There are times that you login to a server with an already installed
JDK and you have to know if this is a 32-bit or a 64-bit JDK.
My recommended procedure to find it out is to run in a CLI this command: $> java -d64 -version
You can run this command on 32-bit and 64-bit JDKs, but it produces different result, where you can understand which kind of JDK you are using.
Here is a sample output:
32-bit JDK
$java -d64 -version Running a 64-bit JVM is not supported on this platform
64-bit JDK
$java -d64 -version java version "1.6.0_31" Java(TM) SE Runtime Environment (build 1.6.0_31-b05) Oracle JRockit(R) (build R28.2.3-13-149708-1.6.0_31-20120327-1523-linux-x86_64, compiled mode)
When you running it on a 32-bit JDK, the command is not supported, so you get an error message. While when running it on 64-bit JDK you get the information of the installed JDK.
This method works both with HotSpot and JRockit JVMs, but it is only supported on Linux and Solaris.
My recommended procedure to find it out is to run in a CLI this command: $> java -d64 -version
You can run this command on 32-bit and 64-bit JDKs, but it produces different result, where you can understand which kind of JDK you are using.
Here is a sample output:
32-bit JDK
$java -d64 -version Running a 64-bit JVM is not supported on this platform
$java -d64 -version java version "1.6.0_31" Java(TM) SE Runtime Environment (build 1.6.0_31-b05) Oracle JRockit(R) (build R28.2.3-13-149708-1.6.0_31-20120327-1523-linux-x86_64, compiled mode)
When you running it on a 32-bit JDK, the command is not supported, so you get an error message. While when running it on 64-bit JDK you get the information of the installed JDK.
This method works both with HotSpot and JRockit JVMs, but it is only supported on Linux and Solaris.