title: AsyncTask crashes in doInBackground()
body: <p>You see I'm trying to load some data on this adapter, but I can not make a AsyncTask to show a progress dialog so.</p>
  
  <p>This is the complete code of the program it gives me error. I completely revised so do not edit any of the UI.</p>
  
  <pre><code>public class MatchNowGames extends Activity {
  Games games = new Games();
  Iterator iterador;
  private ProgressDialog dialog;
  GamesArrayAdapter adapter;
  ListView lv;
  public void onCreate(Bundle savedInstanceState) {       
      super.onCreate(savedInstanceState);        
      // INCIO PROGRAMA        
      setContentView(R.layout.games_list);
      lv = (ListView) this.findViewById(R.id.gamesLV);
      // Creamos el thread
      dialog = new ProgressDialog(this);
      dialog.setMessage("Cargando...");
      dialog.setTitle("Progreso");
      dialog.setCancelable(false);
  
      // INIT VARIABLES
      new CargandoJuegos().execute(); 
      adapter = new GamesArrayAdapter(App.context().getApplicationContext(), R.layout.games_list, games.getGames());      
  
  
  }
  private class CargandoJuegos extends AsyncTask&lt;Void, Void, Void&gt;{
      protected void onPreExecute() {
              dialog.show();
              }
  
       protected Void doInBackground(Void... urls) {
           // AÑADIMOS LOS JUEGOS
          try {
              games.addGames(MatchNow.serverGames);
              try {
                  Thread.sleep(5000);
              } catch (InterruptedException e) {
  
                  e.printStackTrace();
              }
          } catch (JSONException e) {}
          return null;
       }
       protected void onPostExecute(Void unused) {
           dialog.dismiss();
           lv.setAdapter(adapter);
       }
  
  
    }
  
  }
  </code></pre>
  
  <p>And this is what we should do while displaying the progressdialog:</p>
  
  <pre><code>// Start progress dialog
      try {
              games.addGames(MatchNow.serverGames);
          } catch (JSONException e) {
              e.printStackTrace();
          }
      // Finish progress dialog
      GamesArrayAdapter adapter = new GamesArrayAdapter(App.context().getApplicationContext(), R.layout.games_list, games.getGames());
      ListView lv = (ListView) this.findViewById(R.id.gamesLV);
      lv.setAdapter(adapter);
  </code></pre>
  
  <p>Thank you very much in advance =)</p>
  
  <p>The logcat:</p>
  
  <pre><code>09-07 02:18:07.916: D/AndroidRuntime(890): Shutting down VM
  09-07 02:18:07.916: W/dalvikvm(890): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
  09-07 02:18:07.926: E/AndroidRuntime(890): Uncaught handler: thread main exiting due to uncaught exception
  09-07 02:18:07.936: E/AndroidRuntime(890): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{match.now.play/match.now.play.MatchNowGames}: java.lang.NullPointerException
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2417)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.access$2200(ActivityThread.java:119)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.os.Handler.dispatchMessage(Handler.java:99)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.os.Looper.loop(Looper.java:123)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.main(ActivityThread.java:4363)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.reflect.Method.invokeNative(Native Method)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.reflect.Method.invoke(Method.java:521)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at dalvik.system.NativeStart.main(Native Method)
  09-07 02:18:07.936: E/AndroidRuntime(890): Caused by: java.lang.NullPointerException
  09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.Activity.findViewById(Activity.java:1612)
  09-07 02:18:07.936: E/AndroidRuntime(890):  at match.now.play.MatchNowGames.&lt;init&gt;(MatchNowGames.java:40)
  </code></pre>
  
  <p>I solved the problem of the line 1612, was an oversight. Logcat really gives problems. Sorry for the inconvenience.</p>
  
  <pre><code>    09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.Class.newInstanceImpl(Native Method)
      09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.Class.newInstance(Class.java:1479)
      09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
      09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2409)
      09-07 02:18:07.936: E/AndroidRuntime(890):  ... 11 more
  
  
  09-07 02:34:31.486: D/dalvikvm(930): GC freed 404 objects / 23688 bytes in 60ms
  09-07 02:34:32.976: I/global(930): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
  09-07 02:34:32.986: I/System.out(930): {"games":[{"id":"1","image":"http:\/\/cibermaniacos.com\/images\/stories\/call_of_duty_modern_warfare_3_desvelado_dest01.jpg","name":"Call Of Duty MW3","descrip":"","modes":[{"id":"1","name":"1vs1","mode_icon":"none"},{"id":"2","name":"2vs2","mode_icon":"none"}],"console":"PS3,XBOX"},{"id":"2","image":"http:\/\/www.hry-na-mobil.eu\/data\/ikonky\/hry-na-mobil-eu\/46801\/call-of-duty-world-at-war-codww-1000x1000jpg-12.png","name":"Prueba","descrip":"afafs","modes":[{"id":"1","name":"1vs1","mode_icon":"none"},{"id":"2","name":"2vs2","mode_icon":"none"}],"console":"steam,PS3"},{"id":"4","image":"http:\/\/cibermaniacos.com\/images\/stories\/call_of_duty_modern_warfare_3_desvelado_dest01.jpg","name":"Call Of Duty MW2","descrip":"AWDAWD","modes":[{"id":"1","name":"1vs1","mode_icon":"none"},{"id":"2","name":"2vs2","mode_icon":"none"}],"console":"steam,PS3"}]}                  
  09-07 02:34:33.036: I/System.out(930): Call Of Duty MW2
  09-07 02:34:33.046: I/System.out(930): Call Of Duty MW3
  09-07 02:34:33.068: W/dalvikvm(930): threadid=15: thread exiting with uncaught exception (group=0x4001b188)
  09-07 02:34:33.068: E/AndroidRuntime(930): Uncaught handler: thread AsyncTask #1 exiting due to uncaught exception
  09-07 02:34:33.086: E/AndroidRuntime(930): java.lang.RuntimeException: An error occured while executing doInBackground()
  09-07 02:34:33.086: E/AndroidRuntime(930):  at android.os.AsyncTask$3.done(AsyncTask.java:200)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.lang.Thread.run(Thread.java:1096)
  09-07 02:34:33.086: E/AndroidRuntime(930): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
  09-07 02:34:33.086: E/AndroidRuntime(930):  at android.os.Handler.&lt;init&gt;(Handler.java:121)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at android.app.Activity.&lt;init&gt;(Activity.java:673)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.functions.Game.&lt;init&gt;(Game.java:52)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.functions.Games.addGames(Games.java:58)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.MatchNowGames$CargandoJuegos.doInBackground(MatchNowGames.java:67)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.MatchNowGames$CargandoJuegos.doInBackground(MatchNowGames.java:1)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at android.os.AsyncTask$2.call(AsyncTask.java:185)
  09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
  09-07 02:34:33.086: E/AndroidRuntime(930):  ... 4 more
  </code></pre>