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ApplicationContext and WebApplicationContext

In non-Web Applications, ApplicationContext  is a Interface to provide bean configurations to our applications from XML files.  ApplicationContext has two Implementations which are
          1. FileSystemXmlApplicationContext
          2. ClassPathXmlApplicationContext


FileSystemXmlApplicationContext can access all your system files.It requires absolute path of your file.
e.g.
ApplicationContext ctx = new FileSystemXmlApplicationContext("c:/bean.xml");


ClassPathXmlApplicationContext can access all files placed in CLASSPATH or in .jar.It requires its file name only  to access.
e.g.
ApplicationContext ctx = new ClassPathXmlApplicationContext("bean.xml");


Then what is to do when application in Web Application?
 

All application having web.xml are Web Application.No Sceptice about it or have?
WebApplication has two hierarchies
         1. Root Context
         2. Each Servlet Spacific Contexct
 

Each servlet has its own application contexts with mappings,handlers,namespace....
But Root context is loaded by ContextLoaderListner and it is shared by all other specific contexts.You can say like a global.If want to declare global param,then declare them in root context and automatically will available in other contexts.
Both context are represented by WebApplicationContext interface.
Of course, WebApplicationContext extends ApplicationContext (extends in functionality not programming extend ) with extra feature that are required for Web-Application.


How you can get that context?
 

ApplicationContext and BeaFactoty are available in web application. BeanFactory has scope limited to beans and having functionality related to beans. ApplicationContext has functionality of beans as well as other functionalities present in servlet respective to bean.
BeanFactory is subset of ApplicationContext.
Same is the case applicable for ApplicationContextAwar  interface and BeanFactoryAware interface  which are required to get respective context.

WebApplicationContextUtils is available in spring web application to get web application context.


Sources:
http://docs.spring.io/spring/docs/2.5.x/api/org/springframework/context/ApplicationContext.html
http://docs.spring.io/spring/docs/2.0.x/api/org/springframework/web/context/WebApplicationContext.html
http://docs.spring.io/spring/docs/2.5.6/api/org/springframework/beans/factory/BeanFactoryAware.html
http://docs.spring.io/spring/docs/2.5.6/api/org/springframework/context/ApplicationContextAware.html

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