什么是org.json.JSONException的Andr​​oid中的含义是什么？ [英] What is The meaning of org.json.JSONException in Android?

问题描述

我发展JSON对象的返回数据到ListView的应用程序。

I am developing an Application of JSON object Which Returns data into ListView.

在一个参数需要传递，这是用户的UID。

In That One Parameter Need to be passed which is Uid of User.

我的code为异步是：

My Code for Async is:

class  AsyncCallWebServicereceiveHistory extends AsyncTask<String, String, String>
{
    ProgressDialog progressDialog;

    @Override
    protected void onPreExecute()
    {
        super.onPreExecute();
        progressDialog = new ProgressDialog(ReceiveHistory.this);
        progressDialog.setTitle("Loading");
        progressDialog.setMessage("Please wait");
        progressDialog.setCancelable(false);
        progressDialog.setIndeterminate(true);
        progressDialog.show();
    }

    @Override
    protected String doInBackground(String... aurl)
    {
        Log.v("receiveHistory","Do in BG-1");
        uid=global.get_user_id();
        try
        {
            HttpPost postMethod = new HttpPost("http://demo1.idevtechnolabs.com/RChatAPI/receive_history.php");

            List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
            postParameters.add(new BasicNameValuePair("uemail", uid));
            BufferedReader bufferedReader = null;

            HttpClient client = new DefaultHttpClient();
            HttpResponse response = null;

            response = client.execute(postMethod);
            final int statusCode = response.getStatusLine().getStatusCode();

            Log.v("Album ::","Response:::--->"+response.toString());
            Log.v("Album ::","Status Code:::--->"+statusCode);

            bufferedReader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            StringBuffer stringBuffer = new StringBuffer("");
            String line = "";
            String LineSeparator = System.getProperty("line.separator");
            while ((line = bufferedReader.readLine()) != null)
            {
                stringBuffer.append(line + LineSeparator);
            }
            bufferedReader.close();

            //-------------CONVERT DATA TO JSON---------------------------------

            try
            {
                String myjsonstring = stringBuffer.toString();

                JSONArray jsonArray = new JSONArray(myjsonstring);

                JSONObject jsonObj = null;

                jsonObj = jsonArray.getJSONObject(0);
                code = jsonObj.getString("code");
                receiveMsgData.clear();

                Log.v("Home ::","Code:::--->"+code);

                code="0";
                if(code.equals("0"))
                {
                    for(int i=0; i<jsonArray.length();i++)
                    {

                            jsonObj = jsonArray.getJSONObject(i);
                            uname=jsonObj.getString("name");
                            uage = jsonObj.getString("age");
                            usex = jsonObj.getString("sex");
                            body = jsonObj.getString("country");
                            text= jsonObj.getString("text");

                            HashMap<String, String> tmp_album = new HashMap<String, String>();
                            tmp_album.put("receive_data", "Text");
                            Log.v("receive History","receive Data");
                            receiveMsgData.add(tmp_album);

                    }
                }
                catch (Exception e)
                {
                    Log.v("Home ::","Call JSON Exception in get Album in List--->"+e.toString());
                    e.printStackTrace();
                }
            }
            catch (Exception e)
            {
                Log.v("Exception: Get get Album in List","Name-"+e.toString());
                e.printStackTrace();
            }

            return code;
        }

        @Override
        protected void onPostExecute(String code)
        {
            if(code.equals("0"))
            {
                Receive_History_Custom_Adapter adapter = new Receive_History_Custom_Adapter(getApplicationContext(), receiveMsgData);
                lv.setAdapter(adapter);

            }
            else
            {
                Toast.makeText(getApplicationContext(), "Data not found", Toast.LENGTH_SHORT).show();
            }

            try
            {
                progressDialog.dismiss();
                progressDialog = null;
            }
            catch (Exception e)
            {
                // nothing
            }
        }
    }
}

而且我得到了以下异常：

Call JSON Exception in get Album in List--->org.json.JSONException: Value [] at 0 of type org.json.JSONArray cannot be converted to JSONObject

的json性反应是：

[
    {
        "code":"0", "user_id":"21", "msg_id":"115", "name":"Sagar", "age":"18", "sex":"Male", "country":
        " India", "text":"hi", "photo":"demo.idevtechnolabs.com", "cnt":"1"
    },
    {
        "code":"0", "user_id":"18", "msg_id":"114", "name":"Ramani", "age":"20", "sex":"Male", "country":
        "Pakistan", "text":"hi", "photo":"demo.idevtechnolabs.com", "cnt":"1"
    }
]

谁能告诉我什么是这个原因，我怎么能解决这个问题吧。

Can anyone tell me what is the cause of this and how can I solve this please.

在此先感谢！

推荐答案

我想你想每一个项目从 JSONArray 添加到邮件列表，如果$ C这个项目的$ C等于 0 。如果是这样，你的code是错误的，它更容易重新写它不仅仅是解释：

I think you are trying to add every item from JSONArray to the list of messages if the code of this item equals to 0. If so, your code is wrong and it's easier to re-write it than just explain:

try {
    String myjsonstring = stringBuffer.toString();
    JSONArray jsonArray = new JSONArray(myjsonstring);
    receiveMsgData.clear();
    for (int i = 0; i < jsonArray.length(); i++) {
        if (jsonArray.getJSONObject(i).getInt("code") == 0) {
            JSONObject data = jsonArray.getJSONObject(i);
            HashMap<String, String> tmp_album = new HashMap<String, String>();
            tmp_album.put("name", data.getString("name"));
            tmp_album.put("age", data.getString("age"));
            tmp_album.put("sex", data.getString("sex"));
            tmp_album.put("country", data.getString("country"));
            tmp_album.put("text", data.getString("text"));
            receiveMsgData.add(tmp_album);
        }
    }

} catch (Exception e) {
    Log.v("Home ::", "Call JSON Exception in get Album in List--->" + e.toString());
    e.printStackTrace();
}

在这里，我们遍历 JSONArray ，并检查 code 等于 0 。如果是平等的，我们把必要的字段来临时的HashMap ，然后将其追加到消息列表。

Here we are iterating over the JSONArray and check if code is equal to 0. If it's equal, we put the necessary fields to the temporary HashMap and then append it to the messages list.

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