This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Jesper Young wrote:If you are running Ubuntu, and you install Sun Java from the Ubuntu repository instead of installing it manually (by downloading it directly from Sun):
sudo apt-get install sun-java6-jdk Then you'll get the 64-bit version of Sun Java if your Ubuntu is also 64-bit.
That's nice to know, as finding the right one on the java.sun.com site is a pain.
I don't see a parallel for the JEE JDK/libaries, perhaps they are size agnostic?
I don't think there are Ubuntu packages for Java EE, but as far as I know Glassfish (Sun's Java EE reference implementation) is pure Java anyway, so there shouldn't be separate 32-bit and 64-bit versions.
One more way to check if you're installed JVM is 64-bit is to see if the "java" executable accepts the "-d64" option to specify the 64-bit data model.
If your JVM is 64-bit capable, it will accept either the "-d32" or the "-d64" option to select either the 32-bit or 64-bit data model respectively.
(Sample output taken from a 64-bit Debian install)
ssahmed@debian:[~]$ uname -a
Linux debian 2.6.26-2-amd64 #1 SMP Mon Oct 19 02:34:17 UTC 2009 x86_64 GNU/Linux
Usage: java [-options] class [args...]
(to execute a class)
or java [-options] -jar jarfile [args...]
(to execute a jar file)
where options include:
-d32 use a 32-bit data model if available
-d64 use a 64-bit data model if available
-server to select the "server" VM
The default VM is server.
<rest of output snipped>