Issue in calling Python code from Java (without using jython)

JavaYouth :

I found this as one of the ways to run (using exec() method) python script from java. I have one simple print statement in python file. However, my program is doing nothing when I run it. It neither prints the statement written in python file nor throws an exception. The program just terminates doing nothing:

Process p = Runtime.getRuntime().exec("C:\\Python\\Python36-32\\python.exe C:\\test2.py");

Even this is not creating the output file:

Process p = Runtime.getRuntime().exec("C:\\Python\\Python36-32\\python.exe C:\\test2.py output.txt 2>&1");

What is the issue?

Patrick :

I think you could try your luck with the ProcessBuilder class.

If I read the Oracle documentation correctly, the std inputs and outputs are directed to pipes by default but the ProcessBuilder has an easy method for you to explicitly set output (or input) to a file on your system or something else.

If you want your Python program to use the same output as your Java program (likely stdout and stderr), you can use stg like this:

ProcessBuilder pb = new ProcessBuilder("C:\\Python\\Python36-32\\python.exe", "C:\\test2.py");
pb.redirectOutput(Redirect.INHERIT);
Process p = pb.start();