Arrays JSONArray没有值

JSONArray的问题。这是我的密码，帮帮我 这是我的JsonObject和错误。。 Json错误：{“用户名”：“rafyluc”，“记录”：“500”}{“用户名”：“inkinati”，“记录”：“600”}{“用户名”：“rafyluc”，“记录”：“500”}{“用户名”：“inkinati”，“记录”：“600”}

公共类ListaAlanni扩展了AppCompative活动{
私有静态ArrayList alunni；
AlunniListAdapter自定义适配器；
私有字符串标记=listaaluni.class.getSimpleName（）；
专用静态字符串url=”http://192.168.1.11:80/webservice/lista.php";
ArrayList项目列表；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.lista_alunni）；
getSupportActionBar（）.setTitle（“Lista Alunni”）；
alunni=新阵列列表（10）；
popola（）；
}
私有void setTextLista（）{
ListView ll=（ListView）findViewById（R.id.lista）；
ll.setAdapter（新的AlunniListAdapter（Listaaluni.this，R.layout.lista_row，alunni））；
}
私人空房{
新建异步任务（）{
@凌驾
受保护的void onPreExecute（）{
alunni=新阵列列表（10）；
}
@凌驾
受保护对象doInBackground（对象…参数）{
HttpHandler sh=新的HttpHandler（）；
字符串jsonStr=sh.makeServiceCall（url）；
if（jsonStr！=null）{
试一试{
JSONObject jsonObj=新的JSONObject（jsonStr）；
Log.d（“Debug_对象”，String.valueOf（jsonObj））；
//获取JSON数组节点
//试一试{
//JSONArray jArray=新JSONArray（jsonStr）；
JSONArray jArray=jsonObj.getJSONArray（jsonStr）；
Log.d（“DEBUG_json”，String.valueOf（jArray））；
for（int i=0；i

看看您的代码，似乎是

JSONArray jArray=jsonObj.getJSONArray（jsonStr）；

是导致问题的原因

jsonObj.getJSONArray

要求传递属性的名称，例如

jsonObj.getJSONArray（“数组_属性”）

但是，您似乎是

public class ListaAlunni extends AppCompatActivity {
    private static ArrayList<Alunni> alunni;
    AlunniListAdapter customAdapter;
    private String TAG = ListaAlunni.class.getSimpleName();
    private static String url = "http://192.168.1.11:80/webservice/lista.php";

    ArrayList<HashMap<String, String>> itemList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.lista_alunni);
        getSupportActionBar().setTitle("Lista Alunni");
        alunni = new ArrayList<Alunni>(10);
        popola();
    }

    private void setTextLista() {
        ListView ll = (ListView) findViewById(R.id.lista);
        ll.setAdapter(new AlunniListAdapter(ListaAlunni.this, R.layout.lista_row, alunni));
    }

    private void popola() {
        new AsyncTask<Object, Object, Object>() {

            @Override
            protected void onPreExecute() {
                alunni = new ArrayList<Alunni>(10);
            }

            @Override
            protected Object doInBackground(Object... params) {
                HttpHandler sh = new HttpHandler();
                String jsonStr = sh.makeServiceCall(url);
                if (jsonStr != null) {
try {
                        JSONObject jsonObj = new JSONObject(jsonStr);
                        Log.d("Debug_object", String.valueOf(jsonObj));

                        // Getting JSON Array node
                        // try {
                        //JSONArray jArray=new JSONArray(jsonStr);
                        JSONArray jArray = jsonObj.getJSONArray(jsonStr);
                        Log.d("DEBUG_json", String.valueOf(jArray));
                        for (int i = 0; i < jArray.length(); i++) {
                            JSONObject json_data = jArray.getJSONObject(i);
                            Log.i("TEST", "Username: " + json_data.getString("Username") +
                                    ", record: " + json_data.getString("Record")

                            );
                            String nome= json_data.getString("Username");
                            String record=json_data.getString("Record");
                          //  alunni.add(new Alunni(nome,record));

                            HashMap<String, String> item = new HashMap<>();
                            item.put("Username", nome);
                            item.put("Record", record);

                            // adding item to item list
                            itemList.add(item);
                        }

                    } catch (final JSONException e) {
                        Log.e(TAG, "Json errore: " + e.getMessage());
runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                Toast.makeText(getApplicationContext(),
                                        "Json errore: " + e.getMessage(),
                                        Toast.LENGTH_LONG)
                                        .show();
                            }
                        });

                    }
                } else {
                    Log.e(TAG, "Couldn't get json from server.");
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(getApplicationContext(),
                                    "Couldn't get json from server. Check LogCat for possible errors!",
                                    Toast.LENGTH_LONG)
                                    .show();
                        }
                    });

                }

                return null;
            }

 @Override
            protected void onPostExecute(Object o) {
                setTextLista();

            }
        }.execute();
    }

}


classe HttpHandler:

public class HttpHandler {

    private static final String TAG = HttpHandler.class.getSimpleName();

    public HttpHandler() {
    }

    public String makeServiceCall(String reqUrl) {
        String response = null;
        try {
            URL url = new URL(reqUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("POST");
            // read the response
            InputStream in = new BufferedInputStream(conn.getInputStream());
            response = convertStreamToString(in);
        } catch (MalformedURLException e) {
Log.e(TAG, "MalformedURLException: " + e.getMessage());
        } catch (ProtocolException e) {
            Log.e(TAG, "ProtocolException: " + e.getMessage());
        } catch (IOException e) {
            Log.e(TAG, "IOException: " + e.getMessage());
        } catch (Exception e) {
            Log.e(TAG, "Exception: " + e.getMessage());
        }
        return response;
    }

    private String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line).append('\n');
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
}