Running python file in cmd through java- %1 is not a valid Win32 application

Question

I am trying to execute python code with java. My code:

public class PyTest {
 public static void main(String[] args) {
 Runtime.getRuntime().exec("python src\\gui.py");
 }
}

Stack trace: Exception in thread "main" java.io.IOException: Cannot run program "src\gui.py": CreateProcess error=193, %1 is not a valid Win32 application

I know, that this error is present while executing python code with 32-bit version interpreter on 64-bit machine. However on my 64-bit machine are installed only 64-bit versions of python.

Answer 1

It is the command shell that knows how to run files by file extension, so you need to invoke the cmd.exe Windows shell program:

Runtime.getRuntime().exec("cmd.exe /c python src\\gui.py");

As the javadoc of exec says, the preferred way to run commands is ProcessBuilder, so your code should be:

new ProcessBuilder("cmd.exe", "/c", "python", "src\\gui.py").start();

You can even change the working directory with that:

new ProcessBuilder("cmd.exe", "/c", "python", "gui.py")
 .directory(new File("src"))
 .start();