无法将图像从 url 转换为字节数组

Question

我是 android 新手，我需要将图像从 url 保存到 db 并从 db 中获取。我将图像从链接转换为字节数组，但出现以下错误：

无法解析 ByteArrayBuffer

这是代码：

 private byte[] getLogoImage(String url){
    try {
             URL imageUrl = new URL(url);
             URLConnection ucon = imageUrl.openConnection();

             InputStream is = ucon.getInputStream();
             BufferedInputStream bis = new BufferedInputStream(is);

             ByteArrayBuffer baf = new ByteArrayBuffer(500);
             int current = 0;
             while ((current = bis.read()) != -1) {
                     baf.append((byte) current);
             }

             return baf.toByteArray();
     } catch (Exception e) {
             Log.d("ImageManager", "Error: " + e.toString());
     }
     return null;
}

Answer 1

如下更新您的方法getLogoImage()。

使用AsyncTask 并从doInBackground() 调用此方法。

这是工作代码。试试这个：

private byte[] getLogoImage(String url) {

    try {

        URL imageUrl = new URL(url);
        URLConnection ucon = imageUrl.openConnection();

        InputStream is = ucon.getInputStream();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int read = 0;

        while ((read = is.read(buffer, 0, buffer.length)) != -1) {
            baos.write(buffer, 0, read);
        }

        baos.flush();

        return  baos.toByteArray();

    } catch (Exception e) {
        Log.d("ImageManager", "Error: " + e.toString());
    }

    return null;
}

Answer 2

使用这个

BitmapFactory.Options options = null;
            options = new BitmapFactory.Options();
            options.inSampleSize = 3;
            Bitmap bitmap = BitmapFactory.decodeFile(url,
                    options);
            ByteArrayOutputStream stream = new ByteArrayOutputStream();

            bitmap.compress(Bitmap.CompressFormat.PNG, 50, stream);
            byte[] byte_arr = stream.toByteArray();

Answer 3

这样试试

Bitmap bm = null;
   InputStream is = conn.getInputStream();
        BufferedInputStream bis = new BufferedInputStream(is);
        bm = BitmapFactory.decodeStream(bis);
       byte[] imageArray = getBytes(bm);

然后使用下面的方法

  public static byte[] getBytes(Bitmap bitmap) {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 90, stream);
    return stream.toByteArray();
}