How do I detect which kind of JRE is installed — 32bit vs. 64bit

Question

During installation with an NSIS installer, I need to check which JRE (32bit vs 64bit) is installed on a system. I already know that I can check a system property \"su

Answer 1

When writing Java code, how do I distinguish between 32 and 64-bit operation?

http://www.oracle.com/technetwork/java/hotspotfaq-138619.html#64bit_detection

There's no public API that allows you to distinguish between 32 and 64-bit operation. Think of 64-bit as just another platform in the write once, run anywhere tradition. However, if you'd like to write code which is platform specific (shame on you), the system property sun.arch.data.model has the value "32", "64", or "unknown".