Core Class Android

//package com.never.util;
import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.provider.MediaStore;
 class ScanSDReceiver extends BroadcastReceiver {
  private AlertDialog.Builder alertdialogbuilder = null;
  private AlertDialog alertdialog = null;
  private Cursor cursor;
  @Override
  public void onReceive(Context arg0, Intent arg1) {
    // TODO Auto-generated method stub
    String receiveaction = arg1.getAction();
    if (Intent.ACTION_MEDIA_SCANNER_STARTED.equals(receiveaction)) {
      alertdialogbuilder = new AlertDialog.Builder(arg0);
      alertdialogbuilder.setMessage("Message......");
      alertdialog = alertdialogbuilder.create();
      alertdialog.show();
      cursor = arg0.getContentResolver().query(
          MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
          new String[] { MediaStore.Audio.Media.TITLE,
              MediaStore.Audio.Media.DURATION,
              MediaStore.Audio.Media.ARTIST,
              MediaStore.Audio.Media._ID,
              MediaStore.Audio.Media.DISPLAY_NAME }, null, null,
          null);
    } else if (Intent.ACTION_MEDIA_SCANNER_FINISHED.equals(receiveaction)) {
      alertdialog.cancel();
    }
  }
}