public String downloadImages(String serverUrl,String directory)
    {

        if (serverUrl == null)
            return null;

        String LocalFilePath=serverUrl.substring(serverUrl.lastIndexOf("/")+1, serverUrl.length());
        File file =  new File(directory, LocalFilePath);
         if (!file.exists())
         {
                int bytesread = 0;
                byte[] bytes = new byte[1024];
                InputStream strm = null;
                HttpResponse response = null;
                HttpEntity entity = null;
                String LocalFile = null;
                FileOutputStream foStream;
                BufferedOutputStream writer = null;
                try {
                    DefaultHttpClient httpclient = new DefaultHttpClient();
                    serverUrl = serverUrl.replace(" ", "%20");
                    HttpGet httpget = new HttpGet(serverUrl);

                    response = httpclient.execute(httpget);

                    if (response == null)
                    {
                        return null;
                    }
                    entity = response.getEntity();
                    strm = entity.getContent();
                    File dire = new File(directory);
                    if (!dire.isDirectory())
                    {
                        dire.mkdirs();
                    }
                    LocalFile = directory+LocalFilePath;
                    directory = null;
                    foStream = new FileOutputStream(LocalFile);
                    writer = new BufferedOutputStream(foStream);

                    do
                    {
                        bytesread = strm.read(bytes, 0, bytes.length);
                        if(bytesread > 0)
                        {
                            writer.write(bytes, 0, bytesread);
                            writer.flush();
                        }
                    } while (bytesread > 0);

                    writer.close();
                    foStream.close();

                    strm.close();
                    return LocalFile;
                }
                catch(Exception e)
                {
                    file.delete();
                    e.printStackTrace();
                    return null;
                }
         }
         else
         {
             return "file exist";
         }
    }