Download store and Read Images from sdcard in android

DownloadAndReadImage.java 
public class DownloadAndReadImage
{
    String strURL;
    int pos;
    Bitmap bitmap=null;
   
    // pass image url and Pos for example i:
    DownloadAndReadImage(String url,int position)
    {
        this.strURL=url;
        this.pos=position;
    }
   
    public Bitmap getBitmapImage()
    {
           downloadBitmapImage();
            return readBitmapImage();
    }
   
    void downloadBitmapImage()
    {
        InputStream input;
        try {
            URL url = new URL (strURL);
            input = url.openStream();
            byte[] buffer = new byte[1500];
            OutputStream output = new FileOutputStream ("/sdcard/"+pos+".png");
            try
            {    
                int bytesRead = 0;
                while ((bytesRead = input.read(buffer, 0, buffer.length)) >= 0)
                {
                    output.write(buffer, 0, bytesRead);
                }
            }
            finally
            {
                output.close();
                buffer=null;
            }
        }
        catch(Exception e)
        {
            Toast.makeText(getApplicationContext(),e.toString(), Toast.LENGTH_LONG).show();
        }
    }
   
    Bitmap readBitmapImage()
    {
        String imageInSD = "/sdcard/mac/"+strURL;
        BitmapFactory.Options bOptions = new BitmapFactory.Options();
        bOptions.inTempStorage = new byte[16*1024];
               
            bitmap = BitmapFactory.decodeFile(imageInSD,bOptions);
           
        return bitmap;
    }
       
}


MainActivity.java
public class MainActivity extends Activity {
   @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

String imgURL="http://4.bp.blogspot.com/-GDG0jraKnFI/TzZHQ5At0zI/AAAAAAAAAEY/TPl4U6vm5lw/s1600/android-example-code-demo-program.jpg";

       ImageView  ivCurrent;
      ivCurrent = (ImageView)findViewById(R.id.imageview1);

     // calling DownloadAndReadImage class to load and save image in sd card

          DownloadAndReadImage dImage= new DownloadAndReadImage(imgURL,1);
           
ivCurrent.setImageBitmap(dImage.getBitmapImage());
 }
}