我正在尝试通过 json 解析有人可以帮助我吗

Question

我执行了 followinf api 请求 https://api-v3.mbta.com/predictions?sort=arrival_time&filter%5Bstop%5D=70028%2C70029 我遇到了以下解析问题。

  Failed to parse JSON
    org.json.JSONException: Value [{"attributes":{"arrival_time":"2018-04-25T13:20:01-04:00","departure_time":"2018-04-25T13:20:01-04:00",
"direction_id":1,"schedule_relationship":null,"status":null,"stop_sequence":140,"track":null}
,"id":"prediction-36315805-70029-140","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":
{"data":{"id":"70029","type":"stop"}},"trip":{"data":{"id":"36315805","type":"trip"}}},"type":"prediction"},{"attributes"
:{"arrival_time":"2018-04-25T13:26:03-04:00","departure_time":"2018-04-25T13:26:03-04:00","direction_id":0,"schedule_relationship":null,
"status":null,"stop_sequence":50,"track":null},"id":"prediction-36315802-70028-50","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70028","type":"stop"}},"trip":{"data":{"id":"36315802","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T13:29:28-04:00","departure_time":"2018-04-25T13:29:28-04:00","direction_id":1,"schedule_relationship":null,"status":null,"stop_sequence":140,"track":null},"id":"prediction-36315806-70029-140","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70029","type":"stop"}},"trip":{"data":{"id":"36315806","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T13:33:00-04:00","departure_time":"2018-04-25T13:33:00-04:00","direction_id":0,"schedule_relationship":null,"status":null,"stop_sequence":50,"track":null},"id":"prediction-36315803-70028-50","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70028","type":"stop"}},"trip":{"data":{"id":"36315803","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T13:36:20-04:00","departure_time":"2018-04-25T13:36:20-04:00","direction_id":1,"schedule_relationship":null,"status":null,"stop_sequence":140,"track":null},"id":"prediction-36315807-70029-140","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70029","type":"stop"}},"trip":{"data":{"id":"36315807","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T13:44:44-04:00","departure_time":"2018-04-25T13:44:44-04:00","direction_id":0,"schedule_relationship":"ADDED","status":null,"stop_sequence":50,"track":null},"id":"prediction-ADDED-1524238424-70028-50","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70028","type":"stop"}},"trip":{"data":{"id":"ADDED-1524238424","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T13:52:00-04:00","departure_time":"2018-04-25T13:52:00-04:00","direction_id":1,"schedule_relationship":null,"status":null,"stop_sequence":140,"track":null},"id":"prediction-36315809-70029-140","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70029","type":"stop"}},"trip":{"data":{"id":"36315809","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T13:52:39-04:00","departure_time":"2018-04-25T13:52:39-04:00","direction_id":0,"schedule_relationship":null,"status":null,"stop_sequence":50,"track":null},"id":"prediction-36315757-70028-50","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70028","type":"stop"}},"trip":{"data":{"id":"36315757","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T14:00:20-04:00","departure_time":"2018-04-25T14:00:20-04:00","direction_id":0,"schedule_relationship":null,"status":null,"stop_sequence":50,"track":null},"id":"prediction-36315758-70028-50","relationships":{"route":{"data":{"id":"Orange","type":"route"}},"stop":{"data":{"id":"70028","type":"stop"}},"trip":{"data":{"id":"36315758","type":"trip"}}},"type":"prediction"},{"attributes":{"arrival_time":"2018-04-25T14:09:34-04:00","departure_time":"2018-04-25T14:09:34-04:00","direction_id":1,"schedule_relationship":null,"status":null,"stop_sequence":140,"track":null},"id":"prediction-36315810-70029-140","relationships":{"route":{"data":{"id":"

我是这样解析代码的

private void parseItems(List<GalleryItem> items, JSONObject jsonBody)
        throws IOException, JSONException {

    JSONObject photosJsonObject = jsonBody.getJSONObject("data");
    JSONArray photoJsonArray = photosJsonObject.getJSONArray("attributes");

    for (int i = 0; i < photoJsonArray.length(); i++) {
        JSONObject photoJsonObject = photoJsonArray.getJSONObject(i);

        GalleryItem item = new GalleryItem();
        item.setId(photoJsonObject.getString("arrival_time"));
        item.setCaption(photoJsonObject.getString("departure_time"));



        item.setUrl(photoJsonObject.getString("departure_time"));
        items.add(item);
    }
}

有人可以告诉我在解析对象时我在哪里犯了错误。

谢谢

Answer 1

好吧，从您发布的 json 中，data 是一个数组，attributes 是一个对象，您正试图以相反的方式解析它们。试试这个：

JSONArray data = jsonBody.getJSONArray("data");
for (int i = 0; i < data.length(); i++) {

    JSONObject singleData = data.getJSONObject(i);
    JSONObject attributes = singleData.getJSONObject("attributes");

    GalleryItem item = new GalleryItem();
    item.setId(attributes.getString("arrival_time"));
    item.setCaption(attributes.getString("departure_time"));



    item.setUrl(attributes.getString("departure_time"));
    items.add(item);
}

Answer 2

由于data 是一个JSONArray，而您的photosJsonObject 应该是JSONArray 而不是包含对象的对象。我觉得休息还可以。