尝试使用一个JSONArray解析JSONObject时为空JSON响应

Question

I got code that gets JSONArrays , but however when I try to get JSONObject that contains only one JSONArray it gives me empty JSONArray .

For example if I need to get data from this JSONObject :

{"events":[{"start":1357714800,"end":1357736400,"name":"Example1","description":""}]}

I get {"events":[]} as JSONObject , [] meaning that it doesn't contain any JSONArrays. Also length of JSONObject is in this case 0. But it doesn't throw any kind of Exceptions .

but if JSONObject contains multiple JSONArrays like this:

{"events":[{"start":1357714800,"end":1357736400,"name":"Example1","description":""},{"start":1357714600,"end":1357736500,"name":"Example2","description":""},{"start":1357514800,"end":1357536400,"name":"Example3","description":""}]}

then my code works perfect.

Here is the code I use to parse JSON:

private void getObjects(String url) throws JSONException, Exception {
        JSONObject jsonObject = new JSONObject(new NetTask().execute(url).get());
        JSONArray job1 = jsonObject.getJSONArray("events");
        System.out.println(jsonObject.toString());
        System.out.println("JOB1 LENGTH: "+job1.length());
        for (int i = 0; i < job1.length(); i++) {
            JSONObject jsonEvent = job1.getJSONObject(i);
            int start = jsonEvent.getInt("start");
            int end = jsonEvent.getInt("end");
            String name = jsonEvent.getString("name");
            String description = jsonEvent.getString("description");
        }
    }

    public class NetTask extends AsyncTask<String, Integer, String>
    {
        @Override
        protected String doInBackground(String... params)
        {
            String jsonText = "";
            BufferedReader reader = null;
            try {
                URL url = new URL(params[0]);
                reader = new BufferedReader(new InputStreamReader(url.openStream()));
                StringBuffer buffer = new StringBuffer();
                int read;
                char[] chars = new char[1024];
                while ((read = reader.read(chars)) != -1) {
                    buffer.append(chars, 0, read);
                }

                jsonText = buffer.toString();
            } catch (MalformedURLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                if (reader != null) {
                    try {
                        reader.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            return jsonText;
        }
    }

is there something wrong that I am missing or is this normal behaviour?

Answer 1

I tried your given code (though I just made the AsyncTask just return the single-array string, and had to replace the opptunti.getString() stuff with jsonEvent.getString()). It worked fine, aside from the fact that you're probably blocking the UI thread to wait for the server response.

My guess is the problem is that you are hitting the wrong URL, that the parameters are wrong or something like that.