Is there a way to get/hook/attach an already running process using java?

Question

I want to be able to do something like that:

Process p  = getRunningProcess(pid)

If there's a way, does it matter how the process was created (using java, using python, from the shell, etc...)?

Answer 1

It is possible to attach to another JVM process from Java app (e.g. to be able to monitor what's going on and potentially detect problems before they happen). You can do this by using the Attach API. Don't know much about attaching to non-JVM processes.

String name = ...
List vms = VirtualMachine.list();
for (VirtualMachineDescriptor vmd: vms) {
    if (vmd.displayName().equals(name)) {
        VirtualMachine vm = VirtualMachine.attach(vmd.id());
        String agent = ...
        vm.loadAgent(agent);
        // ...
    }
}