Set Context Parameters
A context-param element defines a configuration parameter that is available to all servlets and filters within the context. Each context-param element contains a param-name element and a param-value element. For example, the element below defines a message parameter accessible to every servlet and filter in the context.
<param-value>25% off all hats!</param-value>
Each parameter in the context must have a distinct name. If the context contains more than one context‑param with the same param-name, the container will present one param‑value and ignore the others.