Java 代码优化: 使用 Collectors.groupingBy 简化数据分组操作

<p>private Collection&lt;List&lt;List<Object>&gt;&gt; getSheetDatas(final String activityId) {\n    final List<MidLevelDemocracyEvaluationVO> midLevelDemocracyEvaluations = getMidLevelDemocracyEvaluations(activityId);\n    final Map&lt;Integer, List&lt;List<Object>&gt;&gt; collect = CollectionUtils.emptyIfNull(midLevelDemocracyEvaluations)\n        .stream()\n        .collect(Collectors.groupingBy(\n            MidLevelDemocracyEvaluationVO::getOrgSort,\n            Collectors.mapping(this::createDataObjects, Collectors.toList())));\n    return collect.entrySet().stream()\n        .sorted(Map.Entry.comparingByKey())\n        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue,\n            (oldValue, newValue) -&gt; oldValue, LinkedHashMap::new)).values();\n}</p>