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json串轉(zhuǎn)Map<String, List<Object>>,請問如何操作?

Java

www說 2019-03-01 10:51:00

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jackson,fastjson,jsoblib都可以,求指點(diǎn)!

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3 回答

蕪湖不蕪

TA貢獻(xiàn)1796條經(jīng)驗(yàn) 獲得超7個(gè)贊

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;
}

反對回復(fù) 2019-03-01

冉冉說

TA貢獻(xiàn)1877條經(jīng)驗(yàn) 獲得超1個(gè)贊

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

思路就是，題主的json字符串其實(shí)總得來說就是一個(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）

反對回復(fù) 2019-03-01