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https://issues.apache.org/jira/browse/COMPRESS-474?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Krzysztof Rzymkowski updated COMPRESS-474:
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Description:
Excel's xlsx files are generally zip archives. But Excel has a very specific
and strict ZIP64 implementation.
Connected Apache POI issue:
[https://bz.apache.org/bugzilla/show_bug.cgi?id=57342
]My blog post with all the details:
[https://rzymek.github.io/post/excel-zip64/]
My observations on Excel requirements:
# If file size is > 4gb, then zip spec version 4.5 must be set in Local Header
File
# In streaming creation the zero file sizes must be in 32 field, not in LHF's
ZIP64 extra field data.
# ZIP64 extra field in Central Directory must not include
relativeHeaderOffset. Only size or size and compressed size
# ZIP64 Central Directory is not supported
I did verify these in a +prototype+ repository at
[https://github.com/rzymek/commons-compress/pull/1/files]. This is just a
playground where I've tested the changes to verify that Excel opens the
generated file.
Test project: https://github.com/rzymek/xlsx-compress64-test
was:
Excel's xlsx files are generally zip archives. But Excel has a very specific
and strict ZIP64 implementation.
Connected Apache POI issue:
[https://bz.apache.org/bugzilla/show_bug.cgi?id=57342
]My blog post with all the details: [https://rzymek.github.io/post/excel-zip64/]
My observations on Excel requirements:
# If file size is > 4gb, then zip spec version 4.5 must be set in Local Header
File
# In streaming creation the zero file sizes must be in 32 field, not in LHF's
ZIP64 extra field data.
# ZIP64 extra field in Central Directory must not include
relativeHeaderOffset. Only size or size and compressed size
# ZIP64 Central Directory is not supported
I did verify these in a +prototype+ repository at
[https://github.com/rzymek/commons-compress/pull/1/files]. This is just a
playground where I've tested the changes to verify that Excel opens the
generated file.
> xlsx zip64 compatibility
> ------------------------
>
> Key: COMPRESS-474
> URL: https://issues.apache.org/jira/browse/COMPRESS-474
> Project: Commons Compress
> Issue Type: Bug
> Components: Archivers
> Affects Versions: 1.19
> Reporter: Krzysztof Rzymkowski
> Priority: Major
>
> Excel's xlsx files are generally zip archives. But Excel has a very specific
> and strict ZIP64 implementation.
> Connected Apache POI issue:
> [https://bz.apache.org/bugzilla/show_bug.cgi?id=57342
> ]My blog post with all the details:
> [https://rzymek.github.io/post/excel-zip64/]
> My observations on Excel requirements:
> # If file size is > 4gb, then zip spec version 4.5 must be set in Local
> Header File
> # In streaming creation the zero file sizes must be in 32 field, not in
> LHF's ZIP64 extra field data.
> # ZIP64 extra field in Central Directory must not include
> relativeHeaderOffset. Only size or size and compressed size
> # ZIP64 Central Directory is not supported
> I did verify these in a +prototype+ repository at
> [https://github.com/rzymek/commons-compress/pull/1/files]. This is just a
> playground where I've tested the changes to verify that Excel opens the
> generated file.
> Test project: https://github.com/rzymek/xlsx-compress64-test
>
>
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