怎么充分利用多核CPU，计算很大的List中所有整数的和(转)

如何充分利用多核CPU，计算很大的List中所有整数的和(转)

public?class?CountSumWithCallable?{ ????????/** ??????*?@param?args ??????*?@throws?InterruptedException? ??????*?@throws?ExecutionException? ??????*/??????public?static?void?main(String[]?args)?throws?InterruptedException,?ExecutionException?{ ??????????int?threadCounts?=19;//使用的线程数 ??????????long?sum=0; ??????????ExecutorService?exec=Executors.newFixedThreadPool(threadCounts); ??????????List<Callable<Long>>?callList=new?ArrayList<Callable<Long>>(); ??????????//生成很大的List ??????????List<Integer>?list?=?new?ArrayList<Integer>(); ??????????for?(int?i?=?0;?i?<=?1000000;?i++)?{ ??????????????list.add(i); ??????????} ??????????int?len=list.size()/threadCounts;//平均分割List ??????????//List中的数量没有线程数多（很少存在） ??????????if(len==0){ ??????????????threadCounts=list.size();//采用一个线程处理List中的一个元素 ??????????????len=list.size()/threadCounts;//重新平均分割List ??????????} ??????????for(int?i=0;i<threadCounts;i++){ ??????????????final?List<Integer>?subList; ??????????????if(i==threadCounts-1){ ??????????????????subList=list.subList(i*len,list.size()); ??????????????}else{ ??????????????????subList=list.subList(i*len,?len*(i+1)>list.size()?list.size():len*(i+1)); ??????????????} ??????????????//采用匿名内部类实现 ??????????????callList.add(new?Callable<Long>(){ ??????????????????public?Long?call()?throws?Exception?{ ??????????????????????long?subSum=0L; ??????????????????????for(Integer?i:subList){ ??????????????????????????subSum+=i; ??????????????????????} ??????????????????????System.out.println("分配给线程："+Thread.currentThread().getName()+"那一部分List的整数和为：\tSubSum:"+subSum); ??????????????????????return?subSum; ??????????????????} ??????????????}); ??????????} ??????????List<Future<Long>>?futureList=exec.invokeAll(callList); ??????????for(Future<Long>?future:futureList){ ??????????????sum+=future.get(); ??????????} ??????????exec.shutdown(); ??????????System.out.println(sum); ??????} ????}??