GroupBy
用法地址:https://www.cnblogs.com/henuyuxiang/p/14989223.html
Map<String, Set<String>> sourceTargetsMap = staticEdges.stream()
.collect(Collectors.groupingBy(EdgeModel::getSource, Collectors.mapping(EdgeModel::getTarget, Collectors.toSet())));
用法地址:https://www.cnblogs.com/henuyuxiang/p/14989223.html
Map<String, Set<String>> sourceTargetsMap = staticEdges.stream()
.collect(Collectors.groupingBy(EdgeModel::getSource, Collectors.mapping(EdgeModel::getTarget, Collectors.toSet())));