Chinese fonts showes wrong on program based on openjdk

[sailershen]

In my ubuntu 9.04, I installed a program named "ganttproject-2.0.9", it based on openjdk, in this program, the language is chinese, but the chinese font looks unfriendly, how to change it?

http://forum.ubuntu.org.cn/download/file.php?id=74959&mode=view/Screenshot111.jpeg