前后端分离文件下载接口定义

/**
     * 根据url获取文件流 byte[]
     *
     * @param url
     * @return byte[]
     * @throws IOException
     */
    public byte[] getFile(String url) throws IOException {
        URL urlConet = new URL(url);
        HttpURLConnection con = (HttpURLConnection) urlConet.openConnection();
        con.setRequestMethod("GET");
        con.setConnectTimeout(4 * 1000);
        InputStream inputStream = con.getInputStream();
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[2048];
        int len = 0;
        while ((len = inputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, len);
        }
        inputStream.close();
        byte[] data = byteArrayOutputStream.toByteArray();
        byteArrayOutputStream.close();
        return data;
    }