2.spring bean生命周期

目录

image.png

1.bean的生命周期

创建->初始化->销毁

graph TB
a("容器启动")-->b("bean实例化")
b-->c("设置对象属性")
c-->d("检查Aware相关接口并设置相关依赖")
d-->e("BeanPostProcesser前置处理")
e-->f("InitializingBean调用#afterPropertiesSet")
f-->m("调用initMethod指定方法")
m-->g("InitializingBean调用#postProcessAfterInitialization")
g-->h("放置map中")
h-->i("DisposableBean#destroy")
i-->j("调用destroyMethod指定方法")
j-->en("结束")

1.@Bean initMethod和destroyMethod

指定该bean的初始化和销毁方法

2.实现接口InitializingBean，DisposableBean

3.JSR250

使用注解 @PostConstruct初始化操作 @PreDestroy销毁操作

4.BeanPostProcessor

1.代码

1.1 bean对象

public class MyInitBean implements InitializingBean, DisposableBean , BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("-------Before-BeanPostProcessor---"+bean+"     "+beanName);
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("-------After-BeanPostProcessor---"+bean+"     "+beanName);

        return bean;
    }
    private void init() {
        System.out.println(" -----指定方法 InitEntity3 initMethod start*****************");
    }

    private void end() {
        System.out.println("-----指定方法 InitEntity3 initMethod destroyMethod*****************");
    }

    public MyInitBean() {
        System.out.println("-----构造器");
    }

    @Override
    public void destroy() throws Exception {
        System.out.println("-----接口DisposableBean destroy");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("-----接口InitializingBean afterPropertiesSet");
    }

    @PostConstruct
    public void PostConstruct() {
        System.out.println("------ 注解@PostConstruct--");
    }

    @PreDestroy
    public void PreDestroy() {
        System.out.println("------ 注解@PreDestroy--");
    }


}

1.2 配置类

@Configuration
public class MyConfiguation {
    @Bean(initMethod = "init",destroyMethod = "end")
    public MyInitBean myInitBean() {
        return new MyInitBean();
    }
}

1.3 测试类

    public static void main(String[] args) {
        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MyConfiguation.class);
        System.out.println("_--------------------------------_");
        applicationContext.close();
        System.out.println("_--------------------------------_");
    }

1.4 结果

-----构造器
------ 注解@PostConstruct--
-----接口InitializingBean afterPropertiesSet
 -----指定方法 InitEntity3 initMethod start*****************
-------Before-BeanPostProcessor---org.springframework.context.event.EventListenerMethodProcessor@276438c9     org.springframework.context.event.internalEventListenerProcessor
-------After-BeanPostProcessor---org.springframework.context.event.EventListenerMethodProcessor@276438c9     org.springframework.context.event.internalEventListenerProcessor
-------Before-BeanPostProcessor---org.springframework.context.event.DefaultEventListenerFactory@33b37288     org.springframework.context.event.internalEventListenerFactory
-------After-BeanPostProcessor---org.springframework.context.event.DefaultEventListenerFactory@33b37288     org.springframework.context.event.internalEventListenerFactory
_--------------------------------_
------ 注解@PreDestroy--
-----接口DisposableBean destroy
-----指定方法 InitEntity3 initMethod destroyMethod*****************
_--------------------------------_