java - Difference between applicationContext.xml and spring-servlet.xml in Spring Framework

Question

• Are applicationContext.xml and spring-servlet.xml related anyhow in Spring Framework?
  
• Will the properties files declared in applicationContext.xml be available to DispatcherServlet?
  
• On a related note, why do I need a *-servlet.xml at all? Why is applicationContext.xml alone insufficient?

Answer 1

Spring lets you define multiple contexts in a parent-child hierarchy.

The applicationContext.xml defines the beans for the "root webapp context", i.e. the context associated with the webapp.

The spring-servlet.xml (or whatever else you call it) defines the beans for one servlet's app context. There can be many of these in a webapp, one per Spring servlet (e.g. spring1-servlet.xml for servlet spring1, spring2-servlet.xml for servlet spring2).

Beans in spring-servlet.xml can reference beans in applicationContext.xml, but not vice versa.

All Spring MVC controllers must go in the spring-servlet.xml context.

In most simple cases, the applicationContext.xml context is unnecessary. It is generally used to contain beans that are shared between all servlets in a webapp. If you only have one servlet, then there's not really much point, unless you have a specific use for it.