spring生命周期-BeanPostProcessor在spring中应用

BeanPostProcessor 接口在spring中的实现类比较多，挑选几个比较重要的了解下

1.ApplicationContextAwareProcessor

可以通过实现ApplicationContextAware 接口，给bean里面注入applicationContext ；

@Component
public class Dog implements ApplicationContextAware {
    private ApplicationContext applicationContext ;

    public Dog(){
        System.out.println("dog constructor...");
    }

    //对象创建并赋值之后调用
    @PostConstruct
    public void init(){
        System.out.println("Dog....@PostConstruct...");
    }

    //容器移除对象之前
    @PreDestroy
    public void detory(){
        System.out.println("Dog....@PreDestroy...");
    }


    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
}

实现逻辑在

2.InitDestroyAnnotationBeanPostProcessor

此后置处理器主要是处理@PostConstruct和@PreDestroy相关注解的，打上断点，查看堆栈