Java8 stream处理List中获取某个属性

List<String> mobileList = userList.stream().map(RemindUserOut::getMobile).collect(Collectors.toList());

//拿出所有AppId，并去重

List<String> appIdList = appIdList.stream().map(WechatWebViewDomain::getAppId).collect(Collectors.toList()).stream().distinct().collect(Collectors.toList());

//拿出集合中重复的billNo，【.filter(map->StringUtils.isNotEmpty(map.getBillNo()))】这是过滤掉为空的数据；否则，有空数据会抛异常

List<String> repeatCodeList = resultList.stream().filter(map->StringUtils.isNotEmpty(map.getBillNo())).collect(Collectors.groupingBy(BillUploadIn::getBillNo, Collectors.counting())).entrySet().stream().filter(entry -> entry.getValue() > 1).map(Map.Entry::getKey).collect(Collectors.toList());

//拿出集合中几个属性拼接后的字符串

List<String> strList = myList.stream().map(p -> p.getName() + "-" + p.getMobile()).collect(Collectors.toList());