List＜Object＞取出Object中某个属性转成对应的List＜String＞,List＜int＞,和拼接成字符串

	QueryWrapper<CpUser> usersWrapper  = new QueryWrapper<CpUser>();
	    	usersWrapper.select("id")
	    				.in("user_type_id", 1011)
	    				.in("class_id",  Arrays.asList("1,2".split(",")));

方法1：

List<Map<String, Object>> listMaps = cpUserService.listMaps(usersWrapper);

List<Integer>  list =  listMaps.stream().map(m -> Integer.parseInt(m.get("id").toString())).collect(Collectors.toList());

方法2：

List<CpUser> list = cpUserService.list(usersWrapper);
List<Integer>  list list.stream().map(CpUser::getId).collect(Collectors.toList());