availability to know, that resource url in embedded returns 404error

How can i know, that resource url in embedded component is available? Not only in my domain, but in others too.
Thanks

Don’t really know, but I would say, that as Embedded of Type BROWSER just renders into an iFrame you cannot make sure that the URL is actually available. Only thing you could do is trying to connect to the URL via URL#getConnection() and check for a 404 yourself. Other solution might be some type of HTTP-client-library.