java 异步查询统计提高效率

        List<String> idList = Lists.newArrayList("111");
        List<CompletableFuture<Integer>> batchFutures = new ArrayList<>();
        for (String id : idList) {
            CompletableFuture<Integer> future = CompletableFuture.supplyAsync(() -> {
                Integer num = 0;//这里模拟查询统计操作
                return num;
            });
            batchFutures.add(future);
        }
 
        CompletableFuture<List<Integer>> all = CompletableFuture.allOf(batchFutures.toArray(new CompletableFuture[0]))
                .thenApply(v -> batchFutures.stream()
                        .map(CompletableFuture::join)
                        .collect(Collectors.toList()));
        List<Integer> integers = null;
        try {
            integers = all.get();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } catch (ExecutionException e) {
            throw new RuntimeException(e);
        }
 
        int num = 0;
        for (Integer integer : integers) {
            if (integer != null) {
                num += integer;
            }
        }