Flushing ZipFS

[Daniel Latrémolière]

When using JDK7 ZipFS provider, I have seen that the Zip file is not 
updated even many hours after writing new files in Zip (closing 
OutputStream of new entries, but not closing Zip instance of 
FileSystem). When closing application (and particularly Zip FileSystem), 
the new entries are added to the zip file.

It seems ZipFS provider has a cache of files and that seem logical, but 
I don't see a method for flushing this cache (in a valid Zip file would 
be better). I would have expected to see a method flush() in 
java.nio.file.FileSystem, but it is not the case. Is there a clean 
solution (excepted closing and reopening regularly the FileSystem)?

Thanks.