I want to initialize a global instance of a class before my Tomcat server completes startup and begins to offer my servlets. If this service somehow fails initialization, I'd like the entire startup sequence to fail as well (or as close to this as possible; it would be pointless for the server to be running otherwise). What's the best way I can accomplish this?
I want to initialize a global instance of a class before my Tomcat server completes startup and begins to offer my servlets. If this service somehow fails initialization, I'd like the entire startup sequence to fail as well (or as close to this as possible; it would be pointless for the server to be running otherwise). What's the best way I can accomplish this?
Share Improve this question edited Oct 23, 2015 at 6:50 jruizaranguren 13.6k7 gold badges58 silver badges74 bronze badges asked Sep 9, 2010 at 20:25 NBJackNBJack 3154 silver badges13 bronze badges2 Answers
Reset to default 19Each web application has a ServletContext associated with it. The ServletContext object is created when the application is started and is destroyed when the application is shut down. A ServletContext has a global scope and is similar to a global variable in an application.
http://www.javabeat.net/tips/178-servletcontextlistener-example.html
complete explanation here
http://onjava.com/pub/a/onjava/2001/04/12/listeners.html
One thing you can do portably is to implement a servlet that initializes everything you need in its init() method (and maybe call System.exit() if it fails, i do not know if you have permission to do this in Tomcat). Then you would load it using <load-on-startup> in your web.xml to specify initialization order.