图片URL转Base64编码

@Slf4j
public class UrlToBase64Util {
   /**
    * 图片URL转Base64编码
    * @param imgUrl 图片URL
    * @return Base64编码
    */
   public static String imageUrlToBase64(String imgUrl) {
      URL url = null;
      InputStream is = null;
      ByteArrayOutputStream outStream = null;
      HttpURLConnection httpUrl = null;

      try {
         url = new URL(imgUrl);
         httpUrl = (HttpURLConnection) url.openConnection();
         httpUrl.connect();
         httpUrl.getInputStream();

         is = httpUrl.getInputStream();
         outStream = new ByteArrayOutputStream();

         //创建一个Buffer字符串
         byte[] buffer = new byte[1024];
         //每次读取的字符串长度，如果为-1，代表全部读取完毕
         int len = 0;
         //使用输入流从buffer里把数据读取出来
         while( (len = is.read(buffer)) != -1 ){
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
            outStream.write(buffer, 0, len);
         }

         // 对字节数组Base64编码
         return encode(outStream.toByteArray());
      } catch (Exception e) {
         log.error("图片地址转base64值异常",e);
         e.printStackTrace();
      } finally {
         try {
            if(is != null) {
               is.close();
            }
            if(outStream != null) {
               outStream.close();
            }
            if(httpUrl != null) {
               httpUrl.disconnect();
            }
         } catch (Exception e) {
            e.printStackTrace();
         }
      }
      return null;
   }

   /**
    * 图片转字符串
    * @param image 图片Buffer
    * @return Base64编码
    */
   public static String encode(byte[] image){
      BASE64Encoder decoder = new BASE64Encoder();
      return replaceEnter(decoder.encode(image));
   }

   /**
    * 字符替换
    * @param str 字符串
    * @return 替换后的字符串
    */
   public static String replaceEnter(String str){
      String reg ="[\n-\r]";
      Pattern p = Pattern.compile(reg);
      Matcher m = p.matcher(str);
      return m.replaceAll("");
   }
}