For my High Schooler: Application Server

Yash: Today in Java class, we discussed Application Server.

Me: What is that?

Yash: Don’t make fun of me.  Can you correlate it to some interesting example?

Me: I can try.

Yash: hmm…

Me: Ok. Name the planet on which we live.

Yash: Obviously, Earth.

Me: Is whole of earth has a same geographic feature?

Yash: No. We have sea, savanna, tropical jungles, desert, glaciers, polar ice caps, etc.

Me: Good.  Are animals living in these geographies same or different?

Yash: Naturally different. In sea you will find shark, whales, octopus and other sea creatures, in jungles you can encounter lions, giraffe, elephants and other animals. You will certainly find polar bears at North Pole. Similarly in other geographies different animals are living.

Me: Very true. Why so?

Yash: Because, each animal has different requirements to live, this can be fulfilled in a particular geography.

Me: Excellent. Let me rephrase.  Each animal has a different life cycle which can be supported only in a particular geography. Also there are some common requirements like oxygen to breathe, water to hydrate, etc.  which are available in all geographies.

Yash: yep.

Me: Let’s put this whole concept in technical terms. Earth is an Application Server which provides some minimum set of features (like security, object pool, etc.) to hosted containers like tropical jungles, seas, savanna, etc. (Servlet container, JSP Container, EJB Container, JMS Provider, etc.). These hosted containers provide life cycle support to its residents like sharks, whales, lions, etc. (Servlets, JSPs, EJBs, etc.).

Yash: This is terrific.

Me: My pleasure. It’s time for dessert.