标签：collectResult stream Collectors TreeMap 集合 moduleList 排序
根据Hash值排序的，无序排序的
List<ModuleVo> moduleList=new ArrayList();
Map<Integer, List<ModuleVo>> collectResult = moduleList.stream().collect(Collectors.groupingBy(ModuleVo::getProjectId));
根据time进行升序排序,如下
TreeMap<Integer, List<ModuleVo>> collectResult = moduleList.stream().collect(Collectors.groupingBy(ModuleVo::getTime,TreeMap::new,Collectors.toList()));
TreeMap默认按照key升序排序
TreeMap<Integer, List<ModuleVo>> collectResult = moduleList.stream().collect(Collectors.groupingBy(ModuleVo::getTime,TreeMap::new,Collectors.toList())).descendingMap();
标签：collectResult,
stream,
Collectors,
TreeMap,
集合,
moduleList,
排序
From： https://www.cnblogs.com/byteexpress/p/18321930