Unable to execute Runtime.getRuntime().exec(

Question

Hello,
I am new to Java programming and trying to execute (OS is Linux) an external jar File with the command:
Runtime.getRuntime().exec("nohup java -jar SeismicAgents.jar &");It should start the SeismicAgents.jar and write the output to nohup.out.
This works perfectly if I just enter the command at the command line.
But upon starting it from within my program, the process seems to be started (I can see it when executin "ps aux"), but it is obviously not running as no input is written to nohup.out and the file which SeismicAgents.jar should generate is not generated.
I also tried the following code:
String cmd[] = {"nohup", "java", "-jar", "SeismicAgents.jar", "&"};
Runtime.getRuntime().exec(cmd);But I am experiencing the same problem here.
Executing something like
Runtime.getRuntime().exec(ls);works without problems...
Can anyone help?

Answer 1

Runtime.getRuntime().exec("nohup java -jar
SeismicAgents.jar &");Java does not interprete the '&' character. Neither does
nohup. You would have to prefix this with /bin/sh -c, put
the rest in quotes and, most importantly, redirect input
and output somewhere. Without redirection, it is the task
of your java program to feed the subprocess with input
and drain its stdout and stderr buffers.
Executing something like
Runtime.getRuntime().exec(ls);works without problems...It is hard to believe this. Either it should be "ls" or
ls is string variable containing the relevant string,
but even then I would be surprised if you see any
output on the command line. At least I don't get
anything with public class bla {
  public static void main(String[] argv) throws Exception {
    Runtime.getRuntime().exec("ls");
}If you don't want a "/bin/sh -c" hack, you may want to
try http://www.ebi.ac.uk/~kirsch/monq-doc/monq/stuff/Exec.html .
Harald.