Возвращенный JSONObject всегда null

Я разрабатываю приложение для Android, которое отправляет имя пользователя и пароль в базу данных MySQL и получает ответ («успех» или «ошибка») в активности входа. Но возвращаемый объект JSONObject имеет значение NULL. Ниже приведены кодыВозвращенный JSONObject всегда null

userauth.php

<?php 
    //Connecting to mysql db 
    include("db.php"); 

    //Check for POST request 
    //if(isset($_POST['tag']) && $_POST['tag'] !=''){ 
     //Get tag 
    // $tag = $_POST['tag']; 
    //} 
    //Getting username and password from android via JSON 
    $username = $_POST['username']; 
    $password = $_POST['password']; 


    //Creating respose array 
    $respose = array("tag" => $tag, "success" => 1, "error" =>0); 

    //Getting data from json 
    //$username='asanka102'; 
    //$password='asanka102'; 

    //Querying mysql database against userauth table for user auth 
    $sql = "SELECT * FROM userauth WHERE username='$username' AND password='$password'"; 
    $qry = mysql_query($sql); 
    $fin_result = mysql_num_rows($qry); 

    //Returning true when user exists & return false when user doen's exist 
    //if$fin_result > 0(){ 
    // return true; 
    //}else{ 
    // return false; 
    //} 
    if($fin_result > 0){ 
     //User found, login should be granted 
     $response["success"] = 1; 
     echo json_encode($response); 
    }else{ 
     //User not found, login shold be prohibited 
     $response["error"] = 0; 
     $response["error_msg"] = 'Invalid login'; 
     echo json_encode($response); 
    } 


?>

MainActivity.java

public class MainActivity extends Activity { 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     etUsername = (EditText) findViewById(R.id.et_username); 
     etPass = (EditText) findViewById(R.id.et_password); 

     errorTxt = (TextView) findViewById(R.id.text_invalid_input); 

     loginButton = (Button) findViewById(R.id.button_login); 
     loginButton.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 

       new GetPassword().execute(); 


      } 
     }); 

    } 



    private class GetPassword extends AsyncTask<Void, Void, Void> { 

     @Override 
     protected Void doInBackground(Void... arg0) { 

      String username = etUsername.getText().toString(); 
      String password = etPass.getText().toString(); 
      UserFunctions userFunctions = new UserFunctions(); 
      JSONObject json = userFunctions.loginUser(username, password); 

      //Do other things 



      return null; 
     } 

     @Override 
     protected void onPostExecute(Void result) { 
      // TODO Auto-generated method stub 
        if (pDialog.isShowing()) 
         pDialog.dismiss(); 

     } 

    }

UserFunctions.java

public class UserFunctions { 

    private JSONParser jsonParser; 

    private static String login_url = "http://192.168.100.172/android/userauth.php"; 

    public UserFunctions(){ 
     jsonParser = new JSONParser(); 
    } 

    /** 
    * function make Login Request 
    * @param username 
    * @param password 
    * */ 
    public JSONObject loginUser(String username, String password){ 
     // Building Parameters 
     List<NameValuePair> params = new ArrayList<NameValuePair>(); 
     params.add(new BasicNameValuePair("username", username)); 
     params.add(new BasicNameValuePair("password", password)); 
     JSONObject json = jsonParser.getJSONFromUrl(login_url, params); 
     // return json 
     // Log.e("JSON", json.toString()); 
     return json; 
    } 
}

JSONParser.java

public class JSONParser { 

    static InputStream is = null; 
    static JSONObject jObj = null; 
    static String json = ""; 

    // constructor 
    public JSONParser() { 
     // Empty constructor 
    } 

    // function get json from url 
    // by making HTTP POST or GET mehtod 
    public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) { 

     // Making HTTP request 
     try { 
      // defaultHttpClient 
      DefaultHttpClient httpClient = new DefaultHttpClient(); 
      HttpPost httpPost = new HttpPost(url); 
      httpPost.setEntity(new UrlEncodedFormEntity(params)); 

      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(); 
      Log.e("JSON", json); 
     } 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; 

    } 

}

LogCat придает этому

02-11 12:29:10.457: E/Buffer Error(13927): Error converting result java.lang.NullPointerException: lock == null 
02-11 12:29:10.457: E/JSON Parser(13927): Error parsing data org.json.JSONException: End of input at character 0 of 
02-11 12:29:10.457: W/dalvikvm(13927): threadid=11: thread exiting with uncaught exception (group=0x41ba5ba8) 
02-11 12:29:10.467: D/dalvikvm(13927): GC_FOR_ALLOC freed 280K, 2% free 17142K/17456K, paused 10ms, total 11ms 
02-11 12:29:10.477: E/AndroidRuntime(13927): FATAL EXCEPTION: AsyncTask #1 
02-11 12:29:10.477: E/AndroidRuntime(13927): Process: collector.lbfinance, PID: 13927 
02-11 12:29:10.477: E/AndroidRuntime(13927): java.lang.RuntimeException: An error occured while executing doInBackground() 
02-11 12:29:10.477: E/AndroidRuntime(13927): at android.os.AsyncTask$3.done(AsyncTask.java:300) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.util.concurrent.FutureTask.setException(FutureTask.java:222) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.util.concurrent.FutureTask.run(FutureTask.java:242) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.lang.Thread.run(Thread.java:841) 
02-11 12:29:10.477: E/AndroidRuntime(13927): Caused by: java.lang.NullPointerException 
02-11 12:29:10.477: E/AndroidRuntime(13927): at collector.lbfinance.MainActivity$GetPassword.doInBackground(MainActivity.java:102) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at collector.lbfinance.MainActivity$GetPassword.doInBackground(MainActivity.java:1) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at android.os.AsyncTask$2.call(AsyncTask.java:288) 
02-11 12:29:10.477: E/AndroidRuntime(13927): at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
02-11 12:29:10.477: E/AndroidRuntime(13927): ... 4 more

источник

2014-02-11 Thahzan Mohomed

Я думаю, вам стоит $ response ["error"] = 1 в блоке else –

Хорошо, я его поменяю, но это не почему JSONObject имеет нулевое значение? –

ли $fin_result возвращающие строки?

Попробуйте следующее

try { 
     BufferedReader reader = new BufferedReader(new InputStreamReader(
       is, "utf-8"), 8); 
     StringBuilder sb = new StringBuilder(); 
     String line = null; 
     while ((line = reader.readLine()) != null) { 
      sb.append(line + "\n"); 
     } 
     is.close(); 
     json = sb.toString(); 
     Log.e("JSON", json); 
    } 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;

источник

2014-02-11 06:49:00 Carbongixxer

Спасибо, помощник. Эти швы сделали трюк. Спасибо миллион –

Что делает LogCat сказать вашим is.close(); json = sb.toString(); Log.e("JSON", json);, который находится в JSONParser.java.

источник

2014-02-11 06:54:45 ZhangLei

Добавлены журналы. Проверьте редактирование –

Возвращенный JSONObject всегда null

ответ

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