SISIS: fix regex for cover URL for Dresden Städtische Bibliotheken

[StefRe]

In Dresden, they changed the URL in the AJAX section: it now starts with "/webOPACClient/", which is also part of the opac_url.
OLD: "jsp/result..." (used for instance in Erfurt)
NEW: "/webOPACClient/jsp/result..." (used in Dresden)

So we retrieve just the part starting with "jsp/result..."

Eliminate duplicate definition of the regex in parse_search and loadDetail.

[johan12345]

The new kind "/webOPACClient/jsp/result..." seems to be a root-relative URL. Instead of solving this within the regex, I would rather suggest actually resolving the URL (so this is not dependent on the root path being called webOPACClient):

String path = matcher.group(1);
String url = new URI(opac_url + "/").resolve(path).toString();

Does this work?

[StefRe]

Yes, it works.
As URI methods may throw exceptions I refactored it into a separate method. This makes unit testing it much easier too.

[johan12345]

That looks good, thank you!