Issue with ProcessBuilder to start a shell script and pass argument from String

Question

I have a ProcessBuilder that executes a shell script, it worked fine until I wanted to add an argument to the shell script from a variable. It should execute like this: ./test.sh testarg - I am although getting a Null Pointer Exception:

Exception in thread "main" java.lang.NullPointerException
        at testOne.main(testOne.java:10)

---

Line 9:

String myarg = "testarg";

Line 10 (the one that gives me the error):

final ProcessBuilder processBuilder = new ProcessBuilder("/bin/bash", "-c",
        testOne.class.getResource("/test.sh " + myarg).getPath());

Had it like this before and it was working:

final ProcessBuilder processBuilder = new ProcessBuilder("/bin/bash", "-c",
        testOne.class.getResource("/test.sh").getPath());

I understand that I have have concatenated the /test.sh with the String and that it would be treated as filename now which is why it gives me the error. I can see the difference between between "/test.sh" and "/test.sh" + myarg and that it result in a invalid resource name. I do however not know how I could make it work so it executes test.sh with one argument that I set with the String.

Answer 1

Have you tried:

URL url = testOne.class.getResource("/test.sh");

if (url == null) {
    throw new Exception("Cannot find /test.sh");
}

final ProcessBuilder processBuilder = new ProcessBuilder("/bin/bash", "-c",
    url.getPath() + " " + myarg);