If you intend to implement a WebApplicationContext that reads bean definitions
from configuration files, consider deriving from AbstractRefreshableWebApplicationContext,
reading the bean definitions in an implementation of the loadBeanDefinitions
Interprets resource paths as servlet context resources, i.e. as paths beneath
the web application root. Absolute paths, e.g. for files outside the web app root,
can be accessed via "file:" URLs, as implemented by AbstractApplicationContext.
In addition to the special beans detected by
this class detects a ThemeSource bean in the context, with the name "themeSource".
the corresponding Theme, or null if none defined.
Note that, by convention, a ThemeSource should at least be able to
return a default Theme for the default theme name "theme" but may also
return default Themes for other theme names.