java - JSON-String in Map<String, List<Object>> konvertieren, wie funktioniert das?

Question

So stringen Sie JSON wie folgt:
{
"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}]
}
Konvertieren in: Map<String, List<Unit>>
Sie können Jackson, FastJson, Jsoblib verwenden,
Bitte geben Sie mir ein paar Ratschläge!

Answer 1

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;
}

Answer 2

哈哈，看来已经来晚了啊...题主已经采纳答案了嘛，不过lamdba的方式还是要强烈安利给题主哈，因为代码简单的很多（用的fastjson哈，不过其他应该也差不多）

思路就是，题主的json字符串其实总得来说就是一个key-value的形式，应该是满足了最终题主想要的Map<String, List<Unit>>的结构了，所以直接一个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...就这么点代码...（s就是你那个json字符串哈）