This doesn't really have anything to do with Java or Jalbum. Jalbum produces normal, plain-vanilla HTML. Including PHP snippets in it is the same as including PHP snippets in any HTML file, even one you created by hand.
Google for execute PHP in HTML, and you'll find a number of discussions about various ways of doing this. A couple of quick options:
First option: put a .php extension on the file, and include your PHP snippet like this:
<? include('mysnippet.php'); ?>
(more html stuff)
Second option: put a .shtml extension on the file, and include your PHP snippet like this:
...err, red-face time;~) Absolutely EVERYTHING like this I've
ALWAYS done on the server and pretty much always in PHP.
This 'ere Java/Jalbum thingummy is a new vector for me.
It's being done on a local workstation (w2k)... no interpreter.
More caffeine required and thanks for the wake up call;~)
----best wishes, Robert