Hi, currently URIProvider is not allowed to return null according to https://github.com/apache/sling-org-apache-sling-api/blob/333fa20f07a1d42897c9e0b6253bec5dcedb3e0b/src/main/java/org/apache/sling/api/resource/external/URIProvider.java#L48. This forces every URIProvider to throw an exception for the (pretty common) case it cannot provide a URI for a resource.
As creating exceptions comes with quite some overhead, I would propose to enhance that interface. As just allowing null return values would be backwards-incompatible I would propose to instead add a second method called "Optional<URI> getOptionalUriForResource(Resource, Scope, Operation)" with a default implementation which calls toUri and properly catches and logs IllegalArgumentExceptions. At the same time I would deprecate the existing method "toURI(...)". WDYT? Konrad
