I believe we can use ProcessBuilder

Runtime.getRuntime().exec("python "+cmd + py + ".py");
.....
//since exec has its own process we can use that
ProcessBuilder builder = new ProcessBuilder("python", py + ".py");
builder.directory(new File(cmd));
builder.redirectError();
....
Process newProcess = builder.start();

You can include the Jython library in your Java Project. You can download the source code from the Jython project itself.

Jython does offers support for JSR-223 which basically lets you run a Python script from Java.

You can use a ScriptContext to configure where you want to send your output of the execution.

For instance, let's suppose you have the following Python script in a file named numbers.py:

for i in range(1,10):
    print(i)

So, you can run it from Java as follows:

public static void main(String[] args) throws ScriptException, IOException {

    StringWriter writer = new StringWriter(); //ouput will be stored here
    
    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptContext context = new SimpleScriptContext();
    
    context.setWriter(writer); //configures output redirection
    ScriptEngine engine = manager.getEngineByName("python");
    engine.eval(new FileReader("numbers.py"), context);
    System.out.println(writer.toString()); 
}

And the output will be:

1
2
3
4
5
6
7
8
9

As long as your Python script is compatible with Python 2.5 you will not have any problems running this with Jython.

You are not checking for errors from the python script. You can achieve this simply by merging STDERR to STDOUT and reporting the content of STDOUT to console:

Process p = new ProcessBuilder("python", "Refresh.py")
            .redirectErrorStream(true)
            .start();
p.getInputStream().transferTo(System.out);
int rc = p.waitFor();

This should print out the error message from python and give you error code back. You may have problems with path to files, so you might need to adjust your arguments to explicit pathnames to "python" and/or "Refresh.py".

Assuming the script is in the jar file, you can get an input stream from the resource, and use it as the input to a Process created from the python interpreter:

// Note: the path to the script here is relative to the current class
// and follows strict resource name rules, since this is in a jar file
InputStream script = getClass().getResourceAsStream("visualize3D.py");

// The following creates a process to run python3.
// This assumes python3 is on the system path. Provide the full
// path to the python3 interpreter (e.g. /usr/bin/python3) if it's
// not on the path.

// The - option to python3 instructs it to execute a script provided
// as standard input.

Process process = new ProcessBuilder("python3", "-")
    .start() ;
OutputStream out = process.getOutputStream();
byte[] buffer = new byte[1024];
int read = 0;
while((read = script.read(buffer)) != -1) {
    pos.write(buffer, 0, read);
}
script.close();

For details on getting the correct path for the script, see How do I determine the correct path for FXML files, CSS files, Images, and other resources needed by my JavaFX Application?