java 多线程链式执行 将多线程执行放在流中执行将执行的返回结果,再转换成流然后映射获取结果

 public static List<String> getPriceByComputerFuture(List<NetMall> list,String productName){
        List<String> collect = list.stream().map(mall -> CompletableFuture.supplyAsync(
                () -> String.format(productName + " %s price is %.2f", mall.getNetMallName(), mall.getPriceByName(productName))
        )).collect(Collectors.toList()).stream().map(CompletableFuture::join).collect(Collectors.toList());
        list.stream().map(NetMall::getNetMallName).collect(Collectors.toList());
        return collect;
    }