lifecycle

Lifecycle in Spring

Load bean definitions

Bean Definitions Loaded

• The @Configuration classes are processed

  • And/or @Components are scanned for
  • And/or XML files are parsed

• Bean definitions added to BeanFactory

  • Each indexed under its id

Post Process Bean Definitions

• Special BeanFactoryPostProcessor beans invoked

  • Can modify the definition of any bean

• Applies transformations to bean definitions

  • Before objects are actually created

• Several useful implementations provided in Spring

  • You can write your own (not common)
  • Implement BeanFactoryPostProcessor interface

Initialize bean instances (Instantiate Beans, Setters Called)

• Each bean is eagerly instantiated by default

  • Created in right order with its dependencies injected

• After dependency injection each bean goes through a post-processing phase

  • Further configuration and initialization may occur

• After post processing the bean is fully initialized and ready for use

  • Tracked by its id until the context is destroyed

• Set Bean Name: If the bean implements BeanNameAware interface, spring passes the bean’s id to setBeanName() method.

• Set Bean factory: If Bean implements BeanFactoryAware interface, spring passes the beanfactory to setBeanFactory() method.

Bean Post Processing

BeanPostProcessor -> InitializingBean -> BeanPostProcessor

• Pre Initialization: Also called post process of bean. If there are any bean BeanPostProcessor associated with the bean, Spring calls postProcesserBeforeInitialization() method.
• Initialize beans: If the bean implements InitializingBean,its afterPropertySet() method is called. If the bean has init method declaration, the specified initialization method is called.
• Post Initialization: – If there are any BeanPostProcessors associated with the bean, their postProcessAfterInitialization() methods will be called.

Bean ready for use

Now the bean is ready to use by the application, 99,99% application in here!

Destruction

• If the bean implements DisposableBean , it will call the destroy() method
• Or use @PreDestroy