Separating war application name from war file name
Currently if i deploy a war file on tomcat named say myapp.war, I can access its url by http://localhost/myapp/MyServlet.
However what I want is to deploy a war with a version number in the war file name and still have the same url.
For eg, I want to deploy myapp-1.1.0.war and still have the url be http://localhost/myapp/MyServlet
Of course I need to keep updating the war and the version number will keep changing, so I cant hardcode the war filename anywhere.
Is there any setting in web.xml I can use to keep the same url for the app regardless of the war filename?
Answer
The solution is to stop using the automatic deployment feature of Tomcat, which takes the shortcut of setting the "context name" (the /myapp part of the URL) to the portion of the WAR filename before ".war".
Instead, extract the WAR contents to the filesystem yourself and setup an XML file at TOMCAT_HOME/conf/[enginename]/[hostname]/[contextname].xml which points the desired context path (such as /myapp) to the location of the application on disk (such as /opt/webapps/myapp-1.1.0/).
The Tomcat reference docs provide a good explanation of how Tomcat deploys applications automatically, and how you can configure customized logic for the mapping of context path to application file location (there are a handful of alternate ways to set this up other than the one I suggest above).