This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Prior to the advent of context listeners, a load-on-startup servlet was frequently used to perform application-wide initialization, but a context listener is a much better way to do it now that they are available.
It is guarenteed that all context listeners are executed before any servlets are loaded or executed.