等待命令行线程完成并以正确的方式退出

Question

I´ve got a problem exiting a thread in the right way. I adapted some code that helps me running a executable in a Commandline window from my code. Until this the code works fine. The problem is that after the program that I´m calling is finished and returns to command line, one thread keeps running, How do I get the information which one is finished and how do I kill it afterwards properly? I already tried several options with wait and notify but I couldn´t get them to work. Thanks for the help, that´s my code:

public class InnExec {

    String wkdir;
    static String ActCommand;
    static String InFile;



    InnExec(String wkdir, String ActCommand, String InFile) {
        InnExec.ActCommand=ActCommand;
        this.wkdir=wkdir;
        InnExec.InFile=InFile;
    }
    public Process Run() throws IOException, InterruptedException {
    File wkdir=new File(this.wkdir);


    ProcessBuilder processBuilder= new ProcessBuilder();
    Boolean Windows=true;
    if (!System.getProperty("os.name").contains("Windows")){
        Windows=false;
    }
    if(Windows){
        processBuilder.command("cmd.exe").redirectErrorStream(true);
    }
    else{
        processBuilder.command("/bin/bash").redirectErrorStream(true);
    }
    processBuilder.directory(wkdir);
      Process process = processBuilder.start();
      Thread processOutputHandlerThread=createAndStartProcessOutputHandlerThread(process);
      Thread processInputHandlerThread =createAndStartProcessInputHandlerThread(process);

  return process;



    }
    private static Thread createAndStartProcessInputHandlerThread(final Process process) {
        Thread thread = new Thread(new Runnable() {
          public void run() {
            PrintWriter printWriter = new PrintWriter(process.getOutputStream());
            //Scanner scanner = new Scanner(System.in);
            try {
                printWriter.println(ActCommand+"<"+InFile);
                printWriter.flush();
               Thread.sleep(50);
              }
             catch (InterruptedException interruptedException) {
                 //
            }

          }
        });
        thread.start();

        return thread;
      }



    private static Thread createAndStartProcessOutputHandlerThread(final Process process) {
        Thread thread = new Thread(new Runnable() {
          public void run() {
            try {

              char c = Character.MAX_VALUE;
              while ((c = (char) process.getInputStream().read()) != Character.MAX_VALUE) {
                  System.out.print(c);

               // Ausgabe auf Java Console

              }

            } catch (IOException e) {
              e.printStackTrace();
            }

          }

        });
        thread.start();

        return thread;
      }



}

Answer 1

You could use CountDownLatch

In your main method, you could define how many threads you would have, inject it within each of your threads and wait for their completion. Once a thread completes, its would call countdown api and once all your thread completes, your main method can continue further.