How can I tell if I'm running in 64-bit JVM or 32-bit JVM (from within a program)?

Question

How can I tell if the JVM in which my application runs is 32 bit or 64-bit? Specifically, what functions or properties I can used to detect this within the program?

Answer 1

Under Windows 7 in the "Control Panel" under "Programs | Programs and Features" the 64-bit variants of JRE & JDK are listed with "64-bit" in parentheses (e.g. "Java SE Development Kit 7 Update 65 (64-Bit)"), while for the 32-bit variants the variant is not mentioned in parentheses (e.g. just "Java SE Development Kit 8 Update 60").