using Runtime.exec() and the process exitValue = 1

[mike nu]

Hi there,

I am trying to use the Runtime.exec() to call another Java program, like this way:

Runtime runtime = Runtime.getRuntime();
Process process = null;

try{
process = runtime.exec("java mypackage.MyProgram");
}catch(Throwable t){
t.printStackTrace();
}
......

process.waitFor();
int exitValue = process.exitValue();

But MyProgram does not get executed, and the exitValue = 1

Can anyone tell me what does the exitValue = 1 mean? What's wrong with my code?

Thanks a lot.

Mike

[rahul V kumar]

Is it windows or Unix?

[mike nu]

It's suppose to work cross platforms, so both Windows and Unix.

[Stefan Wagner]

maximum intermediate question.

Did you try:

try
{
        process = runtime.exec ("/way/to/jdk/bin/java mypackage.MyProgram");
}
catch(Throwable t)
{
        t.printStackTrace();
}

which only solves finding the jdk, not the mypackage-location.

And did you think of

String [] params = null;
mypackage.MyProgram.main (params);

[mike nu]

Now I know that the return code of Process.exitValue() = 1, means that can not find the class.

Now the actuall error is:

java.lang.NoClassDefFoundError: my/pkg/MyProgram

MyProgram is in the same package of the parent process. Is there any trick in specifying the subprocess classpath?

[Stefan Wagner]

MyProgram is in the same package of the parent process. Is there any trick in specifying the subprocess classpath?

But it will not extend the environment (path, classpath, systemvariables) of the parent process!
There is no trick in specifying the classpath of the subprocess - only the common technique to specify it.

[Ulas Ergin]

maybe you should try Runtime.exec that takes a String[]as parameter ,