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

Answer 1

Scenario 1

In client application (application is not web application, e.g may be swing app)

private static ApplicationContext context = new  ClassPathXmlApplicationContext("test-client.xml");

context.getBean(name);

No need of web.xml. ApplicationContext as container for getting bean service. No need for web server container. In test-client.xml there can be Simple bean with no remoting, bean with remoting.

Conclusion: In Scenario 1 applicationContext and DispatcherServlet are not related.

Scenario 2

In a server application (application deployed in server e.g Tomcat). Accessed service via remoting from client program (e.g Swing app)

Define listener in web.xml

    org.springframework.web.context.ContextLoaderListener

At server startup ContextLoaderListener instantiates beans defined in applicationContext.xml.

Assuming you have defined the following in applicationContext.xml:

The beans are instantiated from all four configuration files test1.xml, test2.xml, test3.xml, test4.xml.

Conclusion: In Scenario 2 applicationContext and DispatcherServlet are not related.

Scenario 3

In a web application with spring MVC.

In web.xml define:

    springweb
    org.springframework.web.servlet.DispatcherServlet    



    springweb
    *.action

When Tomcat starts, beans defined in springweb-servlet.xml are instantiated. DispatcherServlet extends FrameworkServlet. In FrameworkServlet bean instantiation takes place for springweb . In our case springweb is FrameworkServlet.

Conclusion: In Scenario 3 applicationContext and DispatcherServlet are not related.

Scenario 4

In web application with spring MVC. springweb-servlet.xml for servlet and applicationContext.xml for accessing the business service within the server program or for accessing DB service in another server program.

In web.xml the following are defined:

    org.springframework.web.context.ContextLoaderListener



    springweb
    org.springframework.web.servlet.DispatcherServlet        



    springweb
    *.action

At server startup, ContextLoaderListener instantiates beans defined in applicationContext.xml; assuming you have declared herein:

The beans are all instantiated from all four test1.xml, test2.xml, test3.xml, test4.xml. After the completion of bean instantiation defined in applicationContext.xml, beans defined in springweb-servlet.xml are instantiated.

So the instantiation order is: the root (application context), then FrameworkServlet.

Now it should be clear why they are important in which scenario.