CODEWITHSUNDEEP
java
rickygrimes
rickygrimes

Reputation: 2716

Access first array in a JSON string using JSON Parser

How do I access the array products from the below JSON string? I would ideally do this, and it works -

JSONParser parser = new JSONParser();
Object response = parser.parse(json);
JSONObject jsonObject = (JSONObject) response;
JSONObject info = (JSONObject) jsonObject.get("info");
JSONArray data = (JSONArray) jsonObject.get("products");

But the problem is the root element info is not always the same, so I can't hardcode my code. Basically, I don't want to access products by accessing info first. I want to directly access the products array.

How can I do this?

    {
    "info": {
        "products": [
            {
                "test": 11577,
                "number": 2541,
                "product": "deoderant",
                "id": 1,
                "subId": 5,
                "tempId": 3,
                "name": null,
                "lastModified": "2015-05-24",
                "lastUsed": 5,
                "score": 0.93,
                "season": "Seasonal",
                "availability": 0,
                "itemRanking": null,
                "itemQuantity": 5,
                "listOfStores": [
                    7896
                ]
            }

        ],
        "storeId": 10145678
    }
}

Upvotes: 1

Views: 86

Answers (3)

TongChen
TongChen

Reputation: 1430

Use fasterxml lib,you can write code like below:

ObjectMapper mapper = new ObjectMapper();
// json is your json string
String json = "";
JsonNode jsonNode = node.findParent("products").get("products");
System.out.println(jsonNode);

Upvotes: 0

Ankur Singhal
Ankur Singhal

Reputation: 26077

convert to map, LinkedHashMap or HashMap as per your need, then get the entry value.

public class Test {

    public static void main(String[] args) {
        String json = "{\"info\": {\"products\": [{\"test\": 11577,\"number\": 2541,\"product\": \"deoderant\",\"id\": 1,\"subId\": 5,\"tempId\": 3,\"name\": null,\"lastModified\": \"2015-05-24\",\"lastUsed\": 5,\"score\": 0.93,\"season\": \"Seasonal\",\"availability\": 0,\"itemRanking\": null,\"itemQuantity\": 5,\"listOfStores\": [7896]}],\"storeId\": 10145678}}";

        JSONObject jsonObject;
        try {
            jsonObject = new JSONObject(json);
            Map<String, Object> map = getMap(jsonObject);
            for (Map.Entry<String, Object> entry : map.entrySet()) {
                System.out.println(entry.getKey());
                System.out.println(entry.getValue());
            }
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private static Map getMap(JSONObject object) {
        Map<String, Object> map = new LinkedHashMap<String, Object>();

        Object jsonObject = null;
        String key = null;
        Object value = null;

        try {
            Iterator<String> keys = object.keys();
            while (keys.hasNext()) {

                key = null;
                value = null;

                key = keys.next();

                if (null != key && !object.isNull(key)) {
                    value = object.get(key);
                }

                if (value instanceof JSONObject) {
                    map.put(key, getMap((JSONObject) value));
                    continue;
                }

                if (value instanceof JSONArray) {
                    JSONArray array = ((JSONArray) value);
                    List list = new ArrayList();
                    for (int i = 0 ; i < array.length() ; i++) {
                        jsonObject = array.get(i);
                        if (jsonObject instanceof JSONObject) {
                            list.add(getMap((JSONObject) jsonObject));
                        } else {
                            list.add(jsonObject);
                        }
                    }
                    map.put(key, list);
                    continue;
                }

                map.put(key, value);
            }
        } catch (Exception e) {
            System.out.println(e);
        }
        return map;
    }

}

Output

info
{products=[{test=11577, number=2541, product=deoderant, id=1, subId=5, tempId=3, name=null, lastModified=2015-05-24, lastUsed=5, score=0.93, season=Seasonal, availability=0, itemRanking=null, itemQuantity=5, listOfStores=[7896]}], storeId=10145678}

Upvotes: 1

ceekay
ceekay

Reputation: 1

I don't know if this is the best way - but you can always get the keys of your objects with the keys() method. So you will know the name of the top object.

Upvotes: 0

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