Question

我正在开发一个Android项目。我正在创建一个图形并用json内容填充图形。

我的问题是我一直收到这个错误，我不知道为什么。 java.lang.NegativeArraySizeException：-2

My Log.v显示数组的内容。所以它不是空的。也许我错过了什么。

我浏览其余的api并将所有内容添加到arraylist resModelList。在onPostExecute中，我想将y轴值添加到此数组列表yVals1中。这是我得到我的错误的地方。（java.lang.NegativeArraySizeException：-2）

如果我添加这样的值，我没有错误。

yVals1 = new ArrayList<Entry>();
    yVals1.add(new Entry(1451606400, 10));
    yVals1.add(new Entry(1454284800, 20));
    yVals1.add(new Entry(1456790400, 30));
    yVals1.add(new Entry(1459468800, 50));

我的代码
全局变量

ArrayList<ResultModel> resModelList;
ArrayList<Entry> yVals1;

解析Json

//getResult
public class JSONTask extends AsyncTask<String, String, List<ResultModel>> {

    @Override
    protected List<ResultModel> doInBackground(String... params) {
        BufferedReader reader = null;
        HttpURLConnection connection = null;
        try {
            URL url = new URL(params[0]);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestProperty("Cookie",session_name+"="+session_id);
            connection.setRequestProperty("X-CSRF-Token", token);
            //connection.setRequestProperty("Accept-Encoding", "identity");
            connection.connect();

            int length = connection.getContentLength();

            InputStream stream = connection.getInputStream();
            reader = new BufferedReader(new InputStreamReader(stream));

            String line = "";
            StringBuffer buffer = new StringBuffer();
            while ((line = reader.readLine()) != null){
                buffer.append(line);
            }

            Log.v("TESt", " " + length);

            String finalJson = buffer.toString();
            JSONArray parentArray = new JSONArray(finalJson);
            resModelList = new ArrayList<>();

            for(int i=0; i<parentArray.length(); i++){
                JSONObject finalObject = parentArray.getJSONObject(i);
                ResultModel resModel = new ResultModel();
                resModel.setPost_date(finalObject.getString("post_date"));
                resModel.setHow_much_has_ocd(finalObject.getString("how_much_has_ocd"));
                resModelList.add(resModel);
            }
            return resModelList;

        }catch (MalformedURLException e){
            e.printStackTrace();
        }catch (IOException e){
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        } finally {
            if(connection != null) {
                connection.disconnect();
            }
            try {
                if(reader != null){
                    reader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    @Override
    protected void onPostExecute(List<ResultModel> result) {
        super.onPostExecute(result);
        if(!resModelList.isEmpty()){
//here is where i get my errors
            yVals1 = new ArrayList<Entry>();
            for (ResultModel ocd : resModelList){
                int score =  Integer.parseInt(ocd.getHow_much_has_ocd());
                int timeStamp =  Integer.parseInt(ocd.getPost_date());
//I get these log values
                Log.v("Score: ", " " + score + " Timestamp: " + timeStamp);
                yVals1.add(new Entry(timeStamp, score));
            }
            graph();
            Log.v("Not Empty list", "");
        }else {
            Log.v("Empty list", "");
        }
    }
}

finalJson log.v

[{"post_date":"1481895820","did_you_avoid":"25","how_much_has_ocd":"81","how_would_you_rate":"82","overall_how_would":"35","were_there_any_distressing":"0","uid":"2"},{"post_date":"1481723564","did_you_avoid":"13","how_much_has_ocd":"10","how_would_you_rate":"13","overall_how_would":"16","were_there_any_distressing":"0","uid":"2"},{"post_date":"1481723488","did_you_avoid":"28","how_much_has_ocd":"56","how_would_you_rate":"75","overall_how_would":"32","were_there_any_distressing":"0","uid":"2"},{"post_date":"1481537274","did_you_avoid":"53","how_much_has_ocd":"59","how_would_you_rate":"15","overall_how_would":"71","were_there_any_distressing":"1","uid":"2"},{"post_date":"1481295470","did_you_avoid":"67","how_much_has_ocd":"64","how_would_you_rate":"66","overall_how_would":"57","were_there_any_distressing":"0","uid":"2"},{"post_date":"1481097609","did_you_avoid":"72","how_much_has_ocd":"85","how_would_you_rate":"62","overall_how_would":"64","were_there_any_distressing":"0","uid":"2"},{"post_date":"1480673252","did_you_avoid":"33","how_much_has_ocd":"69","how_would_you_rate":"84","overall_how_would":"37","were_there_any_distressing":"1","uid":"2"},

我是初学者，所以这可能只是一个简单的错误提前致谢

Answer 1

我发现了错误。这是我的图表库。

我正在使用MPAndroidChart库，您需要对数据进行排序。我的后端被排序了desc。我不得不将其更改为发布日期（asc）。

它与此问题有关。 NegativeArraySizeException adding Scatter Data to a CombinedChart

我希望这有助于其他人。

继续得到java.lang.NegativeArraySizeException：-2，不知道为什么

1 个答案: