Todd David Rudick wrote JavaDict which is available at http://www.cs.arizona.edu/japan/JavaDict/index.html It requires JDK 1.1. I have got this to work under Linux with JDK 1.1.3 thanks to Todd Rudick's font.properties file that allows Japanese fonts to be displayed.
JavaDict is a good implementation of a dictionary using Java. It has a graphic interface, which may make it easier to use for novices than xjdic. An example of the lookup of kanji using the radical method is shown below.
JavaDict compares favorably to the proven standard for Japanese
English
dictionaries, xjdic, in one respect only, the lookup of kanji by
a novice. Although the graphic interface makes JavaDict more
aethetically pleasing, serious users of a dictionary would be better
off with xjdic due to the maturity of the program which makes it
more stable. JavaDict is a new program and is hampered by the
instability of the current release of JDK 1.1.3 for Linux.
Still,
this impressive program written in Java, does have a few advantages,
which might be particularly beneficial for a novice student of Japanese.

One thing that I have unable to do under JavaDict is to cut and paste Japanese into the Japanese to English dictionary. I'd be interested if someone manages to do this.