RFR 6303183: Support NTFS and Unix-style timestamps for entries in Zip files

Xueming Shen xueming.shen at oracle.com
Fri May 24 19:22:04 UTC 2013

I'm trying to address the following two issues

6303183: Support NTFS and Unix-style timestamps for entries in Zip files
7012868: (zipfs) file times of entry in zipfs should always be the same regardless of TimeZone.

which mainly is about the "mtime" field in both loc and cen tables are dos format,
(it means the default time stamp of a zip entry is 2-second granularity time stamp
and timezone sensitive (the time is interpreted  as the "local time" of the timezone
the system is running on, it does not count the time zone difference)

The proposed change here is to

(1) add a Info-ZIP timestamp in entry's extra data (like zip/unzip does), which uses
typical "unix style" second granularity time stamp and is in UTC/GMT timezone

(2) change the ZipEntry.time (renamed to mtime) to be the new unix-style-second
granularity/UTC time, instead of the current "dos style-2-second granularity and
local-time" time stamp, so the set/getTime() can just do the set/get directly without
conversion, however the ZipIn/OutputStream and ZipFile need to handle the conversion
when dealing with the ZIP formatted time stamp.

(3) the "ZipEntry" from ZipOutputStream/ZipFile now has a better time stamp if
the zip file has the Info-ZIP formatted time stamp or the NTFS style time stamp
(which has the microsecond granularity)

(4) For ZipFileSytem, it now output the NTFS style time stamp on Windows platfrom
and Info-ZIP style on non-Windows platform.


I'm yet to run the full regression tests on it,  comment/opinions are appreciated.


There is a more "complete" alternative, in which the creation time and last
access time are supported via ZipEntry with the NTFS/Info-ZIP time stamp,
but I guess there might be no string request for it for now, so it might be
better to stay with the "simple" version for now.


This proposal is to add two new fields, atime and ctime into ZipEntry and generate
NTFS and Info-ZIP's extended timestamp based on the platform os the jvm is running

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