1.根据属性过滤list
List<AllManagerBean> testLists = broadCastRoomMapper.allManagerlist();
List<AllManagerBean> mans = testLists.stream().filter(j->j.getRoomId().equals(roomid)).collect(Collectors.toList());
//过滤某一属性，成一个新集合
List<String> uids = testLists.stream().map(e->e.getUserid()).collect(Collectors.toList());
2.遍历集合
List<ManagerBean> managerListNew = new ArrayList<ManagerBean>();
if (mans != null ){
mans.forEach(man->{
managerListNew.add(man);
});
}
3.根据某一集合对象中的某一属性，排序
List<Model> thlistbysort = thlist.stream().sorted(Comparator.comparing(Model::getSort)).collect(Collectors.toList()); //正序
List<Model> thlistbysort = thlist.stream().sorted(Comparator.comparing(Model::getSort).reversed()).collect(Collectors.toList()); //倒序
4.对List<String>进行正序，倒序排列
//正序排列
Collections.sort(s);
//倒序排列（先对list正序排列，然后反向排序）
Collections.sort(s); Collections.reverse(s);//反向排序
关于lanbda表达式相关基础可参考