public ActionForward download(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        if (logger.isDebugEnabled()) {
            logger.debug("entering 'AttachmentAction.download()' method...");
        }
        ActionMessages messages = new ActionMessages();

        String id = request.getParameter("id");
        String attachmentFile=request.getParameter("file");
        String type = request.getParameter("type");
        if (id != null||attachmentFile!=null) {
            Attachment attachment =null;
            if(id!=null) {
                attachment= mgr.view(id);
            } elseta.x

------解决方案--------------------
SmartUpLoad就可以了

或者cos