If I deploy a war file to Tomcat, called for example foo-bar-1.1.2.war, how can I deploy it so that it is extracted to webapps/bar
Tomcat will always extract the contents of a war file, to a folder of the same name (when it's configured to deploy wars - as default etc.).
You can extract it to a folder name of your choice. So if you unzip the contents of foo.war to a folder called bar/ manually, instead of just dropping the war into the web apps folder, it'll still load the web application.
However, this is totally unnecessary as you can specify the URL pattern of the application without messing with the folder / war file name at all by overriding the context root element for your application:
This is often set in the Tomcat server.xml - but that practice is fairly widely discouraged. Instead, I'd suggest you use context.xml in the META-INF folder of your web application / war file:
When the application is deployed, the context.xml should be copied to /conf/Catalina/localhost but renamed to foo.xml
Note that conext roots must be unique and there are some additional considerations if you're using the autoDeploy or deployOnStartup operations (Source http://tomcat.apache.org/tomcat-7.0-doc/config/context.html).
Other options include:
foo-1.1.0 war in.foo/version1You could also use Ant (or an equivalent tool) to automate your deployments (and perform any of the above).