在Java问题中解析JSON

Question

Sorry I'm very new to parse JSON in java.

I've written a loop that picks 5 cards from a deck of 52 cards (see below). After the cards have been picked i want to validate there is still 52 cards.

On the API it confirms how many cards are remaining but i can't seem to find a value which tells me how many cards have been picked.

https://deckofcardsapi.com/api/deck/new/draw/?count=3

- I've began to write the code below to retrieve the data of how many cards are remaining but it doesn't seem to work.

JSONObject obj = new JSONObject("");
String pageName = obj.getJSONObject("Remaining").getString("Value");
System.out.println("remaining + value");

Below is the JSON to be parsed

{"remaining": 49, "deck_id": "nzzp9cwqokp6", "cards": [{"code": "AS", "images": {"png": "https://deckofcardsapi.com/static/img/AS.png", "svg": "https://deckofcardsapi.com/static/img/AS.svg"}, "value": "ACE", "image": "https://deckofcardsapi.com/static/img/AS.png", "suit": "SPADES"}, {"code": "2S", "images": {"png": "https://deckofcardsapi.com/static/img/2S.png", "svg": "https://deckofcardsapi.com/static/img/2S.svg"}, "value": "2", "image": "https://deckofcardsapi.com/static/img/2S.png", "suit": "SPADES"}, {"code": "6H", "images": {"png": "https://deckofcardsapi.com/static/img/6H.png", "svg": "https://deckofcardsapi.com/static/img/6H.svg"}, "value": "6", "image": "https://deckofcardsapi.com/static/img/6H.png", "suit": "HEARTS"}], "success": true}

-

    int counter = 5;
    for(int i = 1; i <= counter; i++) { //5 inclusive otherwise use <
        String uriString = "https://deckofcardsapi.com/api/deck/new/draw/?count="+i;
        System.out.println(i);

Answer 1

Existing:

JSONObject obj = new JSONObject("");
                    String pageName = obj.getJSONObject("Remaining").getString("Value");
                            System.out.println("remaining + value");

According to your json response "value" is part of cards object. To access values you need to access first cards object then you can extract "value" out of it.

To access value it should be like :

public static void getResponse() throws JSONException {
    String response = "{\"remaining\": 49, \"deck_id\": \"nzzp9cwqokp6\", \"cards\": [{\"code\": \"AS\", \"images\": {\"png\": \"https://deckofcardsapi.com/static/img/AS.png\", \"svg\": \"https://deckofcardsapi.com/static/img/AS.svg\"}, \"value\": \"ACE\", \"image\": \"https://deckofcardsapi.com/static/img/AS.png\", \"suit\": \"SPADES\"}, {\"code\": \"2S\", \"images\": {\"png\": \"https://deckofcardsapi.com/static/img/2S.png\", \"svg\": \"https://deckofcardsapi.com/static/img/2S.svg\"}, \"value\": \"2\", \"image\": \"https://deckofcardsapi.com/static/img/2S.png\", \"suit\": \"SPADES\"}, {\"code\": \"6H\", \"images\": {\"png\": \"https://deckofcardsapi.com/static/img/6H.png\", \"svg\": \"https://deckofcardsapi.com/static/img/6H.svg\"}, \"value\": \"6\", \"image\": \"https://deckofcardsapi.com/static/img/6H.png\", \"suit\": \"HEARTS\"}], \"success\": true}";

    JSONObject responseObj = new JSONObject( response);
    JSONArray contracts = (JSONArray) responseObj.get("cards");
    JSONObject cards = (JSONObject)contracts.get(0);
    System.out.println(cards.get("value"));
}

Answer 2

public static void main(String[] args) throws JSONException, IOException {
    HttpClient httpClient = HttpClientBuilder.create().build();
    HttpGet getRequest = new HttpGet("https://deckofcardsapi.com/api/deck/new/draw/?count=5");
    getRequest.addHeader("accept", "application/json");
    HttpResponse response = httpClient.execute(getRequest);

    String result = EntityUtils.toString(response.getEntity());
    JSONObject jsonResult = new JSONObject(result);

    int pickedCardsCount = jsonResult.getJSONArray("cards").length();
    int remainingCardsCount = jsonResult.getInt("remaining");
    int totalCardsCount = pickedCardsCount + remainingCardsCount;

    System.out.println("No of cards picked: " + pickedCardsCount);
    System.out.println("No of cards remaining: " + remainingCardsCount);
    System.out.println("Total Cards: " + totalCardsCount);
 }