org.json.JSONException：0 没有值

Question

我收到了来自 API 的响应。 但是一旦我到达返回命令，我就会收到以下错误：

W/System.err: org.json.JSONException: No value for 0
W/System.err:     at org.json.JSONObject.get(JSONObject.java:389)
W/System.err:     at org.json.JSONObject.getInt(JSONObject.java:478)
W/System.err:     at bobbydejong.expandabletest.OrderOverzicht.prepareOrderList(OrderOverzicht.java:65)
W/System.err:     at bobbydejong.expandabletest.OrderOverzicht$1.onSuccess(OrderOverzicht.java:37)
W/System.err:     at bobbydejong.expandabletest.GetOrderSwagger.onPostExecute(GetOrderSwagger.java:113)
W/System.err:     at bobbydejong.expandabletest.GetOrderSwagger.onPostExecute(GetOrderSwagger.java:21)
W/System.err:     at android.os.AsyncTask.finish(AsyncTask.java:660)
W/System.err:     at android.os.AsyncTask.-wrap1(AsyncTask.java)

它发生在这段代码上：

public class GetItemsSwagger extends AsyncTask<String, Void, String> {

ArrayList<HashMap<String, Object>> list = new ArrayList<>();
String result2;
private OnEventListener<String> mCallBack;
public Exception mException;
private Context context;
HttpURLConnection conn = null;
OutputStream os = null;
InputStream is = null;
String toastMsg = "Failed to get API response.";
String apiKey;




public GetItemsSwagger(Context context, OnEventListener callback) {
    this.context = context;
    this.mCallBack = callback;
}

@Override
protected String doInBackground(String... strings) {



    try {
        apiKey = strings[1];

        URL url = new URL(strings[0]);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

        conn.setInstanceFollowRedirects(false);
        conn.setRequestMethod("GET");
        conn.setUseCaches(false);
        conn.setRequestProperty("apikey", apiKey);

        int status = conn.getResponseCode();

        if(status >= 400)
            is = conn.getErrorStream();
        else
            is = conn.getInputStream();


        if (conn.getResponseCode() != 200) {
            throw new RuntimeException("Failed : HTTP error code : "
                    + conn.getResponseCode());
        } else {
            toastMsg = "";
        }
        BufferedReader br = new BufferedReader(new InputStreamReader(
                (is)));

        String output;
        while ((output = br.readLine()) != null) {
            toastMsg += output;
        }

        conn.disconnect();



        result2= "";
        return toastMsg;

编辑：

[{"orderGroupID":"1","name":"Patat","orderStatusID":"8","orderTo":"2017-02-24 11:15:00","created":"2017-02-24 10:04:21"},{"orderGroupID":"2","name":"Patat","orderStatusID":"8","orderTo":"2017-03-03 11:00:00","created":"2017-03-03 10:06:53"},{"orderGroupID":"3","name":"Patat","orderStatusID":"8","orderTo":"2017-03-10 11:10:00","created":"2017-03-10 10:27:32"},{"orderGroupID":"4","name":"Patat","orderStatusID":"8","orderTo":"2017-03-17 11:00:00","created":"2017-03-17 08:27:48"},{"orderGroupID":"5","name":"Patat","orderStatusID":"8","orderTo":"2017-03-24 11:00:00","created":"2017-03-24 08:58:08"},{"orderGroupID":"6","name":"Patat","orderStatusID":"8","orderTo":"2017-03-31 11:00:00","created":"2017-03-31 09:26:01"},{"orderGroupID":"7","name":"Patat","orderStatusID":"8","orderTo":"2017-04-07 11:00:00","created":"2017-04-07 10:02:52"},{"orderGroupID":"8","name":"Patat","orderStatusID":"8","orderTo":"2017-04-14 11:00:00","created":"2017-04-14 09:40:43"},{"orderGroupID":"9","name":"Patat","orderStatusID":"8","orderTo":"2017-04-21 11:00:00","created":"2017-04-21 10:01:31"},{"orderGroupID":"11","name":"Patat","orderStatusID":"8","orderTo":"2017-04-28 11:00:00","created":"2017-04-28 10:12:45"},{"orderGroupID":"12","name":"Patat","orderStatusID":"8","orderTo":"2017-05-05 11:00:00","created":"2017-05-05 09:39:56"},{"orderGroupID":"13","name":"Patat","orderStatusID":"8","orderTo":"2017-05-12 11:10:00","created":"2017-05-12 09:52:26"},{"orderGroupID":"14","name":"Patat","orderStatusID":"8","orderTo":"2017-05-19 11:00:00","created":"2017-05-19 09:58:37"}]

这是 JSON 响应

 try {
        JSONArray jObjArray = new JSONArray(orderResult);
        int length = jObjArray.length();
        final ArrayList<String> orderList = new ArrayList<String>();

        for (int i = 0; i < length; i++) {

            HashMap<String, Object> map = new HashMap<>();
            JSONObject jObj = jObjArray.getJSONObject(i);
            map.put("orderGroupID", jObj.getInt("orderGroupID"));
            map.put("0", jObj.getInt("0"));
            map.put("name", jObj.getString("name"));
            map.put("orderStatusID", jObj.getInt("orderStatusID"));
            map.put("2", jObj.getInt("2"));
            map.put("orderTo", jObj.getString("orderTo"));
            map.put("3", jObj.getString("3"));
            map.put("created", jObj.getString("created"));


            String orderTo = jObj.getString("orderTo");
            String orderGroupID = jObj.getString("orderGroupID");


            orderList.add(orderTo+"   "+orderGroupID);

这是我操作代码的地方（不同的类）

我期待您的回复，我一直在尝试在其他帖子上找到这个问题，但似乎这些解决方案对我不起作用，而且问题也不完全相同。如果我错了，请纠正我，但我是初学者！

Answer 1

首先，您的 JSON 响应中的“orderGroupID”值是一个 String，您正尝试通过 jObj.getInt("orderGroupID")); 访问它。你应该使用jObj.getString("orderGroupID"));访问它

其次，你的 JSON 响应中没有任何值为“0”的 Key，所以解析会抛出异常。

Answer 2

由于您的orderGroupID 值为string，因此只需使用jObj.getString("orderGroupID") 而不是jObj.getInt("orderGroupID")。

试试这个：

try {
    JSONArray jObjArray = new JSONArray(orderResult);
    int length = jObjArray.length();
    final ArrayList<String> orderList = new ArrayList<String>();

    for (int i = 0; i < length; i++) {

        HashMap<String, Object> map = new HashMap<>();
        JSONObject jObj = jObjArray.getJSONObject(i);
        map.put("orderGroupID", jObj.getString("orderGroupID"));
        map.put("name", jObj.getString("name"));
        map.put("orderStatusID", jObj.getString("orderStatusID"));
        map.put("orderTo", jObj.getString("orderTo"));
        map.put("created", jObj.getString("created"));

        ..........
        .................
}