KeyEvent.getKeyChar() doesn't return a correct unicode character
other than ascii.
For example, when a half-size katakana is inputted with Japanese keyborad,
No key event is sent on solaris and two key event are sent on windows95.
On windows95, the first key event has a hi-byte of Shift-JIS character
encoding as unicode character and the second key event has a low-byte of
Shift-JIS character encoding as unicode character.