java代码执行linux命令

try {
    ProcessBuilder pb = new ProcessBuilder("ls", "-l");
    Process process = pb.start();
    int exitCode = process.waitFor();
    if (exitCode != 0) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
        String line;
        while ((line = reader.readLine()) != null) {
            System.err.println(line);
        }
    }
} catch (IOException | InterruptedException e) {
    e.printStackTrace();
}

try {
    ProcessBuilder pb = new ProcessBuilder("ls", "-l");
    Process process = pb.start();
    BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
    int exitCode = process.waitFor();
    System.out.println("Exit Code: " + exitCode);
} catch (IOException | InterruptedException e) {
    e.printStackTrace();
}