java - JavaFX CSS URL isn't loading -

i trying load xml resource, , doing this:

fxmlloader = new fxmlloader(); root = fxmlloader.load(getclass().getresource("document.fxml").openstream()); 

when run code error:

null/../css/button.css javafx.fxml.loadexception:  unknown path:23 

when @ line 23 have this:

<url value="@../css/button.css" /> 

this works:

fxmlloader = new fxmlloader(); root = fxmlloader.load(getclass().getresource("document.fxml")); 

but when run following

controller = (documentcontroller)fxmlloader.getcontroller(); 

controller null

how can fix css issue?

this bit of guess, think issue you're providing input stream fxmlloader instead of url. because of this, fxmlloader unaware of location of fxml resource, , hence can't resolve .. in url tag. explain error message:

null/../css/button.css

javafx.fxml.loadexception:

unknown path:23

the path provided relative null because fxmlloader doesn't know location of fxml file; notice reports "unknown path" source of fxml.

try (which more common anyway)

fxmlloader = new fxmlloader(getclass().getresource("document.fxml")); root = fxmlloader.load();  

i'm figuring returns null controller because there error in loading fxml.