問(wèn)題描述

如何將json串如下:{'1':[{'id':6397891,'rate':81,'type':2,'unitId':1,'userId':7133}, {'id':6397882,'rate':72,'type':1,'unitId':1,'userId':7133}],'2':[{'id':6397906,'rate':90,'type':1,'unitId':2,'userId':7133}]}轉(zhuǎn)換為:Map<String, List<Unit>> 類型通過(guò)jackson,fastjson,jsoblib都可以,求指點(diǎn)!

問(wèn)題解答

public static Map<String, Object> jsonToMap(JSONObject json) throws JSONException { Map<String, Object> retMap = new HashMap<String, Object>(); if(json != JSONObject.NULL) {retMap = toMap(json); } return retMap;}public static Map<String, Object> toMap(JSONObject object) throws JSONException { Map<String, Object> map = new HashMap<String, Object>(); Iterator<String> keysItr = object.keys(); while(keysItr.hasNext()) {String key = keysItr.next();Object value = object.get(key);if(value instanceof JSONArray) { value = toList((JSONArray) value);}else if(value instanceof JSONObject) { value = toMap((JSONObject) value);}map.put(key, value); } return map;}public static List<Object> toList(JSONArray array) throws JSONException { List<Object> list = new ArrayList<Object>(); for(int i = 0; i < array.length(); i++) {Object value = array.get(i);if(value instanceof JSONArray) { value = toList((JSONArray) value);}else if(value instanceof JSONObject) { value = toMap((JSONObject) value);}list.add(value); } return list;}回答2：

哈哈，看來(lái)已經(jīng)來(lái)晚了啊...題主已經(jīng)采納答案了嘛，不過(guò)lamdba的方式還是要強(qiáng)烈安利給題主哈，因?yàn)榇a簡(jiǎn)單的很多（用的fastjson哈，不過(guò)其他應(yīng)該也差不多）

思路就是，題主的json字符串其實(shí)總得來(lái)說(shuō)就是一個(gè)key-value的形式，應(yīng)該是滿足了最終題主想要的Map<String, List<Unit>>的結(jié)構(gòu)了，所以直接一個(gè)Collectors.toMap就搞定啦

Map<String, List<Unit>> result = JSONObject.parseObject(s) .entrySet().stream() .collect(Collectors.toMap(Map.Entry::getKey, entry -> JSONObject.parseArray(String.valueOf(entry.getValue()), Unit.class)));

然后...就完了噻...就這么點(diǎn)代碼...（s就是你那個(gè)json字符串哈）