WWW: http://www.kisters.de
--------------------------------------------------------------------------------------------------------------------------------------------
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Re: Close a Workbook, what exactly is the meaning of this function?
Posted by Javen O'Neal <on...@apache.org>.
Related: https://bz.apache.org/bugzilla/show_bug.cgi?id=57919
On Jan 12, 2017 02:23, "Dominik Stadler" <do...@gmx.at> wrote:
> Hi,
>
> that sound like a bug, there were some discussions before about
> save-behavior and ways to save changes back to the same file, however I
> think we should not write back to the original file in some obscure
> automated way like you describe, can you create a bug-report with the
> sample code so one of us takes a closer look?
>
> For now the workaround sounds valid.
>
> Dominik.
>
> On Thu, Jan 12, 2017 at 10:12 AM, Burkhard Losch <
> Burkhard.Losch@kisters.de>
> wrote:
>
> > Dear All,
> > we use XSSFWorkbook, create it with a file name (not with an
> InputStream),
> > and make modifications on the workbook.
> >
> > If we close the workbook, sometimes the changes are written, sometimes
> > not.
> >
> > It looks like, if we call the write function with any outputstream, the
> > later call to close will overwrite the initial file. But if I don't call
> > write, the initial file remains unchanged.
> > I think, there are two issues:
> > - the documentation says, close only would close the open stream, but in
> > fact the source code looks like that changes should be saved back to the
> > file.
> > - the changes are only written by calling close, if a call to write
> > happened before. So, if I want to save the original XLSX file, I need to
> > save it twice.
> >
> > The workaround is, not to use the constructor which takes a File or a
> > String, but to use the constructor with InputStream, close the stream,
> > make the changes on the workbook and then write it back to the
> > inputstream's location with the write function.
> > The workbook.close() function is then not required to be called anymore.
> >
> > Does someone have experience with the correct usage of the API according
> > to this? May be I miss some function call, which controls to write the
> > file back on close.
> >
> > The actual use case is :
> > use a XLSX workbook as a template
> > open the file, write some content, write it back to a new file without
> > changing the original template.
> >
> > I use now the workaround to first copy the template to my destination
> > file, open that one with the InputStream constructor, close the stream at
> > the end, and write the workbook back with write() to the copied template
> > file.
> >
> >
> > Background:
> > For our ETL-scripting language KiScript we provide an API for POI, which
> > is successfully in use.
> >
> > This is, how the KiScript code looks like using the workaround, it's
> > similar to the JAVA api,
> >
> > module de.kisters.kiscript.poi.ssf.SSF
> > File f = new File("c:\temp\myTemplate.xlsx")
> > File target = new File("myDestination.xlsx")
> > f.copy(target.getAbsolutePath())
> > SSFWorkbook wb = SSFWorkbook.createXSSFWorkbook(target.InputStream())
> > SSFSheet sh = wb.getSheetAt(0)
> > // write a table to the workbook's sheet.
> > sh.writeSheetVertically(Session.getList(), 2, 0, false)
> > target.close()
> > wb.write()
> > wb.writeToFile(target)
> > wb.close()
> >
> >
> >
> >
> >
> >
> > Regards
> > Burkhard
> > ------------------------------------------------------------
> > ------------------------------------------------------------
> > --------------------
> > Burkhard Losch - KISTERS AG - Pascalstraße 8+10 - 52076 Aachen - Germany
> > Handelsregister Aachen, HRB-Nr. 7838 | Vorstand: Klaus Kisters, Hanns
> > Kisters | Aufsichtsratsvorsitzender: Dr. Thomas Klevers
> > Phone: +49 2408 9385 -112 | Mobile: +49 176 19671041 | Fax: +49 2408 9385
> > -555 | E-Mail: burkhard.losch@kisters.de | WWW: http://www.kisters.de
> > ------------------------------------------------------------
> > ------------------------------------------------------------
> > --------------------
> > Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte
> > Informationen. Wenn Sie nicht der richtige Adressat sind oder diese
> E-Mail
> > irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und
> > vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte
> > Weitergabe dieser Mail ist nicht gestattet.
> > This e-mail may contain confidential and/or privileged information. If
> you
> > are not the intended recipient (or have received this e-mail in error)
> > please notify the sender immediately and destroy this e-mail. Any
> > unauthorised copying, disclosure or distribution of the material in this
> > e-mail is strictly forbidden.
>
Re: Close a Workbook, what exactly is the meaning of this function?
Posted by Dominik Stadler <do...@gmx.at>.
Hi,
that sound like a bug, there were some discussions before about
save-behavior and ways to save changes back to the same file, however I
think we should not write back to the original file in some obscure
automated way like you describe, can you create a bug-report with the
sample code so one of us takes a closer look?
For now the workaround sounds valid.
Dominik.
On Thu, Jan 12, 2017 at 10:12 AM, Burkhard Losch <Bu...@kisters.de>
wrote:
> Dear All,
> we use XSSFWorkbook, create it with a file name (not with an InputStream),
> and make modifications on the workbook.
>
> If we close the workbook, sometimes the changes are written, sometimes
> not.
>
> It looks like, if we call the write function with any outputstream, the
> later call to close will overwrite the initial file. But if I don't call
> write, the initial file remains unchanged.
> I think, there are two issues:
> - the documentation says, close only would close the open stream, but in
> fact the source code looks like that changes should be saved back to the
> file.
> - the changes are only written by calling close, if a call to write
> happened before. So, if I want to save the original XLSX file, I need to
> save it twice.
>
> The workaround is, not to use the constructor which takes a File or a
> String, but to use the constructor with InputStream, close the stream,
> make the changes on the workbook and then write it back to the
> inputstream's location with the write function.
> The workbook.close() function is then not required to be called anymore.
>
> Does someone have experience with the correct usage of the API according
> to this? May be I miss some function call, which controls to write the
> file back on close.
>
> The actual use case is :
> use a XLSX workbook as a template
> open the file, write some content, write it back to a new file without
> changing the original template.
>
> I use now the workaround to first copy the template to my destination
> file, open that one with the InputStream constructor, close the stream at
> the end, and write the workbook back with write() to the copied template
> file.
>
>
> Background:
> For our ETL-scripting language KiScript we provide an API for POI, which
> is successfully in use.
>
> This is, how the KiScript code looks like using the workaround, it's
> similar to the JAVA api,
>
> module de.kisters.kiscript.poi.ssf.SSF
> File f = new File("c:\temp\myTemplate.xlsx")
> File target = new File("myDestination.xlsx")
> f.copy(target.getAbsolutePath())
> SSFWorkbook wb = SSFWorkbook.createXSSFWorkbook(target.InputStream())
> SSFSheet sh = wb.getSheetAt(0)
> // write a table to the workbook's sheet.
> sh.writeSheetVertically(Session.getList(), 2, 0, false)
> target.close()
> wb.write()
> wb.writeToFile(target)
> wb.close()
>
>
>
>
>
>
> Regards
> Burkhard
> ------------------------------------------------------------
> ------------------------------------------------------------
> --------------------
> Burkhard Losch - KISTERS AG - Pascalstraße 8+10 - 52076 Aachen - Germany
> Handelsregister Aachen, HRB-Nr. 7838 | Vorstand: Klaus Kisters, Hanns
> Kisters | Aufsichtsratsvorsitzender: Dr. Thomas Klevers
> Phone: +49 2408 9385 -112 | Mobile: +49 176 19671041 | Fax: +49 2408 9385
> -555 | E-Mail: burkhard.losch@kisters.de | WWW: http://www.kisters.de
> ------------------------------------------------------------
> ------------------------------------------------------------
> --------------------
> Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte
> Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail
> irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und
> vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte
> Weitergabe dieser Mail ist nicht gestattet.
> This e-mail may contain confidential and/or privileged information. If you
> are not the intended recipient (or have received this e-mail in error)
> please notify the sender immediately and destroy this e-mail. Any
> unauthorised copying, disclosure or distribution of the material in this
> e-mail is strictly forbidden.