java.lang.RuntimeException: Se produjo un error durante la ejecución de doInBackground()

Question

A veces me sale este error accidente en mi aplicación

java.lang.RuntimeException: An error occured while executing doInBackground() 

Ésta es la LogCat completo:

java.lang.RuntimeException: An error occured while executing doInBackground() 
at android.os.AsyncTask$3.done(AsyncTask.java:200) 
at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274) 
at java.util.concurrent.FutureTask.setException(FutureTask.java:125) 
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308) 
at java.util.concurrent.FutureTask.run(FutureTask.java:138) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 
at java.lang.Thread.run(Thread.java:1019) 
Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 
at android.os.Handler.<init>(Handler.java:121) 
at android.widget.Toast.<init>(Toast.java:68) 
at android.widget.Toast.makeText(Toast.java:231) 
at kostas.menu.olympiakos.nea.loadFeed(nea.java:84) 
at kostas.menu.olympiakos.nea.access$1(nea.java:75) 
at kostas.menu.olympiakos.nea$BackgroundAsyncTask_nea.doInBackground(nea.java:242) 
at kostas.menu.olympiakos.nea$BackgroundAsyncTask_nea.doInBackground(nea.java:1) 
at android.os.AsyncTask$2.call(AsyncTask.java:185) 
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306) 
... 4 more 

y este es mi código de clase .nea:

package kostas.menu.olympiakos; 


import java.io.IOException; 
import java.io.InputStream; 
import java.net.MalformedURLException; 
import java.net.URL; 
import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.List; 

import android.app.Dialog; 
import android.app.ListActivity; 
import android.app.ProgressDialog; 
import android.content.Context; 
import android.content.Intent; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.net.ConnectivityManager; 
import android.net.NetworkInfo; 
import android.net.Uri; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.Window; 
import android.view.animation.AlphaAnimation; 
import android.view.animation.Animation; 
import android.view.animation.AnimationSet; 
import android.view.animation.LayoutAnimationController; 
import android.view.animation.TranslateAnimation; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 
import android.widget.TextView; 
import android.widget.Toast; 


public class nea extends ListActivity{ 
    private List<Message> messages; 




    List<String> des = new ArrayList<String>();//to prosthesa gia na anoigei to keimeno sto alert 
    List<String> text = new ArrayList<String>();//to prosthesa gia na anoigei o titlos sto alert 
    List<URL> url = new ArrayList<URL>();//to prosthesa gia to koumpi pou pigainei sto link 

    List<String> imgl = new ArrayList<String>();//to prosthesa gia na anoigei to keimeno sto alert 

    @Override 
    public void onCreate(Bundle icicle) { 
     super.onCreate(icicle); 
     setContentView(R.layout.main2); 

     if(isInternetOn()) { 
      new BackgroundAsyncTask_nea().execute(); 
      }else{ 
      Toast.makeText(nea.this,R.string.no_connection, Toast.LENGTH_SHORT).show(); 
      finish(); 
      } 



    } 


    private void loadFeed(AsyncTask<Void, Void, Void> asyncTask){ 
     try{ 
      BaseFeedParser parser = new BaseFeedParser(); 
      messages = parser.parse(); 

      } 
     catch (Throwable t){ 
       Log.e("OSFP.News",t.getMessage(),t); 

       Toast.makeText(nea.this, "Χρειάζεστε σύνδεση στο internet", 
         Toast.LENGTH_SHORT).show(); 
       finish(); 

      } 
    } 


    private void displayRss(){ 

     ArrayList<HashMap<String, String>> List_nea = new ArrayList<HashMap<String, String>>(messages.size()); 


     for (Message msg : messages){ 

      des.add(msg.getDescription());// keimeno 
      text.add(msg.getTitle());// titlos 
      url.add(msg.getLink());// link 
      imgl.add(msg.getImgLink()); 

     HashMap<String, String> map = new HashMap<String, String>(); 
     map.put("name", msg.getTitle()); 
     map.put("date", msg.getDate());  


     List_nea.add(map); 
     ListAdapter mSchedule = new SimpleAdapter(this, List_nea, R.layout.row, 
       new String[] {"name", "date"}, new int[] {R.id.TextView01, R.id.TextView02}); 
     this.setListAdapter(mSchedule); 
     } 

    AnimationSet set = new AnimationSet(true); 

    Animation animation = new AlphaAnimation(0.0f, 1.0f); 
    animation.setDuration(400); 
    set.addAnimation(animation); 

    animation = new TranslateAnimation(
     Animation.RELATIVE_TO_SELF, 0.0f,Animation.RELATIVE_TO_SELF, 0.0f, 
     Animation.RELATIVE_TO_SELF, -1.0f,Animation.RELATIVE_TO_SELF, 0.0f 
    ); 

    animation.setDuration(400); 
    set.addAnimation(animation); 
    LayoutAnimationController controller = new LayoutAnimationController(set, 0.5f); 
    ListView listViewn = getListView();   
    listViewn.setLayoutAnimation(controller); 

    } 



    protected void onListItemClick(ListView l, View v, final int position, long id) { 



     super.onListItemClick(l, v, position, id); 
     Dialog dialog = new Dialog(this); 
     String description = des.get(position).toString().replaceAll("\\<.*?>",""); 
     String imagee=imgl.get(position).toString(); 
     final URL link = url.get(position); 
     dialog.requestWindowFeature(Window.FEATURE_NO_TITLE); 
      dialog.setContentView(R.layout.single); 
      dialog.setCancelable(true); 
      Toast msg = Toast.makeText(nea.this, "The url is : "+imagee, Toast.LENGTH_LONG); 
      msg.show(); 
//xrisimopoiisa toast gia na elegxw poio link pernw apo to site 



      TextView title_dialog = (TextView) dialog.findViewById(R.id.title_dialog); 
      title_dialog.setText(text.get(position)); 


      TextView text = (TextView) dialog.findViewById(R.id.descr); 
      text.setText(description); 


      ImageView image1 = (ImageView) dialog.findViewById(R.id.image1); 


      try { 
       //where imageUrl is what you pulled out from the rss feed 
       Bitmap bitmap = BitmapFactory.decodeStream((InputStream)new URL(imagee).getContent()); 
       image1.setImageBitmap(bitmap); 
       } catch (MalformedURLException e) { 
       //log exception here 
       } catch (IOException e) { 
       //log exception here 
       }  
      Button btnt = (Button) dialog.findViewById(R.id.btnrss);//ti kanei to koumpi otan to patas gia to link 
      btnt.setOnClickListener(new View.OnClickListener() { 
       public void onClick (View view) { 

        Intent viewMessage = new Intent(Intent.ACTION_VIEW, Uri.parse(link.toExternalForm())); 
        startActivityForResult(viewMessage, 0); 

       } 

      });   

      dialog.show(); 
    } 

     //options menu 
    @Override 
    public boolean onCreateOptionsMenu(Menu menu2) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.menu2, menu2); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.refresh: 
      new BackgroundAsyncTask_nea().execute(); 
      break; 


     } 
     return true; 
    } 

    public class BackgroundAsyncTask_nea extends 
     AsyncTask<Void, Void, Void> { 
      private ProgressDialog dialog; 
     int myProgress; 

     @Override 
     protected void onPostExecute(Void result) { 

      displayRss(); 
      dialog.dismiss(); 

     } 

     @Override 
     protected void onPreExecute() { 
      // TODO Auto-generated method stub 
       dialog = ProgressDialog.show(nea.this, "", "Loading. Please wait...", true); 
      myProgress = 0; 
     } 

     protected void onProgressUpdate(Integer... progress) { 
      // TODO Auto-generated method stub 
      //super.onProgressUpdate(values); 

      dialog.setProgress(progress[0]); 
     } 

     @Override 
     protected Void doInBackground(Void... arg0) { 
      // TODO Auto-generated method stub 

      loadFeed(this); 
      return null; 
     } 



    } 


    public final boolean isInternetOn() { 
     ConnectivityManager connec = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); 
     // ARE WE CONNECTED TO THE NET 
     if (connec.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED || 
     connec.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTING || 
     connec.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING || 
     connec.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTED) { 
     // MESSAGE TO SCREEN FOR TESTING (IF REQ) 
     //Toast.makeText(this, connectionType + ” connected”, Toast.LENGTH_SHORT).show(); 
     return true; 
     } else if (connec.getNetworkInfo(0).getState() == NetworkInfo.State.DISCONNECTED || connec.getNetworkInfo(1).getState() == NetworkInfo.State.DISCONNECTED ) { 
     //System.out.println(“Not Connected”); 
     return false; 
     } 
     return false; 
     } 
} 

¿Por qué recibo este error ¿Cómo puedo resolverlo Gracias :)

??

EDIT:

Public void toast_doInBck(View view) { 
     // Do something long 
     Runnable runnable = new Runnable() { 
      @Override 
      public void run() { 
       for (int i = 0; i <= 10; i++) { 
        Toast.makeText(nea.this,R.string.no_connection, Toast.LENGTH_SHORT).show(); 
        handler.post(new Runnable() { 
         @Override 
         public void run() { 
         } 
        }); 
       } 
      } 
     }; 
     new Thread(runnable).start(); 
    } 

Edit2:

private void loadFeed(AsyncTask<Void, Void, Void> asyncTask){ 
     try{ 
      BaseFeedParser parser = new BaseFeedParser(); 
      messages = parser.parse(); 

      } 
     catch (Throwable t){ 
       Log.e("OSFP.News",t.getMessage(),t); 
Looper.prepare(); 
       Toast.makeText(nea.this, "Παρακαλώ προσπαθήστε αργότερα..", 
         Toast.LENGTH_SHORT).show(); 
       finish(); 
       Looper.loop(); 

      } 
    } 

Answer 1

que está mostrando un Toast en loadFeed que se llama en la parte doInBackground de su AsyncTask. No deberías acceder a la IU desde allí.

Answer 2

Esto es probablemente porque estás tratando de mostrar algo en doInBackground(). doInBackground se ejecuta en un subproceso de trabajo que no puede hacer ningún trabajo de UI (incluido mostrar Toasts, que es lo que estás haciendo). En su lugar, todo el trabajo de UI debe realizarse en onPostExecute().

Answer 3

Pienso En este código Toast problema maquillaje para usted,

catch (Throwable t){ 
       Log.e("OSFP.News",t.getMessage(),t); 

       Toast.makeText(nea.this, "Χρειάζεστε σύνδεση στο internet", 
         Toast.LENGTH_SHORT).show(); 
       finish(); 

      } 

Debido a que usted está tratando de hacer UI operation del subproceso de trabajo de AsyncTask esto nunca será permitido ..

ACTUALIZACIÓN: Si desea actualizar algo del doInBackGround() de AsyncTask use publishProgress(Progress...) y onProgressUpdate(Progress...).

Answer 4

No puede hacer ningún trabajo de GUI en una cadena de fondo. En su lugar, debe post a Runnable to a handler created in the GUI thread para ejecutar su Toast en el hilo correcto.

EDITAR: Dado que se eliminó la etiqueta de la tarea, voy a dar un esquema de cómo hacerlo;

• nuevo() up a Handler en su hilo GUI (onCreate es un buen lugar) y guárdelo en una variable miembro, diga "controlador".
• Mueva mostrando su Toast a Runnable (la clase anónima es bastante buena para esto)
• Para mostrar el brindis, haga un handler.post() con su Runnable como parámetro. Runnable se ejecutará en el hilo de GUI.

Para obtener un ejemplo completo, consulte this article.