Исключение - NullPointer Получение данных с сервера в ListView

Question

Я сохранил некоторые данные в таблице на сервере, и теперь я пытаюсь показать эти данные в ListView, но каждый раз, когда я получаю NULL POINTER EXCEPTION, пожалуйста, проверьте мои ниже код

OrdersAdapter.java:

public class OrdersAdapter extends BaseAdapter { 
TextView tName,tId,tOid ; 
private Activity activity; 
private ArrayList<HashMap<String, String>> data; 
private static LayoutInflater inflater=null; 
String strName,strMemberID ; 

public OrdersAdapter(Activity a, ArrayList<HashMap<String, String>> d) { 
    activity = a; 
    data=d; 
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
} 

public int getCount() { 
    return data.size(); 
} 

public Object getItem(int position) { 
    return position; 
} 

public long getItemId(int position) { 
    return position; 
} 

public View getView(int position, View convertView, ViewGroup parent) { 
    View vi=convertView; 
    if(convertView==null) 
     vi = inflater.inflate(R.layout.listrow_orders, null); 

    tId = (TextView)vi.findViewById(R.id.txtTotalAmount); 
    tName = (TextView)vi.findViewById(R.id.txtItemDetails); 

    HashMap<String, String> item = new HashMap<String, String>(); 
    item = data.get(position); 

    tId.setText(item.get(strName)); 
    tName.setText(item.get(strMemberID)); 


     String url = "http://172.16.0.4/res/order_fetch.php"; 
     Intent intent= activity.getIntent(); 
     String MemberID = intent.getStringExtra("MemberID"); 
     List<NameValuePair> params = new ArrayList<NameValuePair>(); 
     params.add(new BasicNameValuePair("sMemberID", MemberID)); 
     String resultServer = getHttpPost(url,params); 

     strMemberID = ""; 
     strName = ""; 


     JSONObject c; 
     try { 
     c = new JSONObject(resultServer); 
     strMemberID = c.getString("TotalAmount");    
     strName = c.getString("ItemDetails"); 

     if(!strMemberID.equals("")) 
     {     
      tName.setText(strName); 
      tId.setText(strMemberID);    
     } 
     else 
     {    
      tName.setText("-"); 
      tId.setText("-"); 
     } 
     } catch (JSONException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
     } 
     return vi; 

        }  

    public String getHttpPost(String url,List<NameValuePair> params) { 
     StringBuilder str = new StringBuilder(); 
     HttpClient client = new DefaultHttpClient(); 
     HttpPost httpPost = new HttpPost(url); 

    try { 
     httpPost.setEntity(new UrlEncodedFormEntity(params)); 
     HttpResponse response = client.execute(httpPost); 
     StatusLine statusLine = response.getStatusLine(); 
     int statusCode = statusLine.getStatusCode(); 
     if (statusCode == 200) { // Status OK 
      HttpEntity entity = response.getEntity(); 
      InputStream content = entity.getContent(); 
      BufferedReader reader = new BufferedReader(new InputStreamReader(content)); 
      String line; 
      while ((line = reader.readLine()) != null) { 
       str.append(line); 
      } 
     } else { 
      Log.e("Log", "Failed to download result.."); 
     } 
    } catch (ClientProtocolException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    return str.toString(); 
} 
    } 

OrdersActivity.java:

public class OrdersActivity extends Activity 
{ 
    public static final String LOG_TAG = "OrdersActivity"; 
    ArrayList<HashMap<String, String>> d; 
    ListView mLstView1; 
    @Override 

    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_orders); 

     mLstView1 = (ListView) findViewById(R.id.listView1); 
     OrdersAdapter ordersAdapter = new OrdersAdapter(OrdersActivity.this,d);    
     mLstView1.setAdapter(ordersAdapter); 


     // Permission StrictMode 
     if (android.os.Build.VERSION.SDK_INT > 9) { 
      StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); 
      StrictMode.setThreadPolicy(policy); 
     } 
    } 
} 

Logcat Доклад:

 05-22 14:50:29.373: E/AndroidRuntime(780): FATAL EXCEPTION: main 
05-22 14:50:29.373: E/AndroidRuntime(780): java.lang.RuntimeException: Unable to start activity ComponentInfo{OrdersActivity}: java.lang.NullPointerException 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.ActivityThread.access$600(ActivityThread.java:141) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.os.Handler.dispatchMessage(Handler.java:99) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.os.Looper.loop(Looper.java:137) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.ActivityThread.main(ActivityThread.java:5041) 
05-22 14:50:29.373: E/AndroidRuntime(780): at java.lang.reflect.Method.invokeNative(Native Method) 
05-22 14:50:29.373: E/AndroidRuntime(780): at java.lang.reflect.Method.invoke(Method.java:511) 
05-22 14:50:29.373: E/AndroidRuntime(780): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
05-22 14:50:29.373: E/AndroidRuntime(780): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
05-22 14:50:29.373: E/AndroidRuntime(780): at dalvik.system.NativeStart.main(Native Method) 
05-22 14:50:29.373: E/AndroidRuntime(780): Caused by: java.lang.NullPointerException 
05-22 14:50:29.373: E/AndroidRuntime(780): at OrdersAdapter.getCount(OrdersAdapter.java:58) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.widget.ListView.setAdapter(ListView.java:462) 
05-22 14:50:29.373: E/AndroidRuntime(780): at OrdersActivity.onCreate(OrdersActivity.java:30) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.Activity.performCreate(Activity.java:5104) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 
05-22 14:50:29.373: E/AndroidRuntime(780): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) 
05-22 14:50:29.373: E/AndroidRuntime(780): ... 11 more 

Answer 1

в вашем OrdersActivity, вы никогда не инициализируется d (HashMap) вы передаете в качестве параметра Я к Adpater.

public int getCount() { 
    return (data == null) ? 0 : data.size(); 
} 

Answer 2

Ваше исключение происходит здесь.

at OrdersAdapter.getCount(OrdersAdapter.java:58)