map三種指派及map的get方法使用

map String—>String
 map String–>Object
 map String–>List<對象>
 1、
 Map<Long, User> userMap = userRes.getData().stream().collect(Collectors.toMap(User::getId, i -> i));
 List userChannelList = userChannelRemoteService.listAll().getData();2、
 Map<String, String> userChannelMap = userChannelList.stream()
 .collect(Collectors.toMap(UserChannel::getChannelCode, UserChannel::getChannelName));3、
 if (CollectionUtil.isNotEmpty(sysDataDictList)) {
 Map<String, List< SysDataDict>> map = sysDataDictList.stream()
 .collect(Collectors.groupingBy(SysDataDict::getDictGroup));
 map.forEach((key, value) -> {
 itemConfigRespList.add(getCollectionItemConfigResp(key, value));
 });
 }      

public static void main(String[] args) {
Map<Integer, Object> map = new HashMap<Integer, Object>();
map.put(1,111);
map.put(2,222);
String s = "1";
Object o = map.get(s);
sout(0)
}