java runtime exec get output

1private static void execCommand() {
2  String[] command = {"echo", "Hello", "world."};
3  
4  new Thread(() -> {
5    try {
6      ProcessBuilder builder = new ProcessBuilder(command);
7      builder.redirectErrorStream(true);
8      final Process proc = builder.start();
9      BufferedReader in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
10      String s = null;
11      while ((s = in.readLine()) != null) {
12        System.out.println(s);
13      }
14    } catch (IOException e) {
15      e.printStackTrace();
16    }
17  }).start();
18}

1private static void GetOutput(final Process process) {
2    new Thread() {
3        public void run() {
4            BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
5            String line = null; 
6            try {
7                while ((line = input.readLine()) != null) {
8                    System.out.println(line);
9                }
10            } catch (IOException e) {
11                e.printStackTrace();
12            }
13        }
14    }.start();
15}