java读取网络图片为byte数组

方式1

   /**
     * 获取网络图片的byte数组
     * @param imageUrl
     * @return
     */
public byte[] getImageBytes(String imageUrl) {
    try {
        URL url = new URL(imageUrl);
        try (InputStream inputStream = url.openStream(); ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
            byte[] buffer = new byte[4096];
            int n;
            while ((n = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, n);
            }
            return outputStream.toByteArray();
        }
    } catch (Exception e) {
        log.info("获取URL图片byte数组异常:{}",e);
        return null;
    }
}

方式2

/**
 * 获取网络图片的byte数组
 * @param imageUrl
 * @return
 */
public byte[] getImageBytes(String imageUrl) {
     ByteArrayOutputStream baos = null;
     try {
         URL u = new URL(imageUrl);
         BufferedImage image = ImageIO.read(u);
         //convert BufferedImage to byte array
         baos = new ByteArrayOutputStream();
         ImageIO.write(image, "jpg", baos);
         baos.flush();
         return baos.toByteArray();
     } catch (Exception e) {
         log.info("获取URL图片byte数组异常:{}",e);
     } finally {
         if (baos != null) {
             try {
                 baos.close();
             } catch (IOException e) {
             }
         }
     }
     return null;
}