This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
In a normal servlet container, there is only one instance of a servlet class for a particular web application. I suppose that could be called a "singleton." Learning how to program for the situation where any number of requests can "simultaneously" be processed by that one instance is the big jump you have to make from programming single user applications. Bill
Learning how to program for the situation where any number of requests can "simultaneously" be processed by that one instance is the big jump you have to make from programming single user applications.
I am not sure which is easier. Personally writing servlet is more obvious for me than programming standalone Swing application. I think that is because servlets do put a lot of constraints on programmer, while there is much freedom in single user applications. Freedom = thinking = reinventing wheels = time = -money
Originally posted by anandbhucs rai: Can we make "singelton servlet" ?
Yes you can, although a much more important questions is should you do it. No you definitely should not.
Servlet containers are required to manage Servlet instances internally, and there are a few different requirements it needs to meet. If you make a Servlet a Singleton it will prevent the Servlet container for working correctly.
Maybe you could explain why you want a singleton servlet - what is the requirement driving you towards a singleton servlet as a solution?
Apart from David O'Meara's point (you shouldn't try to force servlets to be singletons, or you may break the web container), singletons in general become difficult or impossible to manage if you decide to make your web application distributed.