Re: [Jazzlib-developers] java.util.ZipFile fix

[John L. <je...@pi...>]

> Hello,
> 
> you have done a good job, I use jazzlib as a replacement for java.util.zip 
> (which does not work) for a Swing-based Zip tool.
> 
> First let me allow the hint that Sun does not permit the usage of "java.util" 
> packages for third parties. Maybe you get into trouble.

These classes are now part of the Classpath project (http://www.gnu.org/software/classpath/).

The Classpath project is a replacement for Sun's class libraries, so java.util.zip is the correct place for these classes.
 
> Now my contribution. There is a bug in your java.util.ZipFile. 
> 
> According to 
> 
>     www.pkware.com/support/appnote.html
> 
> there can be variable-length comments at the end of the file. Your code 
> assumes the central directory size is fixed, but it's not. Some "odd" Zips 
> will fail with a ZipException "Missing end of central directory".
> 
> Attached you find a util.ZipFile source file for your convenience.  It fixes 
> this bug by seeking backward from end of file minus minimum size of the 
> central directory. All Zips I have are recognized now.
> 
> My fix throws a "invalid zip or broken" if it fails to find the header 
> signature.

Your contribution would be more useful if you downloaded the latest version of ZipFile (from 

http://savannah.gnu.org/cgi-bin/viewcvs/classpath/classpath/java/util/zip/ZipFile.java?rev=1.3&content-type=text/vnd.viewcvs-markup

)

And gave us a diff which showed the changes.

Do you have an example of a zip file that has a comment at the end?

Thanks
John Leuner