title: Progressbar on a null object reference in Fragment
body: <p>In my fragment getting error when i place my progress bar in <strong>ListView</strong> in fragment my app was crashed ,progress bars was not displaving when I load my fragment please nay one help me how to resolve this</p>
  
  <p>Fragment.java</p>
  
  <pre><code>ListAdapter adapter;
  public static ArrayList&lt;Pojo&gt; gridData;
   GridView grd;
   private ProgressBar mProgressBar;
  private String Sam_URL = "http://example.com/rest/Main/document?name=kids@_$example";
  
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
          Bundle savedInstanceState) {
      View rootView = inflater.inflate(R.layout.gridlayout_progressbar, container, false);
      System.out.println("Servce Called");
      gridData=new ArrayList&lt;Pojo&gt;();
  
      grd =(GridView)rootView.findViewById(R.id.gridview);
      Async as=new Async(getActivity(),grd);
      as.execute(Sam_URL);
  
      mProgressBar = (ProgressBar)rootView.findViewById(R.id.progressBar);
     // grd.setBackgroundColor(Color.CYAN);
      grd.setVerticalSpacing(7);
      grd.setHorizontalSpacing(7);
  
  
  
     grd.setOnItemClickListener(new AdapterView.OnItemClickListener() {
  
      @Override
      public void onItemClick(AdapterView&lt;?&gt; parent, View view, int position,
              long id) {
          // TODO Auto-generated method stub
  
          Intent intent=new Intent(getActivity(),KidsWear.class);
          intent.putExtra("pos", position+"");
          startActivity(intent);
  
      }
  });
  
      return rootView;
  }
  
  
  
  
  
  
  
  class Async extends AsyncTask&lt;String, Void, Integer&gt;{
      Context context;
      GridView gridView;
  
  
      public Async(Context context,GridView gridView) {
          // TODO Auto-generated constructor stub
  
          this.context=context;
          this.gridView=gridView;
      }
  
  
  
      @Override
      protected Integer doInBackground(String... params) {
          // TODO Auto-generated method stub
  
  
          Integer result = 0;
          try {
              // Create Apache HttpClient
              //HttpClient httpclient = new DefaultHttpClient();
              URL url = new URL(Sam_URL);
              URLConnection urlConnection = url.openConnection();
              InputStream in = new BufferedInputStream(
                      urlConnection.getInputStream());
  
              // int statusCode =
              // httpResponse.getStatusLine().getStatusCode();
  
              // 200 represents HTTP OK
              if (true) {
                  String response = streamToString(in);
                  parseResult(response);
                  result = 1; // Successful
              } else {
                  result = 0;       // "Failed
              }
          } catch (Exception e) {
  
          }
  
          return result;
  
  
  
      }
      String streamToString(InputStream stream) throws IOException {
          BufferedReader bufferedReader = new BufferedReader(
                  new InputStreamReader(stream));
          String line;
          String result = "";
          while ((line = bufferedReader.readLine()) != null) {
              result += line;
          }
  
          // Close stream
          if (null != stream) {
              stream.close();
          }
          return result;
      }
  
      @Override
      protected void onPostExecute(Integer result) {
          // TODO Auto-generated method stub
          super.onPostExecute(result);
  
  
          if (result == 1) {
  
      gridView.setAdapter(new MyAdapter(context,gridData));
  
      gridView.setVisibility(View.VISIBLE);
  
  
  
      }mProgressBar.setVisibility(View.GONE); 
  
      }   
  
  
  
      private void parseResult(String result) {
          try {
  
              Log.d("MainActivity", "JSON Result : " + result);
              JSONArray response = new JSONArray(result);
  
              for (int i = 0; i &lt; response.length(); i++)
  
              {
  
                  JSONObject obj = response.getJSONObject(i);
  
                  String Doc_name = obj.getString("documentName");
                  Log.d("documentName",Doc_name);
  
                  String Doc_file = obj.getString("documentFile");
              String Doc_content = obj.getString("documentContent");
  
              String Doc_offer=obj.getString("offer");
              String Doc_address=obj.getString("address");
  
                  //Log.d("documentName","JSON Result : " + result);
  
                  Pojo gd = new Pojo();
  
  
  
                  gd.setDocumentName(Doc_name);
  
                  gd.setDocumentFile(Doc_file);
                  gd.setOffer(Doc_offer);
  
                  gd.setDocumentContent(Doc_content);
                  gd.setAddress(Doc_address);
  
                  gridData.add(gd);
  
  
              }
  
  
          } catch (JSONException e) {
              e.printStackTrace();
          }
  
  
          }
  }
  </code></pre>
  
  <p>where below my log cat error please any one help me </p>
  
  <blockquote>
    <p>java.lang.NullPointerException: Attempt to invoke virtual method 'void
    android.widget.ProgressBar.setVisibility(int)' on a null object
    reference</p>
  </blockquote>