![Java8 中使用 Stream 对 List 根据字段分组](https://img.wangcx.cn/LightPicture/2022/09/c731c93c3b2ab9e5.jpg?key=717969)
2年前
//根据scoreYear字段进行分组
Map<String, List<Score>> map = scoreList.stream().collect(Collectors.groupingBy(score -> score.getScoreYear()));
//根据scoreYear和studentId字段进行分组
Map<String, List<Score>> map = scoreList.stream().collect(Collectors.groupingBy(score -> score.getScoreYear()+'-'+score.getStudentId()));
«Vita sene libertate nihil» — «Жизнь без свободы — ничто».