// concurrent/CountingTask.java // (c)2020 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. import java.util.concurrent.*; public class CountingTask implements Callable { final int id; public CountingTask(int id) { this.id = id; } @Override public Integer call() { Integer val = 0; for(int i = 0; i < 100; i++) val++; System.out.println(id + " " + Thread.currentThread().getName() + " " + val); return val; } }