import java.util.concurrent.*;

public class TestExchanger {
    public static void main(String[] args) {
        Exchanger<String> exchanger = new Exchanger<>();
        ExecutorService executor = Executors.newCachedThreadPool();
        executor.execute(new ExchangeThread(exchanger, "dog"));
        executor.execute(new ExchangeThread(exchanger, "cat"));
        executor.shutdown();
    }
}

class ExchangeThread extends Thread {
    private Exchanger<String> exchanger;
    private String obj;

    ExchangeThread(Exchanger<String> exchanger, String obj) {
        this.exchanger = exchanger;
        this.obj = obj;
    }

    @Override
    public void run() {
        try {
            System.out.println("Give " + obj + " and get " + exchanger.exchange(obj));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}