I have a question on J2SE and J2EE. I have listed my understanding of the difference between the two below, please let me know if I am correct.
J2EE is basically an extention of J2SE i.e. J2EE has more APIs than J2SE.
If I develop an application on J2SE...and I would need J2EE APIs, all I will have to do is add the J2EE APIs.
In other words developing on J2SE is entensible - one does not have to start with J2EE.
An example: I have an old application developed on J2SE. I want Web Services APIs, which is available as part of J2EE. All I have to do is download the J2EE classes and add them to the J2SE ones?
You are correct in terms of development and compiling your codes.
But J2EE applications requires an application server that offer runtime facilities for EJB,WebService,Servlets,JSP,... etc. You have to package your J2EE app in a JAR,WAR or EAR file and deploy it to the application server. The J2EE API from sun does does have a reference implementation, but it's not practical. Some of the more popular app servers are: WebLogic (BEA), WebSphere (IBM) and SunOne (SUN)