将地图转换为地图列表

我有一个要求,我想转换成地图列表地图。

我尝试了以下代码,

List<Map<String, Object>> response = new ArrayList<>();
Set<Long> categories = new HashSet<>();

List<CCP> ccpList = ccpRepository.findByPIdIn(ids);
Map<Integer, List<Integer>> categoriesByProduct = ccpList.stream()
                  .collect(Collectors.groupingBy(ccp -> ccp.getPId(), Collectors.mapping(ccp-> ccp.getCId(), Collectors.toList())));
for(Entry<Integer, List<Integer>> en : categoriesByProduct.entrySet()) {
    Map<String,Object> responseObject = new HashMap<>();
    responseObject.put("pid", en.getKey());
    responseObject.put("categories",en.getValue());
    response.add(responseObject);
}

有什么方法可以用java 8风格修改以下代码:

for(Entry<Integer, List<Integer>> en : categoriesByProduct.entrySet()) {
    Map<String,Object> responseObject = new HashMap<>();
    responseObject.put("pid", en.getKey());
    responseObject.put("categories",en.getValue());
    response.add(responseObject);
}