I have another use case for deploying via context.xml:
I have a web app directory that I wish to load into the servlet engine multiple times with different context names/paths and parameters in context.xml. The META-INF approach does not work for this case (unless perhaps you select the option to deploy the directory, but generally I don't want to do that).
The reason behind this particular use case is a simple web app that is focused on a database instance. Exactly the same web app code, etc, can be used but each running app gets a different set of DBCP and JNDI parameters so as to target a different dataset.
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