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

For Windows, you can check the Java home location. If it contains (x86) it is 32-bit otherwise 64-bit:

public static boolean is32Bit()
{
    val javaHome = System.getProperty("java.home");
    return javaHome.contains("(x86)");
}

public static boolean is64Bit()
{
    return !is32Bit();
}

Example paths:

C:\Program Files (x86)\Java\jdk1.8.0_181\bin\java.exe # 32-bit
C:\Program Files\Java\jdk-10.0.2\bin\java.exe # 64-bit

Why care about a Windows only solution?

If you need to know which bit version you're running on, you're likely fiddling around with native code on Windows so platform-independence is out of the window anyway.