I strongly recommend you look at the names and descriptions of the forums before you post in them. So far all three posts have been in the wrong forums and have had to be moved. This one is no exception - you have posted in the forum which is meant for topics relating to the Sun Certified Java Developer assignment and exam. The topics in this forum are strictly J2SE, never J2EE.
If you were going to sit for the Sun Certified Business Component Developer exam, your question might fit in the EJB Certification (SCBCD) forum. If you were trying to understand something about BEA's WebLogic server your question might fit into the BEA/Weblogic forum. As it is, I have decided to move it to the Servlets forum. You can now find it here.