What does -J stand for in the jvm argument -J-Xmx?

Question

What does -J stand for in the jvm argument -J-Xmx ? I have always used -Xmx only and it is the first time I have come across 'J'

Answer 1

The -J flag is used by a few command-line tools, themselves written in Java, to let you pass command-line arguments directly to the JVM they're running in. So, for example, you can't pass "-Xmx1000m" as an argument to javac.exe, but you can pass "-J-Xmx1000m", and javac.exe will (effectively) use it as an option to java.exe.