If you create your own downloading service, keep in mind to set the "Access-Control-Allow-Origin" header in the response.

The Java code section below can provide you with some ideas about it:

/**
 * Prepare to send the file.
 */
public static void prepareSendFile(HttpServletRequest request, HttpServletResponse response, String fileName,
                     String mimeType, boolean inline) throws UnsupportedEncodingException {
    String userAgent = getHeader(request, "user-agent").toLowerCase();
    fileName = decodeEntities(fileName);

    // Disable browser cache
    response.setHeader("Expires", "Sat, 6 May 1971 12:00:00 GMT");
    response.setHeader("Cache-Control", "must-revalidate");
    response.addHeader("Cache-Control", "no-store, no-cache, must-revalidate");
    response.addHeader("Cache-Control", "post-check=0, pre-check=0");
    response.setHeader("Pragma", "no-cache"); */

    // Allow to use files in different domains
    response.setHeader("Access-Control-Allow-Origin", "*");

    // Set MIME type
    response.setContentType(mimeType);

    if (userAgent.contains("msie") || userAgent.contains("trident")) {
        log.debug("Agent: Explorer ({})", request.getServerPort());
        fileName = URLEncoder.encode(fileName, "UTF-8").replaceAll("\\+", " ");

        if (request.getServerPort() == 443) {
            log.debug("HTTPS detected! Apply IE workaround...");
            response.setHeader("Cache-Control", "max-age=1");
            response.setHeader("Pragma", "public");
        }
    } else if (userAgent.contains("iphone") || userAgent.contains("ipad")) {
        log.debug("Agent: iPhone - iPad");
        // Do nothing
    } else if (userAgent.contains("android")) {
        log.debug("Agent: Android");
        fileName = URLEncoder.encode(fileName, "UTF-8").replaceAll("\\+", " ");
    } else if (userAgent.contains("mozilla")) {
        log.debug("Agent: Mozilla");
        fileName = MimeUtility.encodeText(fileName, "UTF-8", "B");
    } else {
        log.debug("Agent: Unknown");
    }

    if (inline) {
        response.setHeader("Content-disposition", "inline; filename=\"" + fileName + "\"");
    } else {
        response.setHeader("Content-disposition", "attachment; filename=\"" + fileName + "\"");
    }
}

/**
 * Get HTTP header.
 */
private static String getHeader(HttpServletRequest request, String name) {
    String value = request.getHeader(name);

    if (value != null) {
        return value;
    } else {
        return EMPTY_STRING;
    }
}

/**
 * decodeEntities
 */
private static String decodeEntities(String fileName) {
    String tmp = fileName.replaceAll("&", "&");
    tmp = tmp.replaceAll("&lt;", "<");
    tmp = tmp.replaceAll("&gt;", ">");
    tmp = tmp.replaceAll("&#34;", "\"");
    tmp = tmp.replaceAll("&#39;", "'");
    return tmp;
}