Re: [cross-project-issues-dev] JarProcessor and Java versions

[Thomas Hallgren <thomas@xxxxxxx>]

OK, now I know what's going on. When a Java 1.6 pack200 encounters a jar 
file that contains no classfiles, it doesn't bother maintaining backward 
compatibility. So when it packs for instance 
org.eclipse.swt_3.3.2.v3347.jar, it creates a magic that can be unpacked 
by Java 1.6 only.

This is perhaps not a bug, but it would be cool if the jarProcessor 
could cater for this and actually refrain from packing files that 
contains no classes.

Thanks for your patience :-)

Regards,
Thomas Hallgren


Thomas Hallgren wrote:
> Andrew, John,
> Thanks for your input. I am using Java 1.6 to do the packaging. The 
> problem arises when someone using Java 1.5 tries to unpack.
>
> The whole objective with my exercise is to be able to build Java 1.5 
> compatible binaries with only Java 1.6 installed so pointing to a Java 
> 1.5 version of the pack200 is not an option for me.
>
> I looked at the API docs for pack200. It says that "In order to 
> maintain backward compatibility, if the input JAR-files are solely 
> comprised of 1.5 (or lesser) classfiles, a 1.5 compatible pack file is 
> produced. Otherwise a 1.6 compatible pack200 file is produced." So I 
> checked the original zip file and its contained jar files, nested jar 
> files and all files contained in them. I have no class file that has a 
> major version higher then 49 (Java 6 is >= 50). The same is true after 
> the file has been normalized. So something else must be happening.
>
> - thomas
>
>
> Andrew Niefer wrote:
> > If this error message is implying that your classes were compiled 
> > 1.6, it would be a good idea to use a 1.6 vm to do the packing.
> > As John points out there is an option to choose the pack200 by 
> > setting  system property to the directory containing the pack200 tools.
> >
> > -Andrew
> >
> >
> >
> > *John Arthorne/Ottawa/IBM@IBMCA*
> > Sent by: cross-project-issues-dev-bounces@xxxxxxxxxxx
> >
> > 11/30/2007 09:28 AM
> > Please respond to
> > Cross project issues <cross-project-issues-dev@xxxxxxxxxxx>
> >
> >
> >     
> > To
> >     Cross project issues <cross-project-issues-dev@xxxxxxxxxxx>
> > cc
> >     
> > Subject
> >     Re: [cross-project-issues-dev] JarProcessor and Java versions
> >
> >
> >
> >     
> >
> >
> >
> >
> >
> >
> > This page lists all the options supported by the jar processor:
> >
> > http://wiki.eclipse.org/JarProcessor_Options
> >
> > Note at the bottom of the page there is a system property where you 
> > can specify the exact pack200 command to use.
> > --
> >
> >
> > *Thomas Hallgren <thomas@xxxxxxx>*
> > Sent by: cross-project-issues-dev-bounces@xxxxxxxxxxx
> >
> > 11/29/2007 07:32 PM
> > Please respond to
> > Cross project issues <cross-project-issues-dev@xxxxxxxxxxx>
> >
> >     
> > To
> >     Cross project issues <cross-project-issues-dev@xxxxxxxxxxx>
> > cc
> >     
> > Subject
> >     [cross-project-issues-dev] JarProcessor and Java versions
> >
> >
> >
> >
> >     
> >
> >
> >
> >
> >
> >
> > Hi,
> > I'm wondering if there are some options that can be passed to the
> > Eclipse jarProcessor that will restrict the pack200 to a certain target
> > level. My objective is to restrict builds to a certain target level
> > (Java 1.5) regardless of what JVM that is used for the build. The build
> > uses the ant task 'eclipse.jarProcessor'
> >
> > At present, a machine running Java 1.5 will fail with the following on
> > the top of the stack:
> >
> > Stack Trace:
> > java.io.IOException: Corrupted pack file: magic/ver = CAFED00D/160.1
> > should be CAFED00D/150.7
> >
> > at com.sun.java.util.jar.pack.NativeUnpack.start(Native Method)
> > at com.sun.java.util.jar.pack.NativeUnpack.run(Unknown Source)
> > at com.sun.java.util.jar.pack.NativeUnpack.run(Unknown Source)
> > at com.sun.java.util.jar.pack.UnpackerImpl.unpack(Unknown Source)
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