Android RSS читатель, FATAL ERROR

Question

Я хочу создать простой RSS Reader, а вот мой фактический код:

public class MainActivity extends ListActivity { 

    List headlines; 
    List links; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     // Initializing instance variables 
     headlines = new ArrayList(); 
     links = new ArrayList(); 

     try { 
      URL url = new URL(
        "http://www.radiojudaicastrasbourg.fr/category/podcasts/linvite-de-la-redaction/feed/"); 

      XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 
      factory.setNamespaceAware(false); 
      XmlPullParser xpp = factory.newPullParser(); 

      // We will get the XML from an input stream 
      xpp.setInput(getInputStream(url), "UTF_8"); 

      /* 
      * We will parse the XML content looking for the "<title>" tag which 
      * appears inside the "<item>" tag. However, we should take in 
      * consideration that the rss feed name also is enclosed in a 
      * "<title>" tag. As we know, every feed begins with these lines: 
      * "<channel><title>Feed_Name</title>...." so we should skip the 
      * "<title>" tag which is a child of "<channel>" tag, and take in 
      * consideration only "<title>" tag which is a child of "<item>" 
      * 
      * In order to achieve this, we will make use of a boolean variable. 
      */ 
      boolean insideItem = false; 

      // Returns the type of current event: START_TAG, END_TAG, etc.. 
      int eventType = xpp.getEventType(); 
      while (eventType != XmlPullParser.END_DOCUMENT) { 
       if (eventType == XmlPullParser.START_TAG) { 

        if (xpp.getName().equalsIgnoreCase("item")) { 
         insideItem = true; 
        } else if (xpp.getName().equalsIgnoreCase("title")) { 
         if (insideItem) 
          headlines.add(xpp.nextText()); // extract the 
                  // headline 
        } else if (xpp.getName().equalsIgnoreCase("enclosure")) { 
         if (insideItem) 
          links.add(xpp.getAttributeValue(null, "url")); // extract 
                      // the 
                      // link 
                      // of 
                      // article 
        } 
       } else if (eventType == XmlPullParser.END_TAG 
         && xpp.getName().equalsIgnoreCase("item")) { 
        insideItem = false; 
       } 

       eventType = xpp.next(); // move to next element 
      } 

     } catch (MalformedURLException e) { 
      e.printStackTrace(); 
     } catch (XmlPullParserException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 

     // Binding data 
     ArrayAdapter adapter = new ArrayAdapter(this, 
       android.R.layout.simple_list_item_1, headlines); 

     setListAdapter(adapter); 

    } 

    public InputStream getInputStream(URL url) { 
     try { 
      return url.openConnection().getInputStream(); 
     } catch (IOException e) { 
      return null; 
     } 
    } 

    @Override 
    protected void onListItemClick(ListView l, View v, int position, long id) { 
     Uri uri = Uri.parse((String) links.get(position)); 
     Intent intent = new Intent(Intent.ACTION_VIEW, uri); 
     startActivity(intent); 
    } 
} 

При запуске приложения, он просто закрывается немедленно, и я не знаю, почему. Вот LogCat:

>09-12 17:09:06.065: E/AndroidRuntime(11394): FATAL EXCEPTION: main 
09-12 17:09:06.065: E/AndroidRuntime(11394): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.parserxml/com.example.parserxml.MainActivity}: android.os.NetworkOnMainThreadException 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2339) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2389) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.ActivityThread.access$600(ActivityThread.java:153) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1269) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.os.Handler.dispatchMessage(Handler.java:99) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.os.Looper.loop(Looper.java:137) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.ActivityThread.main(ActivityThread.java:5287) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at java.lang.reflect.Method.invokeNative(Native Method) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at java.lang.reflect.Method.invoke(Method.java:525) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:738) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at dalvik.system.NativeStart.main(Native Method) 
09-12 17:09:06.065: E/AndroidRuntime(11394): Caused by: android.os.NetworkOnMainThreadException 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at java.net.InetAddress.getAllByName(InetAddress.java:214) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpEngine.connect(HttpEngine.java:311) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at com.example.parserxml.MainActivity.getInputStream(MainActivity.java:95) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at com.example.parserxml.MainActivity.onCreate(MainActivity.java:44) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.Activity.performCreate(Activity.java:5201) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
09-12 17:09:06.065: E/AndroidRuntime(11394): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2293) 
09-12 17:09:06.065: E/AndroidRuntime(11394): ... 11 more 

Answer 1

Согласно Android Documentation

Исключение, которое генерируется, когда приложение пытается выполнить операцию в сети на своем главном потоке.

Это делается только для приложений, предназначенных для сотового SDK или выше. Приложениям, использующим более ранние версии SDK, разрешено создавать сети в своих основных потоках цикла событий, но в значительной степени обесценивается . См. Документ «Разработка для реагирования».

Вам необходимо выполнить свою сетевую операцию в другом потоке, а не в потоке пользовательского интерфейса.