[ccp4bb] How to run Java program?

[yang li]

Hi,
  I have a java program named Switch.java, I want to run it under fedora5
core, I donnot know any compiler
I need to install? I installed a package named jre-1_5_0_11-
linux-i586-rpm.bin, when I use command
 java Switch.java
wrong information came out:
Exception in thread "main" java.lang.NoClassDefFoundError: SwitchI
  at gnu.java.lang.MainThread.run(libgcj.so.7)
Caused by: java.lang.ClassNotFoundException: SwitchI not found in
gnu.gcj.runtime.SystemClassLoader{urls=[file:./], parent=
gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}}
  at java.net.URLClassLoader.findClass(libgcj.so.7)
  at java.lang.ClassLoader.loadClass(libgcj.so.7)
  at java.lang.ClassLoader.loadClass(libgcj.so.7)
  at java.lang.Class.forName(libgcj.so.7)
  at gnu.java.lang.MainThread.run(libgcj.so.7)

Then I used command yum install libgcj.so.7 , but it was not helpful.
I am a java newhand, any help will be appreciated, thanks!