private String getMime(String extension) {
            String mime = "";
            switch (extension) {
                case ".pdf":
                    mime = "application/pdf";
                    break;
                case ".png":
                    mime = "image/png";
                case ".css":
                    mime = "text/css";
                    break;
                case ".js":
                    mime = "text/javascript";
                    break;
                case ".html":
                    mime = "text/html";
                    break;
                case ".jar":
                    mime = "application/java-archive";
                    break;
            }
            return mime;
        }