Невозможно отобразить массив JSONObjects в ListView - Android

Question

В настоящее время я создаю приложение, которое должно собирать JSONObjects (или группы) с сервера, а затем печатать их в ListView. Мне удалось разобрать JSONObjects и выполнить итерацию и распечатать все имена групп в LogCat, но когда я пытаюсь заполнить свой ListView, он всегда выходит пустым.

Это мой класс TCPConnection, где я подключиться к серверу:

public class TCPConnection { 

private Controller controller; 

private RunOnThread thread; 
private Receive receive; 
private Socket socket; 
private DataInputStream input; 
private DataOutputStream output; 
private InetAddress address; 
private int connectionPort; 
private String ip; 
private Exception exception; 
private MainActivity main; 

private static String id; 

public TCPConnection(String ip, int connectionPort, MainActivity main) { 
    this.ip = ip; 
    this.connectionPort = connectionPort; 
    this.main = main; 
    thread = new RunOnThread(); 

} 

public void setController(Controller controller) { 
    this.controller = controller; 
} 


public void connect() { 
    thread.start(); 
    thread.execute(new Connect()); 
} 

public void disconnect() { 
    thread.execute(new Disconnect()); 
} 


public void newMessage(final String answer) { 
    main.runOnUiThread(new Runnable() { 
     public void run() { 
      String message = answer; 
      String type; 
      JSONObject jObj = null; 

      try { 
       jObj = new JSONObject(message); 
       type = jObj.getString("type"); 

       if(type.equals("register")){ 
        recieveID(jObj); 

       } else if(type.equals("groups")){ 
        getAllGroups(jObj); 

       }else{ 
        Log.i("TCPConnection", "Type does not exist"); 
       } 

      } catch (JSONException e) { 
       e.printStackTrace(); 
      } 
     } 
    }); 
} 


//SENDING JOBJ to CONTROLLER 
public void getAllGroups(JSONObject jObj){ 
    Log.i("GRUPPER", "Jobj sent to controller"); 
    controller.setAllGroups(jObj); 
} 


private class Receive extends Thread { 
    public void run() { 
     String result; 
     try { 
      while (receive != null) { 
       result = input.readUTF(); 
       newMessage(result); 
      } 

     } catch (Exception e) { // IOException, ClassNotFoundException 
      receive = null; 
     } 
    } 
} 


private class Connect implements Runnable { 
    public void run() { 
     try { 
      Log.d("TCPConnection","Connect-run"); 
      address = InetAddress.getByName(ip); 
      Log.d("TCPConnection-Connect","Skapar socket"); 
      socket = new Socket(address, connectionPort); 
      Log.d("TCP-CONNECT", "SOCKET INITIALIZED"); 
      input = new DataInputStream(socket.getInputStream()); 
      Log.d("TCP-CONNECT", "INPUTSTREAM INITIALIZED"); 
      output = new DataOutputStream(socket.getOutputStream()); 
      output.flush(); 
      Log.d("TCPConnection-Connect","Strömmar klara"); 
      receive = new Receive(); 
      receive.start(); 
     } catch (Exception e) { // SocketException, UnknownHostException 
      Log.d("TCPConnection-Connect",e.toString()); 
      exception = e; 
     } 
    } 
} 

public class Disconnect implements Runnable { 
    public void run() { 
     try { 
      if (socket != null) 
       socket.close(); 
      if (input != null) 
       input.close(); 
      if (output != null) 
       output.close(); 
      thread.stop(); 
      socket.close(); 
     } catch(IOException e) { 
      exception = e; 
     } 
    } 
} 


public void send(String JSONQuery) { 
    thread.execute(new Send(JSONQuery)); 
} 


public class Send implements Runnable { 
    final String JSONQuery; 

    public Send(String JSONQuery) { 
     this.JSONQuery = JSONQuery; 
    } 

    public void run() { 
     try { 
      output.writeUTF(JSONQuery); 
      output.flush(); 

     } catch (IOException e) { 
      exception = e; 
      newMessage("EXCEPTION"); 
     } 
    } 
} 

Тогда у меня есть мой контроллер:

public class Controller { 

private MainActivity activity; 
private CommunityFragment communityFragment; 
private TCPConnection connection; 
private boolean connected = false; 

ArrayList<String> groupList = new ArrayList<String>(); 

public Controller() { 
} 

public Controller(MainActivity activity, CommunityFragment communityFragment, TCPConnection connection) { 
    this.activity = activity; 
    this.communityFragment = communityFragment; 
    communityFragment.setController(this); 
    this.connection = connection; 
    connection.setController(this); 
    connect(); 
} 


public void allGroups() { 
    StringWriter stringWriter = new StringWriter(); 
    JsonWriter jsonWriter = new JsonWriter(stringWriter); 
    Log.i("MyConnectService", "setAllGroups() kördes"); 
    try { 
     jsonWriter.beginObject().name("type").value("groups").endObject(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
     Log.e("MyConnectService", "setAllGroups fail"); 
    } 
    connection.send(stringWriter.toString()); 
} 

public void setAllGroups(JSONObject jObj) { 

Log.i("GRUPPER", "groupList iteration start"); 
    groupList.add("TEST"); 

    try { 
     JSONArray jsonArr = jObj.getJSONArray("groups"); 

     for (int i = 0; i < jsonArr.length(); i++) { 
      Log.d("GRUPPER", "RECIEVED IN LOOP: " + jsonArr.getJSONObject(i).getString("group")); 
      groupList.add(jsonArr.getJSONObject(i).getString("group").toString()); 
     } 
    } catch (Exception e) { 
     Log.i("GRUPPER", "error in getMembers() for " + e); 
    } 
    Log.i("GRUPPER", "groupList iteration - Done!"); 
} 

public ArrayList<String> getGroupList(){ 
    Log.i("GRUPPER", "groupList collected by communityFrag"); 
    return groupList; 
} 

} 

И это мой CommunityFragment, которые содержат ListView, а также это где вы создание групп

public class CommunityFragment extends Fragment { 

private Controller controller = new Controller(); 

private EditText etGroup; 
private EditText etMember; 
private Button btnSave; 
private ListView lvGroups; 

private String groupName, userName; 
private ArrayAdapter<String> mArrayAdapter; 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    View rootView = inflater.inflate(R.layout.fragment_community, container, false); 

    initializeComponents(rootView); 
    // controller.allGroups(); 
    initializeAdapter(); 

    return rootView; 
} 


public void setController(Controller controller) { 
    this.controller = controller; 
} 


private void initializeComponents(View rootView) { 
    . 
    . 
    . 
     } 
    }); 
} 


public void initializeAdapter() { 
    ArrayList<String> groupList = controller.getGroupList(); 
    //Adapter definierad och sätts till list fragmentet 

    mArrayAdapter = new GroupAdapter(getActivity(), R.id.lv_groups, groupList); 
    lvGroups.setAdapter(mArrayAdapter); 
    Log.i("GRUPPER", "Adapter created"); 
} 

} 

Адаптер группы:

public class GroupAdapter extends ArrayAdapter<String> { 

private ArrayList<String> ArrayListGroups; 
private int Resource; 
private Context context; 
private LayoutInflater vi; 

public GroupAdapter(Context context, int resource, ArrayList<String> objects) { 
    super(context, resource, objects); 

    ArrayListGroups = objects; 
    Resource = resource; 
    this.context = context; 

    vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 

    ViewHolder holder; 
    if(convertView==null){ 
     convertView = vi.inflate(Resource, null); 
     //recycling views using viewholder (items getting offscreen) 
     holder = new ViewHolder(); 

     holder.groupName = (TextView) convertView.findViewById(R.id.tv_list_title); 

     convertView.setTag(holder); 
    }else{ 
     holder = (ViewHolder)convertView.getTag(); 
    } 
    //setting text in each item based on the position in the list 
    holder.groupName.setText(ArrayListGroups.get(position)); 
    return convertView; 
} 

static class ViewHolder{ 
    public TextView groupName; 
} 
public void updateList(){ 
    notifyDataSetChanged(); 
} 
} 

Вот LogCat:

10-29 13:34:32.962 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ onVisibilityChanged() is called, visibility : 4 
10-29 13:34:32.962 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:33.002 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ onVisibilityChanged() is called, visibility : 0 
10-29 13:34:33.002 31680-31699/se.mah.sofand.mapapplication D/TCP-CONNECT﹕ SOCKET INITIALIZED 
10-29 13:34:33.002 31680-31699/se.mah.sofand.mapapplication D/TCP-CONNECT﹕ INPUTSTREAM INITIALIZED 
10-29 13:34:33.002 31680-31699/se.mah.sofand.mapapplication D/TCPConnection-Connect﹕ Strömmar klara 
10-29 13:34:33.002 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:33.122 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:33.142 31680-31680/se.mah.sofand.mapapplication I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: () 
    OpenGL ES Shader Compiler Version: E031.24.00.08+13 
    Build Date: 03/20/14 Thu 
    Local Branch: 0320_AU200_patches 
    Remote Branch: 
    Local Patches: 
     Reconstruct Branch: 
10-29 13:34:33.182 31680-31680/se.mah.sofand.mapapplication D/OpenGLRenderer﹕ Enabling debug mode 0 
10-29 13:34:33.202 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:144 height:144 bitmap id is 199 
10-29 13:34:33.202 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:144 height:144 bitmap id is 200 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ onVisibilityChanged() is called, visibility : 4 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
**10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication I/GRUPPER﹕ Jobj sent to controller 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication I/GRUPPER﹕ groupList iteration start 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication D/GRUPPER﹕ RECIEVED IN LOOP: blajje 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication I/GRUPPER﹕ groupList iteration - Done!** 
10-29 13:34:33.212 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:96 height:96 bitmap id is 201 
10-29 13:34:33.312 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:33.322 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:35.162 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ onVisibilityChanged() is called, visibility : 0 
10-29 13:34:35.162 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:35.992 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:36.022 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 203 
10-29 13:34:36.022 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 204 
10-29 13:34:36.022 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 205 
10-29 13:34:36.032 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 206 
10-29 13:34:36.032 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 207 
10-29 13:34:36.032 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 208 
10-29 13:34:36.032 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 209 
10-29 13:34:36.042 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 210 
10-29 13:34:36.042 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 211 
10-29 13:34:36.042 31680-31680/se.mah.sofand.mapapplication D/skia﹕ GFXPNG PNG bitmap created width:78 height:96 bitmap id is 212 
10-29 13:34:36.062 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ Get MotionRecognitionManager 
**10-29 13:34:36.062 31680-31680/se.mah.sofand.mapapplication I/GRUPPER﹕ groupList collected by communityFrag 
10-29 13:34:36.062 31680-31680/se.mah.sofand.mapapplication I/GRUPPER﹕ Adapter created** 
10-29 13:34:36.062 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:36.082 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 
10-29 13:34:36.382 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ onVisibilityChanged() is called, visibility : 4 
10-29 13:34:36.382 31680-31680/se.mah.sofand.mapapplication D/AbsListView﹕ unregisterIRListener() is called 

Примечания есть только одна группы, созданная именно поэтому только 'blajje' виден.

Как вы видите, список определен до создания адаптера, но я не могу его отобразить. Нет Nullpointer или другого исключения. Любые идеи почему?

Answer 1

Контроллер используется здесь

public void initializeAdapter() { 
    ArrayList<String> groupList = controller.getGroupList(); 

не настроен на использование каких-либо данных. Он инициализируется (= new Controller()), но после этого вы ничего не делаете с ним. У него нет данных для работы. Я думаю, что вы должны сделать это здесь, с помощью метода вы уже создали в классе контроллера

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    View rootView = inflater.inflate(R.layout.fragment_community, container, false); 

    initializeComponents(rootView); 
    // controller.allGroups(); 

    controller.setAllGroups(); // this line should set the data 
    initializeAdapter(); 

    return rootView; 
} 

Если экземпляр контроллера не имеет набора данных, нет никаких данных, передается в адаптере списка, следовательно, не отображаются никаких данных.

Редактировать

экземпляр

Контроллер используется инициализируется как это

private Controller controller = new Controller(); 

Однако класс Контроллер имеет 2 конструктору

public Controller() { 
} 

public Controller(MainActivity activity, CommunityFragment communityFragment, TCPConnection connection) { 
    this.activity = activity; 
    this.communityFragment = communityFragment; 
    communityFragment.setController(this); 
    this.connection = connection; 
    connection.setController(this); 
    connect(); 
} 

Похоже, вы используете неправильный конструктор, потому что пустой, который вы используете в данный момент, не инициализирует экземпляр TCPConnection connection.

Если вы инициализируете экземпляр вашего контроллера с помощью конструктора справа, этот пустой указатель исчезнет.

Answer 2

I have checked the code, find that in this part: 
public class CommunityFragment extends Fragment { 

private Controller controller = new Controller(); 

} 


When you init Controller, you should use this constructor 

public Controller(MainActivity activity, CommunityFragment communityFragment, TCPConnection connection) 
{ 
    this.activity = activity; 
    this.communityFragment = communityFragment; 
    communityFragment.setController(this); 
    this.connection = connection; 
    connection.setController(this); 
    connect(); 
} 

You can try this.