Rss提要不显示图像，空指针异常

Question

我正在尝试使用图像构建一个rss阅读器，我能够获取这些提要但不能获取这些提要的图像，我已经标记了使用 * 给出Null指针异常的行，求助，这是我的代码，谢谢。

public View getView(int position, View convertView, ViewGroup parent) {
        View vi = convertView;

        if (convertView == null) {
            vi = inflater.inflate(R.layout.row, null);
            holder = new ViewHolder();
            holder.label = (TextView) vi.findViewById(R.id.title);
            holder.addr = (TextView) vi.findViewById(R.id.details);
            holder.image = (ImageView) vi.findViewById(R.id.thumb);
            vi.setTag(holder);
        } else
            holder = (ViewHolder) vi.getTag();

        holder.label.setText(data.get(position).getTitle());
        holder.addr.setText(data.get(position).getPubDate());
       // imageLoader.DisplayImage((data.get(position).getThumbnail()), holder.image);

        URL url = null;
        try {
            url = new URL((data.get(position).getImage()));
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        InputStream content = null;
        try {
            ***content = (InputStream)url.getContent();***
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Drawable d = Drawable.createFromStream(content , "src"); 
        Bitmap mIcon1 = null;
         try {
             mIcon1 =
                    BitmapFactory.decodeStream(url.openConnection().getInputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
        holder.image.setImageBitmap(Bitmap.createScaledBitmap(mIcon1, 72, 72,true));


        return vi;
    }

}

logcat输出：

error log
06-21 07:16:33.270: E/AndroidRuntime(402): FATAL EXCEPTION: main
06-21 07:16:33.270: E/AndroidRuntime(402): java.lang.NullPointerException
06-21 07:16:33.270: E/AndroidRuntime(402):  at com.xmlparse.EfficientAdapter.getView(EfficientAdapter.java:91)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.AbsListView.obtainView(AbsListView.java:1315)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.ListView.makeAndAddView(ListView.java:1727)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.ListView.fillDown(ListView.java:652)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.ListView.fillFromTop(ListView.java:709)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.ListView.layoutChildren(ListView.java:1580)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.AbsListView.onLayout(AbsListView.java:1147)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.View.layout(View.java:7035)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1249)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1125)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1042)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.View.layout(View.java:7035)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.View.layout(View.java:7035)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1249)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1125)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1042)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.View.layout(View.java:7035)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.View.layout(View.java:7035)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.ViewRoot.performTraversals(ViewRoot.java:1045)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1727)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.os.Handler.dispatchMessage(Handler.java:99)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.os.Looper.loop(Looper.java:123)
06-21 07:16:33.270: E/AndroidRuntime(402):  at android.app.ActivityThread.main(ActivityThread.java:4627)
06-21 07:16:33.270: E/AndroidRuntime(402):  at java.lang.reflect.Method.invokeNative(Native Method)
06-21 07:16:33.270: E/AndroidRuntime(402):  at java.lang.reflect.Method.invoke(Method.java:521)
06-21 07:16:33.270: E/AndroidRuntime(402):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
06-21 07:16:33.270: E/AndroidRuntime(402):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
06-21 07:16:33.270: E/AndroidRuntime(402):  at dalvik.system.NativeStart.main(Native Method)