package threads;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class MyRunnable implements Runnable {
    private int var;
    public volatile boolean shutdown;

    public MyRunnable(int var) {
        this.var = var;
    }

    @Override
    public void run() {
        try {
            while (!Thread.currentThread().isInterrupted()) {
                String cmd = "gedit";
                Process proc = Runtime.getRuntime().exec(cmd);
                System.out.println("Command executed");
                String line;
                try (BufferedReader input = new BufferedReader(new InputStreamReader(proc.getInputStream()))) {
                    while ((line = input.readLine()) != null) {
                        System.out.println(line);
                    }
                }
                BufferedReader stdError = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
                String s = null;
                // read any errors from the attempted command
                System.out.println("Here is the standard error of the command (if any):n");
                while ((s = stdError.readLine()) != null) {
                    System.out.println(s);
                }
            }
        } catch (Exception e) {
            System.err.println("gedit error : " + e.getLocalizedMessage());
        }
    }
}

package threads;

public class Threads {
    /**
     * @param args the command line arguments
     * @throws java.lang.InterruptedException
     */
    public static void main(String[] args) throws InterruptedException {
        MyRunnable myRunnable = new MyRunnable(0);
        Thread t = new Thread(myRunnable);
        System.out.println("t.getState 1 : " + t.getState());
        t.start();
        Thread.sleep(2000);
        t.interrupt();
        System.out.println("t.getState 2 : " + t.getState());
        }
    }

public class Executor {

  private Process process;
  private final String command;

  Executor(String command) {
    this.command = command;
  }

  public void run() throws Exception {

    process = Runtime.getRuntime().exec(command);
    System.out.println("Command executed");

    Thread runner = new Thread(() -> {
        try {
            try (BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
                String line;
                while (process.isAlive() && (line = input.readLine()) != null)
                    System.out.println(line);
            }


            //небольшая задержка, т.к. иногда не успевает проставиться флаг
            TimeUnit.MILLISECONDS.sleep(100);
            if (!process.isAlive()) {
                System.out.println("process " + command + " has been stopped!");
                return;
            }

            // read any errors from the attempted command
            System.out.println("Here is the standard error of the command (if any):n");
            try (BufferedReader stdError = new BufferedReader(new InputStreamReader(process.getErrorStream()))) {
                String errorCode;
                while (process.isAlive() && (errorCode = stdError.readLine()) != null)
                    System.out.println(errorCode);
            }

        } catch (Exception e) {
            System.err.println(command + " error : " + e.getLocalizedMessage());
        }
    });

    runner.start();
  }

  public void shutdown() {
    process.destroy();
  }
}

Executor process = new Executor("pluma");
//запуск
process.run();
//остановка
process.shutdown();