I highly doubt that Maemo 5 would have default java support going by the history...

kasunh on Aug 27, 2009 | parent | context | favorite | on: Maemo 5 and Nokia n900 press release

I highly doubt that Maemo 5 would have default java support going by the history of Maemo.

But have a look at jalimo, https://wiki.evolvis.org/jalimo/index.php/Main_Page. You may be able to get something working. That is the beauty of openness.