Java-异步处理CompletableFuture

先看一个栗子
可以通过CompletableFuture.runAsyns()创建一个异步task，也就是说通过
CompletableFuture.runAsyns()创建的task在执行的时候并不会阻塞主线程，这样会很大程度上提高代码的效率。

public class DiagCompletable {
    public static void main(String[] args) throws InterruptedException {
        completable();
    }

    public static void completable() throws InterruptedException {
        /**
         * 1.CompletableFuture.runAsync()可以创建一个异步任务
         * 2.CompletableFuture.allOf(arrs)是一个同步操作，等到arrs中的所有future都执行完成在执行后面的thenApplyAsync()方法
         * 3.CompletableFuture的异步任务不会阻塞主线程(main方法线程)
         */
        List<CompletableFuture<Void>> futures = new ArrayList<>();
        for(int i=0; i<5; i++){
            CompletableFuture<Void> f = CompletableFuture.runAsync(()->{
                log.info("create future ...");
                try {
                    Thread.sleep(1000 * 2);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                log.info("create future completed");
            }).thenApply((x)->{
                log.info("process then apply");
                return null;
            });
            futures.add(f);
        }
        CompletableFuture<Void>[] arrs = new CompletableFuture[futures.size()];
        arrs = futures.toArray(arrs);
        AtomicBoolean isDone = new AtomicBoolean(false);
        CompletableFuture.allOf(arrs).thenApplyAsync(x->{
            try {
                Thread.sleep(1000 * 5);
		isDone.set(true);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            log.info("all future completed");
            return null;
        });
        while (true){
            if(isDone.get()){
                break;
            }
            log.info("is all task completed");
            Thread.sleep(1000 * 2);
        }
    }
}

输出结果：

> Task :DiagCompletable.main()
10:03:29.423 [main] INFO com.troyqu.refactor.DiagCompletable - is all task completed
10:03:29.423 [ForkJoinPool.commonPool-worker-3] INFO com.troyqu.refactor.DiagCompletable - create future ...
10:03:29.423 [ForkJoinPool.commonPool-worker-2] INFO com.troyqu.refactor.DiagCompletable - create future ...
10:03:29.423 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - create future ...
10:03:31.428 [main] INFO com.troyqu.refactor.DiagCompletable - is all task completed
10:03:31.429 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - create future completed
10:03:31.429 [ForkJoinPool.commonPool-worker-2] INFO com.troyqu.refactor.DiagCompletable - create future completed
10:03:31.430 [ForkJoinPool.commonPool-worker-2] INFO com.troyqu.refactor.DiagCompletable - process then apply
10:03:31.430 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - process then apply
10:03:31.430 [ForkJoinPool.commonPool-worker-2] INFO com.troyqu.refactor.DiagCompletable - create future ...
10:03:31.430 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - create future ...
10:03:31.429 [ForkJoinPool.commonPool-worker-3] INFO com.troyqu.refactor.DiagCompletable - create future completed
10:03:31.430 [ForkJoinPool.commonPool-worker-3] INFO com.troyqu.refactor.DiagCompletable - process then apply
10:03:33.429 [main] INFO com.troyqu.refactor.DiagCompletable - is all task completed
10:03:33.431 [ForkJoinPool.commonPool-worker-2] INFO com.troyqu.refactor.DiagCompletable - create future completed
10:03:33.431 [ForkJoinPool.commonPool-worker-2] INFO com.troyqu.refactor.DiagCompletable - process then apply
10:03:33.433 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - create future completed
10:03:33.434 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - process then apply
10:03:35.434 [main] INFO com.troyqu.refactor.DiagCompletable - is all task completed
10:03:37.439 [main] INFO com.troyqu.refactor.DiagCompletable - is all task completed
10:03:38.439 [ForkJoinPool.commonPool-worker-1] INFO com.troyqu.refactor.DiagCompletable - all future completed