Android从服务器下载的几个图像正在被破坏

Question

我使用的功能将图像从服务器下载到我的Android设备的内部存储器，功能是：

private void downloadFile(String myurl, String name) {
    // TODO Auto-generated method stub
    int count=0;

    try {

        URL url = new URL(myurl);
        URLConnection conexion = url.openConnection();
        conexion.connect();

        lenghtOfFile = conexion.getContentLength();
        Log.d("ANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);

        InputStream input = new BufferedInputStream(url.openStream());
        OutputStream output = new FileOutputStream(Environment.getExternalStorageDirectory().getAbsolutePath() + "/test library/"+name.replace(" ","")+".png");

        byte data[] = new byte[1024];

        total = 0;

            while ((count = input.read(data)) != -1) {
                total += count;
                publishProgress(""+(int)((total*100)/lenghtOfFile));

                output.write(data, 0, count);
            }

            output.flush();
            output.close();
            input.close();
        } catch (Exception e) {a=e.toString();}
}

我在服务器上有22个图像，问题是有些图像被下载为损坏的文件，请帮忙吗？