Hi. I know it.
I installed complete JDK.
1/ download JDK from SUN (Now, version of Java is 1.4.2_10).
2/ Choose file *rpm.bin to install for FC.
3/ perform this command # ./j2sdk-1.4.2_10-Linux[...].bin
4/ I have file *.rpm
5/ install *.rpm with command #rpm -ivh j2sdk[...].rpm
6/ make CLASSPATH variable.
7/ test with simple code.
it is very easy