Can Java execute batch file outside of current JVM in separate process tree

Question

Hi,
Does anyone know how to run programs from Java as separate processes that will not die when the spawning java program exits (JVM exits).
The problem I have with using Runtime.exec is it spawns only child processes under the current running JVM, thus when the origonal program that called Runtime.exec ends so does all child processes.
Basically I want to start a DOS batch file from my Java application, my Java application will then immediately exit (calling System.exit(0) ). The batch program will continue to run, its does some file clean up, create's some new files and deletes the old jar (containing the main app), it then rebuilds the main app jar and and executes the main class and then exits itself.
I've also tried the apache.tomcat.jni.Proc :-
long pool = Pool.create( new Long(0).longValue() );
long pa = Procattr.create( pool );
Procattr.dirSet( pa, "c:\\temp\\updater\\");
Procattr.cmdtypeSet( pa, Proc.APR_SHELLCM );
Procattr.detachSet( pa, 1 );
long proc = Proc.alloc( pool );
Proc.create( proc, "test.bat", new String[]{"test.bat"}, null, pa, pool );
System.exit(0);
The detach option doesn't work, if I take it off then the bat file runs and stops the JVM exiting, if I leave it in the batch file never gets called.
Is this possible in Java. Can java start master process on Windows XP JDK1.5+?
Cheers
Chris.

Answer 1

Well I found the answer elsewhere (java.net) thought I'd post it here for future visitors who might be experience the same problem.
Basically Runtime can do this however it must be done the following way :-
The java:-
public class Main {
    public static void main(String[] args) throws Exception {
        Process p=Runtime.getRuntime().exec("cmd /c c:\\test.bat");
        System.out.println("done");
        System.out.println("quitting");
        System.exit(0);
}The batch:-
@echo off
PING 1.1.1.1 -n 1 -w 5000 >nul
java -cp "c:\ " MainThe important line that makes the whole thing work is :-
@echo offIf this line is missing then the whole things locks up (must be the io streams getting used)
Also this code can not be run from an IDE (well at least not from Intellj) as it also locks up.
It must be run from a command prompt or jar.
Also note that any commands in the batch file must have there output redirected to "nul" otherwise Windows kills the cmd as soon as it trys to output to a dead stream (dead because the Java has exited). for example :-
@echo off
PING 1.1.1.1 -n 1 -w 10000 >nul
cd %1
del /F /Q *.* >nul
move /Y new\*.* >nul
RD /Q /S new >nul
PING 1.1.1.1 -n 1 -w 1000 >nul
java -cp "c:\ " Main
exit