parallelStream、CompletableFuture 使用默认ForkJoinPool.commonPool()线程池的问题

雨点打透心脏的1/2处 2021-08-30 18:15 908阅读 0赞

parallelStream和CompletableFuture  默认使用的都是 [ForkJoinPool.commonPool()][ForkJoinPool.commonPool] 默认线程池；

基于服务器内核的限制，如果你是八核，每次线程只能起八个，不能自定义线程池;

适用于对list密集计算操作充分利用CPU资源，如果需要调用远端服务不建议使用

public class StreamUtil {
    
        public static final int MAX_SEND = 50;
    
        public static <T> List<List<T>> splitList(List<T> list, int max_send) {
            int limit = (int) Math.ceil((double) list.size() / max_send);
            return Stream.iterate(0, n -> n + 1).limit(limit).parallel().map(i -> list.stream()
                    .skip(i * max_send).limit(max_send).parallel().collect(Collectors.toList()))
                    .collect(Collectors.toList());
        }
    }
    
    List<CompletableFuture> completableFutures = list.stream().map(fix -> CompletableFuture.runAsync(() -> {
                //todo
            },fixAssetPool)).collect(Collectors.toList());
    
            completableFutures.forEach(CompletableFuture::join);
    
    
    @Bean("fixAssetPool")
        public ThreadPoolTaskExecutor fixAssetPool(){
            ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
            executor.setCorePoolSize(10);
            executor.setMaxPoolSize(40);
            executor.setQueueCapacity(100);
            executor.setThreadNamePrefix("fixAssetPool-future-");
            executor.setRejectedExecutionHandler(new java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy());//设置拒绝策略
            return executor;
        }

参考：

[https://blog.csdn.net/z69183787/article/details/107026179][https_blog.csdn.net_z69183787_article_details_107026179]

[https://blog.csdn.net/z69183787/article/details/107025668][https_blog.csdn.net_z69183787_article_details_107025668]

[https://blog.csdn.net/z69183787/article/details/107026232][https_blog.csdn.net_z69183787_article_details_107026232]

[ForkJoinPool.commonPool]: https://mp.csdn.net/console/editor/html/107025668
[https_blog.csdn.net_z69183787_article_details_107026179]: https://blog.csdn.net/z69183787/article/details/107026179
[https_blog.csdn.net_z69183787_article_details_107025668]: https://blog.csdn.net/z69183787/article/details/107025668
[https_blog.csdn.net_z69183787_article_details_107026232]: https://blog.csdn.net/z69183787/article/details/107026232