Java: What is Spring Bean lifecycle?

Bean lifecycle — the complete sequence of events from bean creation to destruction in the Spring IoC container.

Phases:

1. Instantiation — constructor called.
2. Populate properties — dependency injection.
3. BeanNameAware — set bean name.
4. BeanFactoryAware — set bean factory.
5. @PostConstruct — custom init.
6. InitializingBean.afterPropertiesSet() — after properties set.
7. Custom init-method — bean ready.
8. @PreDestroy — cleanup before destruction.

1@Component
2public class MyBean implements InitializingBean, DisposableBean {
3    @PostConstruct
4    public void init() {
5        System.out.println("Bean initialized");
6    }
7    @Override
8    public void afterPropertiesSet() {
9        System.out.println("Properties set");
10    }
11    @PreDestroy
12    public void cleanup() {
13        System.out.println("Bean destroyed");
14    }
15}

Scope impact: Singleton beans live for app lifetime; prototype beans are not managed after creation.