Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int org.json.JSONArray.length()' on a null object reference

Question

I need to parse json from String builder, but I get this error:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int org.json.JSONArray.length()' on a null object reference

I don't know why stringBuilder.toString() give me the array with objects!

Here is my code:

try {
    // HttpResponse is an interface just like HttpPost.
    //Therefore we can't initialize them
    HttpResponse httpResponse = httpClient.execute(httpPost);

    // According to the JAVA API, InputStream constructor do nothing.
    //So we can't initialize InputStream although it is not an interface
    InputStream inputStream = httpResponse.getEntity().getContent();

    InputStreamReader inputStreamReader = new InputStreamReader(inputStream);

    BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

    StringBuilder stringBuilder = new StringBuilder();

    String bufferedStrChunk = null;

    while((bufferedStrChunk = bufferedReader.readLine()) != null){
        stringBuilder.append(bufferedStrChunk);
    }

    // return stringBuilder.toString();
    System.out.println("EHEH"+stringBuilder.toString());


    JSONArray mainObject = null;
    try {
        mainObject = new JSONArray(stringBuilder.toString());
    } catch (JSONException e) {
        e.printStackTrace();
    }

    for (int i = 0; i < mainObject.length(); i++) {
        JSONObject object = null;
        try {
            object = mainObject.getJSONObject(i);
        } catch (JSONException e) {
            e.printStackTrace();
        }
        try {
            Video video=new Video();
            String url = object.getString("url");

            String titolo = object.getString("titolo");
            String sottotitolo = object.getString("sottotitolo");
            String data = object.getString("date");
            //video.setId(idd4);
            System.out.println("CAZZO:"+video.getId());
            video.setPic(url);
            video.setTitolo(titolo);
            video.setSottotitolo(sottotitolo);
            video.setData(data);

            videoList.add(video);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

Can someone help me?

JSON RESPONSE:

enter image description here

please add your json response with your question. – Ratilal Chopda Dec 22 '17 at 09:34 — Ratilal Chopda, Dec 22 '17 at 09:34
@Guruji i updated my question with json response – oliver Dec 22 '17 at 09:41 — oliver, Dec 22 '17 at 09:41
@oliver this is not a valid json response. – Ratilal Chopda Dec 22 '17 at 09:43 — Ratilal Chopda, Dec 22 '17 at 09:43
@oliver check my ans is not valid json response. – Ratilal Chopda Dec 22 '17 at 09:49 — Ratilal Chopda, Dec 22 '17 at 09:49

score 1 · Answer 1 · edited Dec 22 '17 at 09:44

1

What does stringBuilder.toString() return? Use System.out.println()

edited Dec 22 '17 at 09:44

Ratilal Chopda

4,162
4
18
31

answered Dec 22 '17 at 09:34

Tidder Jail

472
7
11

this: EHEH{"error":false,"message":"VIDEOs fetched successfully.","pdfs":[{"url":"http:\/\/www.video.mediaset.it\/bin\/199.$plit\/640x360_C_2_video_731367_videoThumbnail.jpg","titolo":"\u201c\u00c8 stata un\u2019esperienza bellissima\u201d","sottotitolo":"Dietr – oliver Dec 22 '17 at 09:35
This will not work, put it in a json validador, it's missing a lot of things – Tidder Jail Dec 22 '17 at 09:39
i cut response because it is so long – oliver Dec 22 '17 at 09:43

score 0 · Answer 2 · edited Dec 22 '17 at 09:45

0

You forgot to Initialize StringBuilder.

First Initialize and then use

StringBuilder sb = new StringBuilder();

edited Dec 22 '17 at 09:45

Ratilal Chopda

4,162
4
18
31

answered Dec 22 '17 at 09:34

Tejas Pandya

3,987
1
26
51

Ratilal Chopda · Accepted Answer · 2017-12-22T10:09:50.297

-1

your mistake is String data = object.getString("data");

JSONObject mainObject = null;
    try 
    {
        mainObject = new JSONObject(stringBuilder.toString());
        JSONArray jsonArrayPDF = mainObject.getJSONArray("pdfs");

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

        JSONObject object = jsonArrayPDF.getJSONObject(i);
        Video video=new Video();
        String url = object.getString("url");

        String titolo = object.getString("titolo");
        String sottotitolo = object.getString("sottotitolo");
        String data = object.getString("data");
        //video.setId(idd4);
        System.out.println("CAZZO:"+video.getId());
        video.setPic(url);
        video.setTitolo(titolo);
        video.setSottotitolo(sottotitolo);
        video.setData(data);

        videoList.add(video);

    }

    } 
    catch (JSONException e) 
   {
        e.printStackTrace();
    }

edited Dec 22 '17 at 10:09

answered Dec 22 '17 at 09:48

Ratilal Chopda

4,162
4
18
31

1

this does not provide answer to the quetion – AskNilesh Dec 22 '17 at 09:50
i update question with screenshot of my complete json! – oliver Dec 22 '17 at 09:55
@oliver please check my ans. – Ratilal Chopda Dec 22 '17 at 10:04
@oliver one of your mistake is String data = object.getString("date"); use this is your response. **data** – Ratilal Chopda Dec 22 '17 at 10:12
THANKS!! you saved me! – oliver Dec 22 '17 at 10:17
@oliver Happy to Help you. – Ratilal Chopda Dec 22 '17 at 10:17

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int org.json.JSONArray.length()' on a null object reference

3 Answers3