Json无法在ListView中显示

Question

我正在尝试按照教程将json获取到ListView ，此应用仅显示json中的Array 。 当我从该站点使用url源时，该应用程序可以完全运行，但是当我从数据库中使用本地数据json ，数据不会在我的应用程序中输出。

在第99和68行中（您可以在代码中看到我的命令）

这是我的代码

testing.php

<?php
    //Create Database connection
    $db = mysql_connect("localhost","root","root");
    if (!$db) {
        die('Could not connect to db: ' . mysql_error());
    }

    //Select the Database
    mysql_select_db("skripsi",$db);

    //Replace * in the query with the column names.
    $result = mysql_query("select * from maintenance", $db);  

    //Create an array
    $json_response = array( "maintenance" => array());

    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
        $row_array['mid'] = $row['mid'];
        $row_array['pid'] = $row['pid'];
        $row_array['status'] = $row['status'];
        $row_array['head'] = $row['head'];
        $row_array['note'] = $row['note'];

        //push the values in the array
        array_push($json_response["maintenance"],$row_array);
    }
    echo json_encode($json_response);
?>

这是我的JSONParse类

private class JSONParse extends AsyncTask<String, String, JSONObject> {  **//LOGCAT NAVIGATE TO THIS LINE**
    private ProgressDialog pDialog;
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mid = (TextView) getActivity().findViewById(R.id.mid);
        pid = (TextView) getActivity().findViewById(R.id.pid);
        status = (TextView) getActivity().findViewById(R.id.status);
        head = (TextView) getActivity().findViewById(R.id.head);
        note = (TextView) getActivity().findViewById(R.id.note);

        pDialog = new ProgressDialog(getActivity());
        pDialog.setMessage("Getting Data ...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }
    @Override
    protected JSONObject doInBackground(String... args) {

        JSONParser jParser = new JSONParser();

        // Getting JSON from URL
        JSONObject json = jParser.makeHttpRequestWithoutParams(url);
        return json;
    }
    @Override
    protected void onPostExecute(JSONObject json) {
        pDialog.dismiss();
        try {
            // Getting JSON Array from URL
            maintenance = json.getJSONArray(TAG_OS);   **//LOGCAT NAVIGATE TO THIS LINE**
            for(int i = 0; i < maintenance.length(); i++){
                JSONObject c = maintenance.getJSONObject(i);
                // Storing  JSON item in a Variable
                String mid = c.getString(TAG_MID);
                String pid = c.getString(TAG_PID);
                String status = c.getString(TAG_STATUS);
                String head = c.getString(TAG_HEAD);
                String note = c.getString(TAG_NOTE);
                // Adding value HashMap key => value
                HashMap<String, String> map = new HashMap<String, String>();
                map.put(TAG_MID, mid);
                map.put(TAG_PID, pid);
                map.put(TAG_STATUS, status);
                map.put(TAG_HEAD, head);
                map.put(TAG_NOTE, note);
                oslist.add(map);
                list=(ListView) getActivity().findViewById(R.id.list);
                ListAdapter adapter = new SimpleAdapter(getActivity(), oslist,
                        R.layout.list_v,
                        new String[] { TAG_MID,TAG_PID, TAG_STATUS, TAG_HEAD, TAG_NOTE}, new int[] {
                        R.id.mid,R.id.pid, R.id.status,R.id.head, R.id.note});
                list.setAdapter(adapter);
                list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                    @Override
                    public void onItemClick(AdapterView<?> parent, View view,
                                            int position, long id) {
                        Toast.makeText(getActivity(), "You Clicked at " + oslist.get(+position).get("name"), Toast.LENGTH_SHORT).show();
                    }
                });
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

这是我的JSONObject

public JSONObject makeHttpRequestWithoutParams(String url) {
    // Making HTTP request
    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(url);
        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();
        is = httpEntity.getContent();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }
    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }
    // return JSON String
    return jObj;
}

日志猫

09-16 14:46:30.661    3481-3481/com.example.blackcustomzier.skripsi W/EGL_emulation﹕ eglSurfaceAttrib not implemented
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ org.json.JSONException: No value for android
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at org.json.JSONObject.get(JSONObject.java:354)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at org.json.JSONObject.getJSONArray(JSONObject.java:548)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at com.example.blackcustomzier.skripsi.FragmentMaintain$JSONParse.onPostExecute(FragmentMaintain.java:99)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at com.example.blackcustomzier.skripsi.FragmentMaintain$JSONParse.onPostExecute(FragmentMaintain.java:68)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at android.os.AsyncTask.finish(AsyncTask.java:631)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at android.os.AsyncTask.access$600(AsyncTask.java:177)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:99)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at android.os.Looper.loop(Looper.java:137)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5103)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:525)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-16 14:46:30.791    3481-3481/com.example.blackcustomzier.skripsi W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)

希望有人可以帮我谢谢

Answer 1

维护= json.getJSONArray（TAG_OS）;

看起来TAG_OS的值是“ android”，但是在您的json对象中没有名称为“ android”的数组，因此首先使用一些格式将json inf以字符串格式的形式打印出来，并确保json数组的名称为“ android”。

试试这个链接来解析您的json http://jsonformatter.curiousconcept.com/