How to check the jdk bit version (32bit or 64 bit)

[Vardan Negi]

Hi Guys,
I have a query regarding JDK bit version (64 bit or 32 bit). Not sure how to check the bit version in Windows, solaris and other O/S.

Output for java -version is as follows
java version "1.5.0_16"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_16-b02)
Java HotSpot(TM) Client VM (build 1.5.0_16-b02, mixed mode, sharing)

Please help.

Thanks,
Vardan.

[Rob Spoor]

Check System.getProperty("os.arch"). This will print out something like x86 for a 32 bit JVM. System.getProperty("sun.arch.data.model") also seems to be doing the job. But keep in mind, these (most likely) return the value for the JVM - a 32 bit JVM on a 64 bit OS will probably still be identified as 32 bit.

[Jesper de Jong]

The output that you show from java -version is from a 32-bit version. If it is 64-bit, you'll see something like "64-bit Server VM" in there instead of "Client VM".

[Niranjan Welankiwar]

You can try on the command line:

java -d64 -version

If it's not a 64-bit version, you'll get a message that looks like:

This Java instance does not support a 64-bit JVM. Please install the desired version.

[John Jai]

Niranjan Welankiwar wrote:You can try on the command line:

java -d64 -version

If it's not a 64-bit version, you'll get a message that looks like:

This Java instance does not support a 64-bit JVM. Please install the desired version.

When I tried on my 32 bit system I get following output. Not able to see quoted output "This Java instance does not support a 64-bit JVM. Please install the desired version."

C:\Documents and Settings\381422>java -d64 -version
Unrecognized option: -d64
Could not create the Java virtual machine.

C:\Documents and Settings\381422>java -d32 -version
Unrecognized option: -d32
Could not create the Java virtual machine.

[Rob Spoor]

Apparently this flag was added in Java 7. When I try it with a Java 6 JVM it fails, with a Java 7 JVM I get the specified output.

[Tulasi Kadali]

Hi Vardhan,

In solaris you can check whether java is 64bit by using the following command
================================================
#truss -t exec java -d64 -version

execve("/usr/jdk/instances/jdk1.5.0/bin/java", 0xFFBFFDDC, 0xFFBFFDEC)
argc = 3

execve("/usr/jdk/instances/jdk1.5.0/bin/sparcv9/java", 0x00031E18,
0x00032ADC)

argc = 2

java version "1.5.0_06"

Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)

Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_06-b05, mixed mode)
=============================================
The last line should give 64-Bit or 32-bit Java.

CHEERS,
RAMU KADALI

Vardan Negi wrote:Hi Guys,
I have a query regarding JDK bit version (64 bit or 32 bit). Not sure how to check the bit version in Windows, solaris and other O/S.

Output for java -version is as follows
java version "1.5.0_16"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_16-b02)
Java HotSpot(TM) Client VM (build 1.5.0_16-b02, mixed mode, sharing)

Please help.

Thanks,
Vardan.