Java Source World: What does a bean definition contain

What does a bean definition contain

The bean definition contains the information called configuration metadata which is needed for the container to know the following:

• How to create a bean
• Bean's life cycle details
• Bean's dependencies

Following is sequence of a bean life cycle in Spring :

Instantiate - First the spring container finds the bean's definition from the XML file and instantiates the

bean..

Populate properties - Using the dependency injection, spring populates all of the properties as specified in the bean definition..

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.

Pre Initialization - Also called postprocess of bean. If there are any bean Bean PostProcessors associated with the bean, Spring calls postProcesserBeforeInitialization() method.

Initialize beans - If the bean implements Intializing Bean,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.

Ready to use - Now the bean is ready to use by the application.

Destroy - If the bean implements DisposableBean, it will call the destroy() method .

Read: What are Spring beans