Question

Is it possible to access a context param from a jar in lib or from a normal java class?

Answer 1

You didn’t mention which framework you are using but assuming you are using HttpServlet you can use getServletContext method to retrieve the ServletContext and then you can retrieve context parameters by getInitParameter(String) method.

ServletContext ctx = getServletContext();
String dbDriver = ctx.getInitParameter( "your_parameter_name" );

You can read more about HttpServlet, ServletContext and getServletContext method.