如何从localhost服务器上下载Android上的多个图像？

Question

我创建了一个Android应用程序来从我的本地服务器下载图像，但我没能做到。我尝试了几次，但我没有成功。这是我创建的确切类的源代码，用于执行我想要的功能：

ArrayList<Bitmap> bitmapArray =  new ArrayList<Bitmap>(4);
public static  final String URL = "http://localhost/img/";
Button load_img;
ImageView imageview;
Bitmap bitmap;
ProgressDialog pDialog;
protected void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_monitor);

    load_img = (Button)findViewById(R.id.load);
    imageview = (ImageView)findViewById(R.id.img);
    load_img.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            new LoadImage().execute(new String[]{URL});
            //img.setImageBitmap(bitmapArray.ge);
        }
    });
}

private class LoadImage extends AsyncTask<String, Void, Bitmap> {


    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(Monitor.this);
        pDialog.setMessage("Fetching Images ....");
        pDialog.show();

    }
    protected Bitmap doInBackground(String... urls) {
            bitmap = null;
            for(String url : urls){
                bitmap = downloadImage(url);
            }

            //List<Bitmap> bitmap = new ArrayList<Bitmap>;
           // bitmap = BitmapFactory.decodeStream((InputStream)new URL(args[0]).getContent());
        return bitmap;
    }


    private Bitmap downloadImage(String arg0){

        bitmap = null;
        InputStream stream = null;
        BitmapFactory.Options bmOptions = new BitmapFactory.Options();
        bmOptions.inSampleSize = 1;

        try{
            stream = getHttpConnection(arg0);
            bitmap = BitmapFactory.decodeStream(stream, null,bmOptions);
            stream.close();
        }catch(Exception e){
            e.printStackTrace();
        }
        bitmapArray.add(bitmap);
        return  bitmap;
    }



    protected void onPostExecute(Bitmap result) {

        if(result != null){
            imageview.setImageBitmap(bitmap);
            pDialog.dismiss();
        }else{
            pDialog.dismiss();
            Toast.makeText(Monitor.this,"Failed in downloading the image", Toast.LENGTH_SHORT).show();
        }
    }

    //creating open connection
    private InputStream getHttpConnection(String urlString) throws IOException{
        InputStream stream = null;
        URL url = new URL(urlString);
        URLConnection connection = url.openConnection();

        try {
            HttpURLConnection httpConnection = (HttpURLConnection) connection;
            httpConnection.setRequestMethod("GET");
            httpConnection.connect();

            if(httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK){
                stream = httpConnection.getInputStream();
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        return stream;
    }
}

}