Question

I can set an environment variable with Eclipse when I click on the Tomcat Server and then Open Launch configuration -> Environment -> Variable, Value. What is no-gui, no-eclipse textual-xml equivalent of this variable setting?

Answer 1

Context Parameters

See: Context Parameters section of The Context Container page.

You can configure named values that will be made visible to the web application as servlet context initialization parameters by nesting <Parameter> elements inside this element. For example, you can create an initialization parameter like this:

<Context ...>
  ...
  <Parameter name="companyName" value="My Company, Incorporated"
         override="false"/>
  ...
</Context>

This is equivalent to the inclusion of the following element in the web application deployment descriptor (/WEB-INF/web.xml):

<context-param>
  <param-name>companyName</param-name>
  <param-value>My Company, Incorporated</param-value>
</context-param>

but does not require modification of the deployment descriptor to customize this value.