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https://issues.apache.org/jira/browse/COMPRESS-36?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13068775#comment-13068775
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Stefan Bodewig commented on COMPRESS-36:
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Just browsed through APPNOTE.TXT
http://www.pkware.com/documents/casestudies/APPNOTE.TXT and took some notes on
what ZIP64 means
* new "end of central directory record" and "end of central directory locator"
records
* sizes in data descriptor will be 8 bytes when written with ZIP64
* there are two different versions of "end of central directory record" for ZIP
spec 4.5-6.1 and spec 6.2+
* will need to set "version needed to extract" to 4.5 or 6.2 depending on the
"eocdr" version used.
* size is stored in an extra field if the archive uses ZIP64 and the size in
the local file header / central directory entry is 0xFFFFFFFF
This is also true for disk number or file numbers (only with 0xFFFF rather
than four bytes)
This new extra field has varying structure, for example it may only contain
the uncompressed size but not the compressed size if the compressed size fits
into four bytes.
* new zip64 extensible data sector
We likely won't implement this (completely) because of
{quote}Portions of this extended tape processing technology is
covered under a pending patent application. The use or
implementation in a product of certain technological
aspects set forth in the current APPNOTE, including
those with regard to strong encryption, patching or
extended tape operations, requires a license from
PKWARE. Please contact PKWARE with regard to acquiring
a license.{quote}
* note that the new sizes potentially exceed Long.MAX_VALUE as they are
unsigned which will cause trouble with ZipFile and its
usage of RandomAccessFile
Same is true for things like ZipArchiveEntry#getSize/setSize
> Add Zip64 Suport
> ----------------
>
> Key: COMPRESS-36
> URL: https://issues.apache.org/jira/browse/COMPRESS-36
> Project: Commons Compress
> Issue Type: New Feature
> Components: Archivers
> Reporter: Christian Grobmeier
> Attachments: zip64-sample.zip
>
>
> Add Zip64 support. This will make it work to deal with zipfiles > 2 GB.
> Planned for compress 1.1
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