bug#24327: java does not support swing

[Alex Vong]

Hi,

Our current java does not support swing. To reproduce, first install
java and clojure. Then start the clojure repl by running:
  $ ~/.guix-profile/bin/java -cp ~/.guix-profile/share/java/clojure-1.8.0.jar 
clojure.main

Then try the repl by typing:
  => (+ 1 2 3)
  6

Now run:
  => (javax.swing.JOptionPane/showMessageDialog nil "Hello World")
  NullPointerException   sun.awt.FontConfiguration.getVersion 
(FontConfiguration.java:1264)

Note that the above test case is taken from
<https://clojure.org/guides/getting_started>.

In contrast, if we replace ~/.guix-profile/bin/java by /usr/bin/java in
the command, we do not get a nullpointerexception (my base distro is
debian testing). So there should be a problem in our java build. Any
ideas? 

Thanks,
Alex