Interaccion Con WorkerService

ClientWorker

package directorio.actividades.test;

import java.io.File;

import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.util.Log;
import android.view.Menu;
import android.widget.Toast;

public class MainActivity extends Activity {
	
	  Messenger messenger = null;
	
	  String holo = "Aun no termina";
	  
    private Handler handler = new Handler() {
        public void handleMessage(Message message) {
          Object path = message.obj;
          if (message.arg1 == RESULT_OK && path != null) {
        	  
        	  holo = "Termino bato lodo";
        	  
            Toast.makeText(MainActivity.this,
                "Downloaded" + path.toString(), Toast.LENGTH_LONG)
                .show();
          } else {
            Toast.makeText(MainActivity.this, "Download failed.",
                Toast.LENGTH_LONG).show();
          }

        };
      };
      
      private ServiceConnection conn = new ServiceConnection() {

    	  @Override
    	    public void onServiceConnected(ComponentName className, IBinder binder) {
    	      messenger = new Messenger(binder);

    	    }
    	  	@Override
    	    public void onServiceDisconnected(ComponentName className) {
    	      messenger = null;
    	    }
		
    	  };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Intent intent = new Intent(this, WorkService.class);
        // Create a new Messenger for the communication back
        Messenger messenger = new Messenger(handler);
        intent.putExtra("MESSENGER", messenger);
        startService(intent);
    
    }

    @Override
	protected void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
		  
		  File SDCardRoot = Environment.getExternalStorageDirectory();
			File file = new File(SDCardRoot, "Volta.db");
		  
			if(file.exists() && holo == "Termino bato lodo"){
				Toast.makeText(this, "Existe bato loco : O", Toast.LENGTH_SHORT).show();	
			}else{
				Toast.makeText(this, "Aun no termina bato loco... : O", Toast.LENGTH_SHORT).show();
			}
			
	}

}