How can I from within Java code find out which and how the running JVM was launched? My code shall spawn another Java process hence I'd be especially interested in the first parameter - which usually (in C, Pascal, Bash, Python, ...) points to the currently running executable.

Edit: I am not sure why someone would downvote - but maybe I was not clear enough for others.

So when a java application is run like

d:\openjdk\bin\java -Xmx500g -Dprop=name -jar my.jar param1 param2

I can access command line parameters in my main method like

public class Main {
    public static void main(String[] args) {
        System.out.println("main called with "   args);
    }
}

but that will deliver access to param1 and param2 only. How would I get the full command line?

CodePudding user response：

Following Determining location of JVM executable during runtime I found the real answer to be:

ProcessHandle.current().info().commandLine().orElseThrow();

Thank you, @XtremeBaumer

CodePudding user response：

Use the Runtime Management Bean RuntimeMXBean to obtain the VM arguments, like in:

RuntimeMXBean mxBean = ManagementFactory.getRuntimeMXBean();
List<String> inputArgs = mxBean.getInputArguments();

This will return all arguments passed to the virtual machine, not the parameters passed to the main method.

To get the command, use ProcessHandle as answered here by Hiran Chaudhuri.