Java 从远程数据库的文件夹下载图像，并在GridView中打印它们

以下代码不会打印活动中从数据库下载的图像。 我不明白我错在哪里，没有崩溃

提前感谢那些帮助我的人

MainActivity.java：

公共类MainActivity扩展了活动{

//ImageAdapter imageAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Log.i("MainActivity", "dopo xml");

    GridView grid = (GridView) findViewById(R.id.gridView);
   //imageAdapter = new ImageAdapter(this);
    final ArrayAdapter<DatiServer> adapter = new ImageAdapter(this);
    grid.setAdapter(adapter);
    Log.i("MainActivity", "connection");

    new Connection(adapter).execute();


}

}

ImageAdapter.java

public class ImageAdapter extends ArrayAdapter<DatiServer>

public class DatiServer {

private String ImageUrl;

public String getImageUrl()
{
    Log.i("DatiServer", "getImageUrl()");
    Log.d("DatiServer", "valore getImageUrl " + ImageUrl );
    return ImageUrl;
}

public String getTesto()
{
    Log.i("DatiServer", "getImageUrl()");
    Log.d("DatiServer", "valore getImageUrl " + ImageUrl );
    return ImageUrl;
}

public void setImageUrl(String ImageUrl)
{
    Log.i("DatiServer", "setImageUrl");
    this.ImageUrl = ImageUrl;
    Log.d("DatiServer", "valore setImageUrl " + ImageUrl );

}

public class ImageAdapter extends ArrayAdapter<DatiServer>

public ImageAdapter(Context context)
{
    super(context, 0, new ArrayList<DatiServer>());
}



@Override
public View getView(int position, View convertView, ViewGroup parent)
{

    Log.i ("ImageAdapter", "dentro getView()");


    ImageView imageView = (ImageView) convertView;
    if (imageView == null)
    {
        imageView = new ImageView(getContext());
        Log.i ("ImageAdapter", "imageView(getContext()) " + imageView);

        imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(8, 8, 8, 8);
        //imageView.setGravity(Gravity.CENTER);
        //imageView.setLines(1);
    }
    DatiServer datiserver  = getItem(position);
    imageView.setImageBitmap(downloadBitmap(datiserver.getImageUrl()));
    //imageView.setImageResource(R.drawable.img1);
    Log.i ("ImageAdapter", "imageView " + imageView);

    return imageView;


}

private Bitmap downloadBitmap(String fileUrl)
{

    Log.i ("ImageAdapter", "dentro downloadBitmap fileUrl " + fileUrl);

    InputStream is = null;
    try
    {
        HttpURLConnection conn = (HttpURLConnection) new URL(fileUrl).openConnection();
        conn.connect();
        is = conn.getInputStream();
        return BitmapFactory.decodeStream(is);
    }
    catch (MalformedURLException e)
    {
    }
    catch (IOException e)
    {
    }
    finally
    {
        if (is != null)
            try
            {
                is.close();
            }
            catch (IOException e)
            {
            }
    }
    return null;
}

 11-28 14:04:42.134: I/MainActivity(896): dopo xml
 11-28 14:04:42.144: I/MainActivity(896): connection
 11-28 14:04:42.197: I/MainActivity(896): diInBackground
 11-28 14:04:42.534: I/Choreographer(896): Skipped 172 frames!  The application may be    doing too much work on its main thread.
 11-28 14:04:42.544: D/gralloc_goldfish(896): Emulator without GPU emulation det ected.
 11-28 14:04:42.764: I/Choreographer(896): Skipped 141 frames!  The application may be doing too much work on its main thread.
 11-28 14:04:43.644: D/Connection(896): vaolori di response:       org.apache.http.message.BasicHttpResponse@40d2d900
 11-28 14:04:43.644: I/MainActivity(896): leggiDati
 11-28 14:04:43.644: D/Log_tag(896): vaolori di dati: org.apache.http.message.BasicHttpResponse@40d2d900
 11-28 14:04:43.684: I/Dopo inputStream(896): fine while leggi dati 
 11-28 14:04:43.684: I/Dopo inputStream(896): [{"immagine":"images\/img1.jpeg" }]
 11-28 14:04:43.684: D/Connection(896): vaolori di dati dopo chiamata leggiDati: 
 11-28 14:04:43.684: D/Connection(896): [{"immagine":"images\/img1.jpeg"}]
 11-28 14:04:43.684: D/Connection(896): vaolori di dati dopo try http: 
 11-28 14:04:43.684: D/Connection(896): [{"immagine":"images\/img1.jpeg"}]
 11-28 14:04:43.684: I/Connection(896): Json
 11-28 14:04:43.684: D/Connection(896): vaolori di dati che vanno dell'oggetto json: 
 11-28 14:04:43.684: D/Connection(896): [{"immagine":"images\/img1.jpeg"}]
 11-28 14:04:43.684: I/Connection(896): JSONObject
 11-28 14:04:43.704: D/Connection(896): vaolori jArray:  [{"immagine":"images\/img1.jpeg"}]
 11-28 14:04:43.714: D/Connection(896): jArray i 1
 11-28 14:04:43.714: I/DatiServer(896): setImageUrl
 11-28 14:04:43.724: D/DatiServer(896): valore setImageUrl images/img1.jpeg
 11-28 14:04:43.724: I/Connection(896): onProgressUpdate
 11-28 14:04:43.724: I/Connection(896): onProgressUpdate  it.wss.prova.DatiServer@40d31e80
 11-28 14:04:43.764: I/ImageAdapter(896): dentro getView()
 11-28 14:04:43.774: I/ImageAdapter(896): imageView(getContext()) android.widget.ImageView{40d32768 V.ED.... ........ 0,0-0,0}
 11-28 14:04:43.774: I/DatiServer(896): getImageUrl()
 11-28 14:04:43.774: D/DatiServer(896): valore getImageUrl images/img1.jpeg
 11-28 14:04:43.784: I/ImageAdapter(896): dentro downloadBitmap fileUrl images/img1.jpeg
 11-28 14:04:43.794: I/ImageAdapter(896): imageView android.widget.ImageView{40d32768 V.ED.... ......I. 0,0-0,0}
 11-28 14:04:43.814: I/ImageAdapter(896): dentro getView()
 11-28 14:04:43.814: I/DatiServer(896): getImageUrl()
 11-28 14:04:43.814: D/DatiServer(896): valore getImageUrl images/img1.jpeg
 11-28 14:04:43.814: I/ImageAdapter(896): dentro downloadBitmap fileUrl  images/img1.jpeg
 11-28 14:04:43.824: I/ImageAdapter(896): imageView android.widget.ImageView{40d32768 V.ED.... ......I. 0,0-0,0}
 11-28 14:33:37.945: D/dalvikvm(896): GC_CONCURRENT freed 134K, 10% free 2617K/2892K, paused 8ms+5ms, total 85ms