Forcing 64 bit jvm to 32 bit jvm?

Question

Would anyone please give me ideas about forcing 64 bit jvm to run as 32-bit jvm?

I need to write a jse desktop application for bluetooth connection. For that i need to implement Bluecove jar . It has 32-bit files only. So i included -D32 under VM arguments in eclipse pulsar. But still i am getting the same error that displayed before adding the argument: bluecove_x64.dll missing. I tried with -d32, and it showed me "unrecognized option: d32".

And it seems like i should install a 32-bit jvm that would run on 64-bit os. So, can anyone please tell me what exactly should i install? Java SDK in 32-bit or Eclipse software?

Thanks in advance!

Aube

Answer 1

Switching modes is only possible on Solaris. A JVM is either 64bit or 32bit, except on Solaris where both run modes are available in a single JVM.

But anyway, if you don't need more than 4Gig Ram, install the 32bit JVM also on 64bit Systems, because it is 10-15% faster and needs less memory.

Thither

32bit VMs can't access the full 4GB address space AFAIR. – Talya

Installing 32-bit vm means i should install eclipse software 32-bit only, right? – Aube

Anu: No, you can safely develop with Eclipse 64bit, using a 64bit JVM. But from Eclipse, start your app with the 32bit JVM. The compiler remains the same, bytecode does not care for the bits. – Thither

Ok, Which means i should force the jvm by including -d32 in vm arguments, ryt? But it is not working. Any suggestions, please? – Aube

you CANNOT force the JVM to use a mode. You have to INSTALL the right JVM (and then just use it). – Thither

@Heiko, that is a Windows limitation – Weeds

Answer 2

First, install a 32-bit JVM. (I suppose this is under Windows).

Then in Eclipse, open the Preferences panel, and go to Java -> Installed JRE's.

Click Search, tell it to search your harddisk.

Wait.

You should now see both your original 64-bit JVM and your new 32-bit JVM in the list. Put the checkmark on the 32-bit JVM instead of the 64-bit JVM. Click OK.

You should now use a 32-bit JVM in Eclipse, which should be compatible with the library you have.

Swig