import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class Esempio1 {

    public static void main(String[] args) {
        Runnable r = () -> System.out.println("Thread 1");

        ExecutorService executorService = Executors.newSingleThreadExecutor();
        executorService.execute(r);
        System.out.println("Main");
        executorService.shutdown();
        try {
            executorService.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
        } catch (InterruptedException e) { }
        
    }
}