When do you use a JSP and when a Servlet? [duplicate]

Question

I have an application that sends the customer to another site to handle the payments. The other site, outside of the customer, calls a page on our server to let us know what the status is of the payment. The called page checks the parameters that are given by the payment application and checks to see whether the transaction is known to us. It then updates the database to reflect the status. This is all done without any interaction with the customer.

I have personally chosen to implement this functionality as a JSP since it is easier to just drop a file in the file system than to compile and package the file and then to add an entry into a configuration file.

Considering the functionality of the page I would presume that a servlet would be the preferred option. The question(s) are:

Is my presumption correct?

Is there a real reason to use a servlet over a JSP?

What are those reasons?

Answer 1

A JSP is compiled to a servlet the first time it is run. That means that there's no real runtime difference between them.

However, most have a tradition to use servlets for controllers and JSPs for views. Since controllers are just java classes you can get full tool support (code completion etc.) from all IDEs. That gives better quality and faster development times compared to JSPs. Some more advanced IDE's (IntelliJ IDEA springs to mind) have great JSP support, rendering that argument obsolete.

If you're making your own framework or just making it with simple JSPs, then you should feel free to continue to use JSPs. There's no performance difference and if you feel JSPs are easier to write, then by all means continue.