What are the benefits of IOC? What is the difference between singleton and prototype bean?

What are the benefits of IOC?

    ·   It minimizes the amount of code in your application.It makes your application easy to test as it doesn't require any singletons or JNDI lookup mechanisms in your unit test cases. Loose coupling is promoted with minimal effort and least intrusive mechanism.IOC containers support eager instantiation and lazy loading of services.

What is Spring IoC container?

The Spring IoC creates the objects, wire them together, configure them, and manage their complete lifecycle from creation till destruction. The Spring container uses dependency injection (DI) to manage the components that make up an application.

What are types of IoC containers? Explain them.

·   Bean Factory container: This is the simplest container providing basic support for DI .The BeanFactory is usually preferred where the resources are limited like mobile devices or applet based applications

·         Spring ApplicationContext Container: This container adds more enterprise-specific functionality such as the ability to resolve textual messages from a properties file and the ability to publish application events to interested event listeners.

What is the difference between singleton and prototype bean?

Prototype scope = A new object is created each time it is 

injected/looked up. It will use new SomeClass() each time.

Singleton scope = The same object is returned each time it 

is injected/looked up. Here it will instantiate one instance 

of SomeClass and then return it each time.