Spring Bean initialization and destruction of three ways (Spring Bean Life Cycle)

Spring container Bean is a life cycle, Bean's life cycle is created Bean ----> Initialize ----> destruction process, and allow the Spring Bean initialization is complete and perform a specific action before the destruction. The following three methods are commonly used to specify a particular operation:

1. After initializing the specified element init-method / destroy-method property / method calls before the destruction operation;
2. After initialization by implementing customized InitializingBean / DisposableBean Interface / destruction before the operation of the method;
3. Plus @PostConstruct or @PreDestroy comment on the specified method to develop this method is called before or destroyed after initialization, it is the use of InitDestroyAnnotationBeanPostProcessorpost-processors to achieve.
4. After using BeanPostProcessor-processor.

These types of configurations, the order of execution is what is it? We study examples below:

Bean Liezi categories: InitBeanAndDestroyBean.java

package com.chenfeng.xiaolyuh.entity;
 
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
 
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
 
public class InitBeanAndDestroyBean implements InitializingBean, DisposableBean {
	public String say() {
		return "Hello!" + this.getClass().getName();
	}
 
	public InitBeanAndDestroyBean() {
		System.out.println("执行InitBeanAndDestroyBean构造方法");
	}
 
	@Override
	public void destroy() throws Exception {
		System.out.println("接口-执行InitBeanAndDestroyBeanTest：destroy方法");
	}
 
	@Override
	public void afterPropertiesSet() throws Exception {
		System.out.println("接口-执行InitBeanAndDestroyBeanTest：afterPropertiesSet方法");
	}
 
	@PostConstruct
	public void postConstructstroy() {
		System.out.println("注解-执行InitBeanAndDestroyBeanTest：preDestroy方法");
	}
 
	@PreDestroy
	public void preDestroy() {
		System.out.println("注解--执行InitBeanAndDestroyBeanTest：preDestroy方法");
	}
 
	public void initMethod() {
		System.out.println("XML配置-执行InitBeanAndDestroyBeanTest：init-method方法");
	}
 
	public void destroyMethod() {
		System.out.println("XML配置-执行InitBeanAndDestroyBeanTest：destroy-method方法");
	}
}

Spring configuration class MyConfig.java

@Configuration // 声明成配置文件
@ComponentScan("com.chenfeng.xiaolyuh") // 扫描包
public class MyConfig {
	
	// 测试Bean的几种初始化和销毁方式，和执行顺序
	@Bean(initMethod="initMethod", destroyMethod="destroyMethod")
	public InitBeanAndDestroyBean initBeanAndDestroyBean() {
		return new InitBeanAndDestroyBean();
	}
}

Test class SpringIocTest.java

public class SpringIocTest {
    // 使用容器
    AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyConfig.class, CatEntity.class);
 
    @Test
    public void contextTest() {
    	// 测试Bean的三种初始化、销毁方式和执行顺序
    	System.out.println(context.getBean(InitBeanAndDestroyBean.class));
    }
    
    @After
    public void closeContext() {
    	context.close();
    }
 
}

Print Results:

执行InitBeanAndDestroyBean构造方法
20:46:58.845 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Found init method on class [com.xiaolyuh.init.destory.InitBeanAndDestroyBean]: public void com.xiaolyuh.init.destory.InitBeanAndDestroyBean.postConstructstroy()
20:46:58.846 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Found destroy method on class [com.xiaolyuh.init.destory.InitBeanAndDestroyBean]: public void com.xiaolyuh.init.destory.InitBeanAndDestroyBean.preDestroy()
20:46:58.846 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Registered init method on class [com.xiaolyuh.init.destory.InitBeanAndDestroyBean]: org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement@318a3b24
20:46:58.846 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Registered destroy method on class [com.xiaolyuh.init.destory.InitBeanAndDestroyBean]: org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement@a27dd7d7
20:46:58.847 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'initBeanAndDestroyBean' to allow for resolving potential circular references
后置处理器-执行：postProcessBeforeInitialization 方法 处理：initBeanAndDestroyBean
20:46:58.850 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Invoking init method on bean 'initBeanAndDestroyBean': public void com.xiaolyuh.init.destory.InitBeanAndDestroyBean.postConstructstroy()
注解-执行InitBeanAndDestroyBeanTest：preDestroy方法
20:46:58.850 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Invoking afterPropertiesSet() on bean with name 'initBeanAndDestroyBean'
接口-执行InitBeanAndDestroyBeanTest：afterPropertiesSet方法
20:46:58.851 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Invoking init method  'initMethod' on bean with name 'initBeanAndDestroyBean'
XML配置-执行InitBeanAndDestroyBeanTest：init-method方法
后置处理器-执行 执行：postProcessAfterInitialization 方法 处理：initBeanAndDestroyBean
20:46:58.851 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'initBeanAndDestroyBean'
20:46:58.851 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.context.event.internalEventListenerFactory'
20:46:58.883 [main] DEBUG org.springframework.context.annotation.AnnotationConfigApplicationContext - Unable to locate LifecycleProcessor with name 'lifecycleProcessor': using default [org.springframework.context.support.DefaultLifecycleProcessor@1838ccb8]
20:46:58.883 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'lifecycleProcessor'
20:46:58.885 [main] DEBUG org.springframework.core.env.PropertySourcesPropertyResolver - Could not find key 'spring.liveBeansView.mbeanDomain' in any property source


IOC容器完成初始化---->




打印 Spring 容器中的Bean  开始
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
myConfig
initBeanBeanPostProcessor
initBeanAndDestroyBean
打印 Spring 容器中的Bean  结束


20:46:58.990 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'initBeanAndDestroyBean'
com.xiaolyuh.init.destory.InitBeanAndDestroyBean@5ba88be8
20:46:58.991 [main] INFO org.springframework.context.annotation.AnnotationConfigApplicationContext - Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@5af97850: startup date [Mon Aug 26 20:46:58 CST 2019]; root of context hierarchy
20:46:58.991 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'lifecycleProcessor'
20:46:58.992 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@78691363: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory,myConfig,initBeanBeanPostProcessor,initBeanAndDestroyBean]; root of factory hierarchy
20:46:58.992 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Invoking destroy method on bean 'initBeanAndDestroyBean': public void com.xiaolyuh.init.destory.InitBeanAndDestroyBean.preDestroy()
注解--执行InitBeanAndDestroyBeanTest：preDestroy方法
20:46:58.992 [main] DEBUG org.springframework.beans.factory.support.DisposableBeanAdapter - Invoking destroy() on bean with name 'initBeanAndDestroyBean'
接口-执行InitBeanAndDestroyBeanTest：destroy方法
20:46:58.993 [main] DEBUG org.springframework.beans.factory.support.DisposableBeanAdapter - Invoking destroy method 'destroyMethod' on bean with name 'initBeanAndDestroyBean'
XML配置-执行InitBeanAndDestroyBeanTest：destroy-method方法


关闭IOC容器---->

It can be seen from the results of:

• Bean instantiation process: Constructor> BeanPostProcessor.postProcessBeforeInitialization ()> @PostConstruct> InitializingBean> init-method> BeanPostProcessor.postProcessAfterInitialization ()> vessel initialization completion
• Bean, during the destruction of: @PreDestroy> DisposableBean> destroy-method> destruction of container

If Bean is not a singleton, then Spring will not go to management Bean, Spring containers will only keep a Bean marked. Bean is created and initialized when the acquisition occurs Bean, Bean and destruction method is not called in again when the container is closed. Non-singleton situation, Bean destruction is to rely on GC.

Source

https://github.com/wyh-spring-ecosystem-student/spring-boot-student/tree/releases

spring-boot-student-spring 工程

layering-cache

Born to monitor multi-level caching framework layering-cache This is my open source to achieve a multi-level caching framework, if interested can look at