Java에서 시스템 명령을 어떻게 실행할 수 있습니까?

<code class="java">public class ImprovedCommandExecution {

    public static void main(String[] args) {
        try {
            Runtime r = Runtime.getRuntime();
            Process p = r.exec("uname -a");
            p.waitFor();
            BufferedReader b = new BufferedReader(new InputStreamReader(p.getInputStream()));

            StringBuilder output = new StringBuilder();
            String line;
            while ((line = b.readLine()) != null) {
                output.append(line).append("\n");
            }

            b.close();

            System.out.println(output);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}</code>