base64和byte[]相互转换

   /**
     * 上传图片获取图片base64码,然后解码,然后转成字节数组,以流的形式输出到本地
     * @return
     * @throws Exception
     */
    @RequestMapping(value = "/uploadYujhImg1", method = RequestMethod.POST)
    @ResponseBody
    public EntityServiceResponse> uploadYujhImg1(String fileImg) throws Exception {
        logger.info("uploadYujh"+fileImg);
        String imgBase64 = fileImg.replaceAll("data:image/png;base64,","");
        BASE64Decoder d = new BASE64Decoder();
        byte[] data = d.decodeBuffer(imgBase64);
        FileOutputStream os = new FileOutputStream("D:\\tupian\\d.jpg");
        os.write(data);
        os.close();
        return null;
    }
///

//读取本地图片输入流
//将图片文件转化为字节数组字符串，并对其进行Base64编码处理

   public static void  main (String arg[]) throws IOException {
        //读取本地图片输入流
        //将图片文件转化为字节数组字符串，并对其进行Base64编码处理
        String imgFile = "D:\\tupian\\a.jpg";//待处理的图片
        InputStream in = null;
        byte[] data = null;
        //读取图片字节数组
        try
        {
            in = new FileInputStream(imgFile);
            data = new byte[in.available()];
            in.read(data);
            in.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        //对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        System.out.println(encoder.encode(data));//返回Base64编码过的字节数组字符串
    }