32 or 64

[don]

For purposes of Java development is it better to have both the 32 and 64
bit versions of the SDK installed, or only one of them?
Some programs require the 32 bit and some come in a version for each, like
eclipse. When x64 Java first became available I began using it but found
that some programs, like Vuze, required the 32 bit version.
It seems odd that you would need 2 versions of the SDK and JVM installed on
a machine. I¢d like to eliminate one of them but it seems that means the 32
bit would be the one to use since it¢s probably the most compatible. And
that seems like moving backwards.

 

[Jeff Higgins]

For purposes of Java development is it better to have both the 32 and 64
bit versions of the SDK installed, or only one of them?
Some programs require the 32 bit and some come in a version for each, like
eclipse. When x64 Java first became available I began using it but found
that some programs, like Vuze, required the 32 bit version.
It seems odd that you would need 2 versions of the SDK and JVM installed on
a machine. I¢d like to eliminate one of them but it seems that means the 32
bit would be the one to use since it¢s probably the most compatible. And
that seems like moving backwards.

Are all of your questions following this?
<http://www.oracle.com/technetwork/java/hotspotfaq-138619.html#64bit_description>

 

[don]

For purposes of Java development is it better to have both the 32 and 64
bit versions of the SDK installed, or only one of them?
Some programs require the 32 bit and some come in a version for each, like
eclipse. When x64 Java first became available I began using it but found
that some programs, like Vuze, required the 32 bit version.
It seems odd that you would need 2 versions of the SDK and JVM installed on
a machine. I¢d like to eliminate one of them but it seems that means the 32
bit would be the one to use since it¢s probably the most compatible. And
that seems like moving backwards.

One more thing occurred to me after my original post: Isn¢t it desirable
that the transition from 32 to 64 bit Java should eventually replace and
obsolete the 32 bit version?
For instance, from the point of view of market acceptance, in light of all
the other obstacles that exist, does it really make sense to require users
to have installed two versions of the Java VM?

 

[Eric Sosman]

Java code will run just fine on either a 32-bit or 64-bit
JVM -- or on a 23-bit or 107-bit JVM, should such beasts ever
evolve. It's true that a memory-hungry Java application may
need more space than a 32-bit JVM can provide and in that sense
require a 64-bit (or "greater-than-34-bit") JVM. Going the other
way, though, is no problem: If a piece of Java code can run in
a 32-bit JVM, it can also run in a 64-bit JVM.

Note that I said "Java code." When you step outside Java
itself (with JNI, for example), configuration issues can become
thornier. If your Java code calls upon a native library that
exists only in an X-bit version, then you must run an X-bit JVM
for the library's sake. I'm not acquainted with Vuze, but it
seems likely something of that sort is at the root of your problem.
If so, your complaint is not with Java but with the Born Vuzers:
Your difficulties arise from their reluctance to write a pure Java
application and/or to supply suitable versions of the non-Java bits.
(Let me repeat: I am not acquainted with Vuze, and am only guessing
about the reasons for its 32-bit chauvinism -- Still, I'm moderately
confident in my guesswork.)

One more thing occurred to me after my original post: Isn¢t it desirable
that the transition from 32 to 64 bit Java should eventually replace and
obsolete the 32 bit version?

For servers, I'd imagine 32-bit will fade out. Probably for
desktops, too, albeit more slowly. For set-top boxes, E-wallets,
toasters, alarm system components, ... No. (For browsers -- Well,
who's daft enough to enable Java in an Internet browser?)

For instance, from the point of view of market acceptance, in light of all
the other obstacles that exist, does it really make sense to require users
to have installed two versions of the Java VM?

Again, I strongly suspect that the requirement originates
outside of Java.

 

[Lew]

Depends.

I have both installed, but I have not used the 32-bit version on a 64-bit
computer in years.

Which ones require the 32-bit version? No Java program, for sure.

eclipse [sic]. When x64 Java first became available I began using it butfound
that some programs, like Vuze, required the 32 bit version.

And yet they include a 64-bit JAR for the SWT part, which contains native code.
Hmm. Could you be mistaken?

There's nothing in the Vuze documentation that limits it to using 32-bit Java.

Especially since you don't.

They're equally compatible. Java bytecode doesn't change for 64-bit vs. 32-bit.

The operative word being "seems" since the premise is false.

One more thing occurred to me after my original post: Isn’t it desirable
that the transition from 32 to 64 bit Java should eventually replace and
obsolete the 32 bit version?

No, since one doesn't render the other obsolete.

For instance, from the point of view of market acceptance, in light of all
the other obstacles that exist, does it really make sense to require users
to have installed two versions of the Java VM?

No, but then no one does.

What other obstacles? Java is arguably the most widely accepted programming
language right now. Certainly it's up there.

Facts not in evidence, premise of the question not valid, there is no
meaningful answer.

 

[don]

Depends.

I have both installed, but I have not used the 32-bit version on a 64-bit
computer in years.

Which ones require the 32-bit version? No Java program, for sure.

eclipse [sic]. When x64 Java first became available I began using it but found
that some programs, like Vuze, required the 32 bit version.

And yet they include a 64-bit JAR for the SWT part, which contains native code.
Hmm. Could you be mistaken?

Perhaps more recent versions will run with 64 bit Java. As of two or so
years ago they didn't

There's nothing in the Vuze documentation that limits it to using 32-bit Java.


Especially since you don't.


They're equally compatible. Java bytecode doesn't change for 64-bit vs. 32-bit.


The operative word being "seems" since the premise is false.


No, since one doesn't render the other obsolete.


No, but then no one does.

What other obstacles? Java is arguably the most widely accepted programming
language right now. Certainly it's up there.

Facts not in evidence, premise of the question not valid, there is no
meaningful answer.

Uh OK.

I don't mean to split hairs but in my experience 32 bit versions of eclipse
required a 32 bit JVM. Likewise Vuze. 32 bit Firefox requires a 32 bit JVM
to run applets. I don't have much of a list because it consists only of
those programs which I use or have used and my recollections of them.
Certainly there have been enough of these for me to know that, of programs
which require Java to run, some of them require 32 bit JVM's and some 64.
Is this really a point of contention?

 

[Lew]

I don't mean to split hairs but in my experience 32 bit versions of eclipse

You have it backwards. The 32-bit version of Eclipse is for when you have the
a 32-bit system. Why would you install it on a 64-bit system?

Of course if you install a 32-bit program you will need to run 32-bit programs
with it. But your complaint was that somehow Oracle was forcing you to do that.
So far only you are forcing you to do that.

required a 32 bit JVM. Likewise Vuze. 32 bit Firefox requires a 32 bit JVM

Ditto and ditto. Both of those come in 64-bit versions. In neither case is
Oracle the one forcing you to install both 32- and 64-bit versions of things.

It is your own choice to use 32-bit software outside of Java, then trying to
use Java that works with them, that forces you to use 32-bit Java.

to run applets. I don't have much of a list because it consists only of
those programs which I use or have used and my recollections of them.

But why didn't you use the 64-bit versions of these programs?

Certainly there have been enough of these for me to know that, of programs
which require Java to run, some of them require 32 bit JVM's and some 64.
Is this really a point of contention?

If you make it one, it is.

Your complaint is that it was Java's fault. It wasn't, It was your insistence
on using 32-bit software that caused it. If that's the only software you use
that hooks into Java, then you didn't need the 64-bit version. Either way, as
far as Java's concerned you only need one version.

By the way, the difference in these products between the 32- and 64-bit
isn't in the Java, as you seem to think, it's in the native code.

Yet another layer of why your complaint with Oracle or Java is misplaced.

So to your original post:

Isn’t it desirable that the transition from 32 to 64 bit Java should
eventually replace and obsolete the 32 bit version?

No. There is no such transition, so your question makes no sense.

32-bit and 64-bit Java operate in different environments. If you mix the
environments then you mix the needs, but that's not Java's fault. The two
versions are not replacements for each other, but versions targeted for
different platforms.

Your question makes as much sense as asking if the Macintosh version of Java
shouldn't replace the Windows version.

For instance, from the point of view of market acceptance, in light of all
the other obstacles that exist, does it really make sense to require users
to have installed two versions of the Java VM?

No. So why did you require that?

 

[Roedy Green]

For purposes of Java development is it better to have both the 32 and 64
bit versions of the SDK installed, or only one of them?

you need a 64-bit JDK and a 32-bit JRE so that 32- bit browsers can
run applets.