后台返回前台图片二进制byte[]数据，前台获取

后台
File img = new File(imgPath.toString());
FileInputStream inputStream = new FileInputStream(img);
byte[] bytes = new byte[inputStream.available()];
inputStream.read(bytes, 0, inputStream.available());

前台
this.pay.code_url = 'data:image/jpeg;base64,' + response.code_url