如何在java中用CompletableFuture处理列表列表？

CompletableFuture<List<Integer>> futureList = CompletableFuture.supplyAsync(() -> {
    // 生成列表的逻辑
    List<Integer> list = new ArrayList<>();
    // 添加元素到列表
    list.add(1);
    list.add(2);
    list.add(3);
    return list;
});

CompletableFuture<List<Integer>> processedFutureList = futureList.thenApplyAsync(list -> {
    // 对列表中的每个元素进行处理
    List<Integer> processedList = new ArrayList<>();
    for (Integer num : list) {
        processedList.add(num * 2);
    }
    return processedList;
});

List<Integer> resultList = processedFutureList.join();
System.out.println(resultList);