Hotfix Code in tomcat container running groovy application

Hi,

Current I m running my application on Java/J2ee/JSP using tomcat server. I would like to move to groovy grails application as
I heard groovy is dynamic, and we can do code change during runtime on tomcat container similar to JSP/GSPs. I tried alot to find the dynamic groovy code changes using MetaClass programming and ExpandoMetaClass, following are the references.

Reference URLs

Hot-fixing Code running inside Web Container with Groovy

http://stackoverflow.com/questions/1390243/hotfixing-code-running-inside-web-container-with-groovy

Modifying groovy code at run-time in grails application

http://stackoverflow.com/questions/2760735/modifying-groovy-code-at-runtime-in-grails-application

Embedding a Groovy Console in a Java Server Application

http://groovy.codehaus.org/Embedding+a+Groovy+Console+in+a+Java+Server+Application

Run-time vs Compile time, Static vs Dynamic

http://groovy.codehaus.org/Runtime+vs+Compile+time,+Static+vs+Dynamic

Compile Time and Run-time Meta-programming With Groovy

http://www.slideshare.net/openblend/open-blend-2010-groovy-metaprogramming-jeff-brown

Still no luck for me to get the hot-fix on tomcat container. Please help me in understanding how can I fix the code on tomcat without server restart.

-AMIT

Grails reloads modified classes while running the application in development mode. In production, this is turned off because it is not performant.

Thanks Gregg!!!

Following is my concern, I have built a development war and deployed it on external tomcat server and tried to change the groovy files, but I m not finding it under war exploded. If I change the files in the source directory how it reloads it? But for GSPs exists under webapps.

Your help will be appreciated. Thanks once again for quick response.

-AMIT

From the grails docs:

This target is not intended for deployment as the container in development mode is configured to auto-reload changes at runtime which has an overhead attached to it and will not scale well.

It's not because it's a development WAR but because the embedded container that Grails uses (Tomcat by default) is configured to auto-reload changes. So it is kind of a combination. But when you deploy to an external container, regardless of the environment you build the WAR for, it won't auto-reload. Also, when you build the WAR, you won't find groovy files. They get compiled to bytecode.