[Wrapper-user] Detecting JVM version (32 bit vs. 64 bit) (was Re: getting hardware arch using just java)

[David F. <dav...@zi...>]

Thanks Leif, but I think I wasn't clear enough in my first post.

I am trying to build one installer that takes care of all java =20
supported OS / JVM possibilities. I have reviewed the testwrapper =20
shell script in the JWS bin directory. As I understand it, it works =20
as follows:

By default it will use the 32 bit version of the wrapper binary. If =20
it can't find that, it will test for the 64 bit version (or in the =20
case of Mac OS X, the universal binary) and run that instead. If it =20
can't find either, it will display an error message.

Please correct me if I'm wrong, but it would appear that it is my =20
software installer's responsibility to detect if the user is =20
installing on a  64-bit JVM. If both the 32 bit and 64 bit wrapper =20
binaries were present, that it would attempt to use the 32 bit =20
wrapper binary first and it would fail on a 64 bit JVM environment.

Is there any way to detect if they are using a 64-bit JVM? I would =20
like to avoid having to display an error and requiring the user to =20
delete the 32-bit wrapper binary manually before restarting.  Is the =20
best we can do to document the 64-bit JVM situation?

Thanks for any clarity anyone can share about detecting 64-bit JVM or =20=

the inner workings of JWS that I may be mistaken about.



> From: Leif Mortenson <leif@ta...>
>
=EF=BF=BC Re: getting hardware arch using just java
> 2006-06-07 00:54
>  David,
>      The files in the delta pack can be deleted as you wish, or even
>  added if you have
>  compiled the wrapper for other platforms.   In general, the
>  wrapper-xx-xx-64 files
>  are not really needed as the 32 bit versions work fine on the 64 bit
>  platforms.
>  The libwrapper-xx-xx-64.so files are required if a 64 bit JVM is =20
> being
>  used.  The
>  32.so files are used by 32 bit JVMs regardless of whether the =20
> hardware
>  is 32 or
>  64 bits.
>
>  Cheers,
>  Leif
>
>  David Ferrero wrote:
>  > If I want the wrapper scripts to detect the proper architecture
>  > native libs to use, and I want to minimize the installation size of
>  > my software, can I have my installer script install just the OS =20
> bits
>  > for a given OS instead of the whole delta-pack?
>  >
>  > ie:
>  >
>  > For os.name=3D"Linux", could I have my Installer just copy the =
Linux
>  > scripts plus the following files?
>  > lib/wrapper.jar
>  > lib/libwrapper-linux-ppc-64.so
>  > lib/libwrapper-linux-x86-32.so
>  > lib/libwrapper-linux-x86-64.so
>  >
>  > Thanks for clarifying,
>  >
>  > David
>  >