Using NIO2 for writing zip file entries without corresponding folder entries

Alan Bateman Alan.Bateman at
Wed Oct 10 11:50:37 UTC 2018

On 10/10/2018 12:31, Rafael Winterhalter wrote:
> Hi,
> I was wondering why the ZipFileSystem checked for the existence of a 
> file's parents before writing a file. Writing folder entries is not a 
> requirement in the specification for zip files and I find it strange 
> that the implementation enforces it. I found that even to be 
> problematic when altering a zip file where NIO2 requires you to add 
> folder entries that did not exist before.
If you using a zip file system to create a new zip file then it 
shouldn't be a surprise that you need to create a directory before 
creating entries in the directory. The zip file system is just trying to 
behave like a regular file system. The zip file system provider does 
lack a configuration option to strip directories when writing, that 
could potentially be added if important.

One other thing is that the zip file system provider can open existing 
zip files that don't have entries for directories, it's should emulate 
them for that scenario.


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