:
* toMap 如果集合对象有重复的key,会报错Duplicate key....collect(Collectors.toMap(Apple::getId, a -> a,(k1, k2) -> k1));
List 转 ListString,Object>>
List...String,Object>> personToMap = peopleList.stream().map((p) -> {
MapString, Object> map = new...) -> {
MapString, Object> map = new HashMap();
map.put("name", p.name);
map.put("age",..., ListString>> 转 MapString,User>
MapString,ListString>> map = new HashMap();
map.put("java", Arrays.asList