The downloaded image cannot be saved to the SD card.

Here the OutputStream path file could not be saved

package com.example;

import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class download extends Activity {

    public static final int DIALOG_DOWNLOAD_PROGRESS = 0;
    private Button startBtn;
    private ProgressDialog mProgressDialog;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        startBtn = (Button)findViewById(R.id.startBtn);
        startBtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                startDownload();
            }
        });
    }

    private void startDownload() {
        String url = "http://farm1.static.flickr.com/114/298125983_0e4bf66782_b.jpg";
        new DownloadFileAsync().execute(url);
    }
    @Override
    protected Dialog onCreateDialog(int id) {
        switch (id) {
        case DIALOG_DOWNLOAD_PROGRESS:
            mProgressDialog = new ProgressDialog(this);
            mProgressDialog.setMessage("Downloading file..");
            mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            mProgressDialog.setCancelable(false);
            mProgressDialog.show();
            return mProgressDialog;
        default:
            return null;
        }
    }

class DownloadFileAsync extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

    @Override
    protected String doInBackground(String... aurl) {
        int count;

    try {

    URL url = new URL(aurl[0]);
    URLConnection conexion = url.openConnection();
    conexion.connect();

    int lenghtOfFile = conexion.getContentLength();
    Log.d("ANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);

    InputStream input = new BufferedInputStream(url.openStream());
    OutputStream output = new FileOutputStream("/sdcard/some_photo_from_gdansk_poland.jpg");

    byte data[] = new byte[1024];

    long total = 0;

        while ((count = input.read(data)) != -1) {
            total += count;
            publishProgress(""+(int)((total*100)/lenghtOfFile));
            output.write(data, 0, count);
        }

        output.flush();
        output.close();
        input.close();
    } catch (Exception e) {}
    return null;

    }
    protected void onProgressUpdate(String... progress) {
         Log.d("ANDRO_ASYNC",progress[0]);
         mProgressDialog.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String unused) {
        dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
    }
}
}


Permission: 
   <uses-permission android:name="android.permission.INTERNET"/>