public static Map<String, String> mimeTypes() { if (MIME_TYPES == null) { MIME_TYPES = new HashMap<String, String>(); loadMimeTypes(MIME_TYPES, "META-INF/nanohttpd/default-mimetypes.properties"); loadMimeTypes(MIME_TYPES, "META-INF/nanohttpd/mimetypes.properties"); if (MIME_TYPES.isEmpty()) { LOG.log(Level.WARNING, "no mime types found in the classpath! please provide mimetypes.properties"); } } return MIME_TYPES; }