noClassDefFound android

Question

Я пытаюсь отредактировать код gesturebuilder из образца андроида. В один прекрасный день я нашел это исключение noClassDefFound.

Журнал ошибок

04-04 02:13:51.278: E/AndroidRuntime(1002): FATAL EXCEPTION: main 
04-04 02:13:51.278: E/AndroidRuntime(1002): java.lang.NoClassDefFoundError:  android.os.AsyncTask 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at com.likith.gesturebuilder.GestureBuilderActivity.loadGestures(GestureBuilderActivity.java:250) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at com.likith.gesturebuilder.GestureBuilderActivity.onCreate(GestureBuilderActivity.java:168) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.os.Handler.dispatchMessage(Handler.java:99) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.os.Looper.loop(Looper.java:123) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at android.app.ActivityThread.main(ActivityThread.java:3683) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at java.lang.reflect.Method.invoke(Method.java:507) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
04-04 02:13:51.278: E/AndroidRuntime(1002):  at dalvik.system.NativeStart.main(Native Method) 

Код

@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) 
{ 
    super.onActivityResult(requestCode, resultCode, data); 

    if (resultCode == RESULT_OK) 
    { 
     switch (requestCode) 
     { 
      case REQUEST_NEW_GESTURE: 
       loadGestures(); 
       break; 
     } 
    } 
} 

private void loadGestures() 
{ 
    if (mTask != null && mTask.getStatus() != GesturesLoadTask.Status.FINISHED) 
    { 
     mTask.cancel(true); 
    } 

    mTask = (GesturesLoadTask) new GesturesLoadTask().execute(); 
} 


public class GesturesLoadTask extends AsyncTask<Void, NamedGesture, Integer> 
{ 
    private int mThumbnailSize; 
    private int mThumbnailInset; 
    private int mPathColor; 

    @Override 
    protected void onPreExecute() 
    { 
     super.onPreExecute(); 

     final SharedPreferences pref= PreferenceManager.getDefaultSharedPreferences(getBaseContext()); 
     final Resources resources = getResources(); 
     //mPathColor = resources.getColor(R.color.gesture_color); 
     mPathColor = pref.getInt("gesture_color", Color.parseColor("#ffe3a0")); 
     mThumbnailInset = (int) resources.getDimension(R.dimen.gesture_thumbnail_inset); 
     mThumbnailSize = (int) resources.getDimension(R.dimen.gesture_thumbnail_size); 

     findViewById(R.id.addButton).setEnabled(false);  

     mAdapter.setNotifyOnChange(false);    
     mAdapter.clear(); 
    } 

    @Override 
    protected Integer doInBackground(Void... params) 
    { 
     if (isCancelled()) return STATUS_CANCELLED; 
     if (!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) 
     { 
      return STATUS_NO_STORAGE; 
     } 

     final GestureLibrary store = sStore; 

     if (store.load()) 
     { 
      for (String name : store.getGestureEntries()) 
      { 
       if (isCancelled()) break; 

       for (Gesture gesture : store.getGestures(name)) 
       { 
        final Bitmap bitmap = gesture.toBitmap(mThumbnailSize, mThumbnailSize,mThumbnailInset, mPathColor); 
        final NamedGesture namedGesture = new NamedGesture(); 
        namedGesture.gesture = gesture; 
        namedGesture.name = name; 

        mAdapter.addBitmap(namedGesture.gesture.getID(), bitmap); 
        publishProgress(namedGesture); 
       } 
      } 
      return STATUS_SUCCESS; 
     } 
     return STATUS_NOT_LOADED; 
    } 

    @Override 
    protected void onProgressUpdate(NamedGesture... values) 
    { 
     super.onProgressUpdate(values); 

     final GesturesAdapter adapter = mAdapter; 
     adapter.setNotifyOnChange(false); 

     for (NamedGesture gesture : values) 
     { 
      adapter.add(gesture); 

      tap_info.setVisibility(View.VISIBLE); 
     } 

     adapter.sort(mSorter); 
     adapter.notifyDataSetChanged(); 
    } 

    @Override 
    protected void onPostExecute(Integer result) 
    { 
     super.onPostExecute(result); 

     if (result == STATUS_NO_STORAGE) 
     { 
      getListView().setVisibility(View.GONE); 
      mEmpty.setVisibility(View.VISIBLE); 
      mEmpty.setText(getString(R.string.gestures_error_loading,mStoreFile.getAbsolutePath())); 
     } 
     else 
     { 
      findViewById(R.id.addButton).setEnabled(true); 
      checkForEmpty(); 
     } 
    } 
} 

Что вы имеете в виду исключения noClassDefFound и способы ее решения. Пожалуйста, помогите.

Answer 1

A NoClassException означает, что класс, в данном случае AsyncTask, не может быть найден нигде в пути к классам.

заказ некоторые из решений по этой теме: Android: NoClassDefFoundError android.os.AsyncTask

Один из которых загружен класс вручную с помощью Class.forName (String) вызова.