Java代码优化：使用Stream API提升效率

return tableSource.stream() .filter(Objects::nonNull) .map(this::convertScores) .flatMap(l -> l.stream() .flatMap(scoreItem -> TreeBuilderUtil.postorderErgodic(scoreItem).stream())) .map(scoreItem -> createScoreRecode(scoreItem, activityId)) .collect(Collectors.toList());