Java 代码优化: 使用 Stream API 扁平化多层嵌套集合

private Collection convertActivityScoreItems(final List<ScoreItemConfigVO<ActivityScoreItemEntity, ActivityScoreTableEntity>> scoreItemConfigs) { return CollectionUtils.emptyIfNull(scoreItemConfigs) .stream() .map(ScoreItemConfigVO::getScoreItemList) .flatMap(Collection::stream) .map(TreeBuilderUtil::postorderErgodic) .flatMap(Collection::stream) .collect(Collectors.toList()); }