ExecutorService executor = Executors.newFixedThreadPool(3); //Executors.newCachedThreadPool();

 

package com.inte.fork;

/**
 * Created on 2016/4/20.
 */

import java.util.*;
import java.util.concurrent.*;

import static java.util.Arrays.asList;

public class Sums {

    static class Sum implements Callable<Long> {
        private final long from;
        private final long to;

        Sum(long from, long to) {
            this.from = from;
            this.to = to;
        }

        @Override
        public Long call() {
            long acc = 0;
            for (long i = from; i <= to; i++) {
                acc = acc + i;
            }
            System.out.println(Thread.currentThread().getName() + " : " + acc);
            return acc;
        }
    }

    public static void main(String[] args) throws Exception {
        ExecutorService executor = 
Executors.newFixedThreadPool(3);
/*
pool-1-thread-2 : 5050
pool-1-thread-1 : 55
pool-1-thread-3 : 500500
pool-1-thread-3 : 500000500000
55
5050
500500
500000500000
*/
        
//Executors.newCachedThreadPool(); 
/*
pool-1-thread-1 : 55
pool-1-thread-3 : 500500
pool-1-thread-2 : 5050
pool-1-thread-4 : 500000500000
55
5050
500500
500000500000
*/
        List<Future<Long>> results = executor.invokeAll(asList(
                new Sum(0, 10), new Sum(0, 100),new Sum(0, 1_000), new Sum(0, 1_000_000)
        ));
        executor.shutdown();

        for (Future<Long> result : results) {
            System.out.println(result.get());
        }
    }
}