Usage of -d32 and -d64 while launching Java

Question

I read below excerpt from JDK FAQ\'s

How do I select between 32 and 64-bit operation? What\'s the default? The options -d32 and -d64 have been added to

Answer 1

The citation you made:

The options -d32 and -d64 have been added to the Java launcher to specify whether the program is to be run in a 32 or 64-bit environment.

is valid only for the Solaris operating system.

Later in the JDK's FAQ, we can read:

All other platforms (Windows and Linux) contain separate 32 and 64-bit installation packages. If both packages are installed on a system, you select one or the other by adding the appropriate "bin" directory to your path. For consistency, the Java implementations on Linux accept the -d64 option.

So to answer your second question, in Windows and in Linux, theses flags are useless and the 32/64 bit selection is done by running the corresponding JVM installation.