import java.util.concurrent.*;
public class CallableWorkerThread implements Callable<Integer> {
        private int workerNumber;

        CallableWorkerThread(int number) {
                workerNumber = number;
        }

        public Integer call() {
                for (int i=0;i<=100;i+=20) {
                        // Perform some work ...
                        System.out.println("Worker number: " + workerNumber + ", percent complete: " + i );
                        try {
                                Thread.sleep((int)(Math.random() * 1000));
                        } catch (InterruptedException e) {
                        }
                }
                return(workerNumber);
        }
}