java8中的Collectors.groupingBy用法
java8二次收集备忘:
Map<Integer,String> mapAnchor = anchors.stream().collect(Collectors.groupingBy(LiveAnchorInfo::getRoomId, Collectors.mapping(LiveAnchorInfo::getName, Collectors.joining(","))));
原文:
https://blog.csdn.net/u014231523/article/details/102535902