Java ProcessBuilder doesn't work within a Thread

Question

I am using Java ProcessBuilder to execute two shell scripts. I want to have a 10 seconds time gap between two executions. So that's why I am using Threads. But following code doesn't execute shell scripts( without threads they execute).

public void execute() {

    new Thread(new Runnable() {
        public void run() {
            Process process_1;
            try {

                List<String> cmdList_1 = new ArrayList<String>();

                cmdList_1.add("sh");
                cmdList_1.add("command_1.sh");
                ProcessBuilder pb = new ProcessBuilder(cmdList_1);
                process_1 = pb.start();
                process_1.waitFor();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }).start();

    new Thread(new Runnable() {
        public void run() {
            Process process_2;
            try {
                Thread.sleep(10000);

                List<String> cmdList_2 = new ArrayList<String>();

                cmdList_2.add("sh");
                cmdList_2.add("command_2.sh");
                ProcessBuilder pb = new ProcessBuilder(cmdList_2);
                process_2 = pb.start();
                process_2.waitFor();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }).start();
}  

How can I fix my code ? or are there any better way to fulfill my ambition?

Thanks in advance

Answer 1

Try consuming the output from the process, something like this:

ProcessBuilder processBuilder = new ProcessBuilder();
Process process = processBuilder.start();
BufferedReader reader = new BufferedReader((new InputStreamReader(process.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
    System.out.println(line);
}