title: I am receiving NullPointerException error after changing an activity to a fragment
body: <p>Below is the Logcat for the error that I am getting, <code>json_string = getActivity().getIntent().getExtras().getString( "json_data" );</code></p>
  
  <pre><code> 09-10 21:56:07.507 22129-22129/com.example.aids.a09application E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                       Process: com.example.aids.a09application, PID: 22129
                                                                                       java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
                                                                                           at com.example.aids.a09application.DisplayListView.onCreateView(DisplayListView.java:31)
                                                                                           at android.support.v4.app.Fragment.performCreateView(Fragment.java:2192)
                                                                                           at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1299)
                                                                                           at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1528)
                                                                                           at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1595)
                                                                                           at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:758)
                                                                                           at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2363)
                                                                                           at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2149)
                                                                                           at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2103)
                                                                                           at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2013)
                                                                                           at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:710)
                                                                                           at android.os.Handler.handleCallback(Handler.java:751)
                                                                                           at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                           at android.os.Looper.loop(Looper.java:154)
                                                                                           at android.app.ActivityThread.main(ActivityThread.java:6692)
                                                                                           at java.lang.reflect.Method.invoke(Native Method)
                                                                                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
                                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)
  </code></pre>
  
  <p>This is the Fragment below that will lead into another Fragment DisplayinListView, Using a fragment transaction found at the bottom of this code. Originally this was an intent as the DisplayinListView was an activity, however I have now changed it to a fragment, due to the Navigation drawer.  </p>
  
  <pre><code>public class StandingsList extends Fragment implements View.OnClickListener {
      //make member variable is Views
      Button mButton;
      Button mButton1;
      TextView mResult;
      String JSON_RESPONSE;
      String json_string;
      FragmentTransaction fragmentTransaction;
  
      ProgressDialog mProgressDialog;
  
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                               Bundle savedInstanceState) {
          // Inflate the layout for this fragment
          View view = inflater.inflate( R.layout.fragment_standings, container, false );
  
  
          //get reference of the views
          mButton = (Button) view.findViewById( R.id.button );
          mButton1 = (Button) view.findViewById( R.id.buttontwo );
          mResult = (TextView) view.findViewById( R.id.result );
          mButton1.setOnClickListener(this);
  
          //when button is clicked
          mButton.setOnClickListener( new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  //call the getJsonResponse method and fetch the response from the server
                  new getJsonResponse().execute();
              }
          } );
  
          return view;
      }
  
  
          public class getJsonResponse extends AsyncTask&lt;Void, Void, String&gt; {
              String serverUrl;
  
              public getJsonResponse() {
                  mProgressDialog = new ProgressDialog( getActivity() );
                  mProgressDialog.setMessage( "Please Wait" );
                  mProgressDialog.setTitle( "Processing" );
                  mProgressDialog.setCancelable( false );
              }
  
              @Override
              protected void onPreExecute() {
  
                  //set the url from we have to fetch the json response
                  // DO NOT ADD REAL IP.
                  serverUrl = "http://xx.xx.xx.xx/get_info.php";
                  mProgressDialog.show();
              }
  
              @Override
              protected String doInBackground(Void... params) {
                  try {
                      URL url = new URL( serverUrl );
                      HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                      InputStream inputStream = httpURLConnection.getInputStream();
                      BufferedReader bufferedReader = new BufferedReader( new InputStreamReader( inputStream ) );
                      StringBuilder stringBuilder = new StringBuilder();
  
                      while ((JSON_RESPONSE = bufferedReader.readLine()) != null) {
  
                          stringBuilder.append( JSON_RESPONSE + "\n" );
  
                      }
  
                      inputStream.close();
                      bufferedReader.close();
                      httpURLConnection.disconnect();
  
                      return stringBuilder.toString().trim();
  
                  } catch (MalformedURLException e) {
                      Log.e( TAG, "MalformedURLException: " + e ); //print exception message to log
                  } catch (IOException e) {
                      Log.e( TAG, "IOException: " + e ); //print exception message to log
                  }
                  return null;
              }
  
              @Override
              protected void onProgressUpdate(Void... values) {
                  super.onProgressUpdate( values );
              }
  
              @Override
              protected void onPostExecute(String result) {
                  //set the result which is returned by doInBackground() method to result textView
                  mResult.setText( result );
                  mProgressDialog.dismiss();
                  json_string = result;
              }
  
          }
  
              public void onClick(View view){
  
                  switch (view.getId()) {
                      case R.id.buttontwo:
                          fragmentTransaction = getFragmentManager().beginTransaction();
                          fragmentTransaction.replace( main_container, new DisplayListView());
                          fragmentTransaction.commit();
                          break;
  
                  }
  
  
              }
          }
  </code></pre>
  
  <p>This is the class where the error is, on line 31 - <code>json_string = getActivity().getIntent().getExtras().getString( "json_data" );</code></p>
  
  <p>This error has been only created since I converted this class to a Fragment from an activity.</p>
  
  <pre><code>public class DisplayListView extends Fragment {
  
      String json_string;
      JSONObject jsonObject;
      JSONArray jsonArray;
      StandingsAdapter standingsAdapter;
      ListView listView;
  
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                               Bundle savedInstanceState) {
          // Inflate the layout for this fragment
          View view = inflater.inflate( R.layout.display_list_view_layout, container, false );
          listView= (ListView) view.findViewById( R.id.ListViewParse );
          standingsAdapter = new StandingsAdapter(getActivity(),R.layout.row_layout);
          listView.setAdapter( standingsAdapter );
          json_string = getActivity().getIntent().getExtras().getString( "json_data" );
          try {
              jsonArray  = new JSONObject(json_string).getJSONArray("server_response");
  
  
              int count = 0;
  
              int driver_id, team_id, position, points;
              String firstName, lastName;
  
  
  
              while(count&lt;jsonArray.length())
              {
                  JSONObject JO = jsonArray.getJSONObject(count);
                  driver_id = JO.getInt( "Driver_id" );
                  team_id =JO.getInt( "Team_id" );
                  firstName = JO.getString( "First_name" );
                  lastName= JO.getString( "Last_name" );
                  position= JO.getInt( "Position" );
                  points = JO.getInt( "Points" );
  
                  Standings standings = new Standings(driver_id, team_id, firstName, lastName, position, points );
                  standingsAdapter.add( standings );
                  count++;
              }
  
          } catch (JSONException e) {
              e.printStackTrace();
          }
  
          return view;
      }
  
  }
  </code></pre>