How to open the command prompt and insert commands using Java?

If you are running two commands at once just to change the directory the command prompt runs in, there is an overload for the Runtime.exec method that lets you specify the current working directory. Like,

Runtime rt = Runtime.getRuntime();
rt.exec("cmd.exe /c start command", null, new File(newDir));

This will open command prompt in the directory at newDir. I think your solution works as well, but this keeps your command string or array a little cleaner.

There is an overload for having the command as a string and having the command as a String array.

You may find it even easier, though, to use the ProcessBuilder, which has a directory method to set your current working directory.

Hope this helps.

I know that people recommend staying away from rt.exec(String), but this works, and I don't know how to change it into the array version.

rt.exec("cmd.exe /c cd \""+new_dir+"\" & start cmd.exe /k \"java -flag -flag -cp terminal-based-program.jar\"");

public static void main(String[] args) {
    try {
        String ss = null;
        Process p = Runtime.getRuntime().exec("cmd.exe /c start dir ");
        BufferedWriter writeer = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
        writeer.write("dir");
        writeer.flush();
        BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
        BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
        System.out.println("Here is the standard output of the command:\n");
        while ((ss = stdInput.readLine()) != null) {
            System.out.println(ss);
        }
        System.out.println("Here is the standard error of the command (if any):\n");
        while ((ss = stdError.readLine()) != null) {
            System.out.println(ss);
        }

    } catch (IOException e) {
        System.out.println("FROM CATCH" + e.toString());
    }

}