Making a Spring bean Applicationcontext aware

Suppose we have a webapplication with spring,

and we are initializing spring’s WebApplicationContext by configuring ContextLoaderListener in web.xml.

How can we get an instance of spring’s applicationContext object?

Possible solutions:

While configuring spring through web.xml the spring ApplicationContext object is set in the ServletContext.

To get ApplicationContext we say

So we can get spring ApplicationContext only where ServletContext is avaliable i.e. in Servlet,ServletFilter or any implementation class of ServletContextListener.

What if we dont want to write a servletFilter or ServletContextListener .

What if we need to access a spring bean before a servletFilter or servlet is called(for authentication)and we dont want to write a ServletContextListener.

How can we obtain spring’s applicationContext in this case?

One way to achieve this would be to use the ApplicationContextAware interface provided by Spring.

Create a class which implements ApplicationContextAware. The method, “setApplicationContext(…)” gets called during the creation of this bean, providing the reference to the context. Our program should store this for a later interaction with the context.

Initialize the new bean in applicationContext.xml

Now we can call the static method, ApplicationContextProvider.getApplicationContext(), from any class in our application, to get assess to the Spring ApplicationContext.

http://blog.imaginea.com/making-a-spring-bean-applicationcontext-aware/