I can write an ant script that copies updated class files to web-inf\\classes in tomcat. But how can I tell Tomcat 7.0 to auto pick up the changed class files f
Tomcat can only hot swap certain type of files such as JSP, and static files like JavaScript, CSS, etc. if you turn off cacheing but cannot hot swap Java classes, only restart the webapp. To achieve hot swapping Java classes, I’ve seen JRebel advertisement everywhere but have not tried their product.
However, you could preserve Tomcat session by commenting out a directive as explained in the Tomcat documentation site: http://tomcat.apache.org/tomcat-7.0-doc/config/manager.html#Disable_Session_Persistence.
Lastly, you could write ANT script to assemble WAR and redeploy every time the script is executed.
Example build.xml:
...
...
In any consolidation, I would avoid using Eclipse Tomcat Plugin for two reasons.