Interface to provide configuration for a web application. This is read-only while
the application is running, but may be reloaded if the implementation supports this.
This interface adds a getServletContext method to the generic ApplicationContext
interface, and defines a well-known application attribute name that the root
context must be bound to in the bootstrap process.
Like generic application contexts, web application contexts are hierarchical.
There is a single root context per application, while each servlet in the application
(including a dispatcher servlet in the MVC framework) has its own child context.
In addition to standard application context lifecycle capabilities,
WebApplicationContext implementations need to detect ServletContextAware
beans and invoke the setServletContext method accordingly.
public static
Note: If the startup of the root context fails, this attribute can contain an exception or error as value. Use WebApplicationContextUtils for convenient lookup of the root WebApplicationContext.