spring生命周期
[MyBeanFactoryPostProcessor] constructor
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MyBeanFactoryPostProcessor] postProcessBeanFactory
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[MyBeanPostProcessor] constructor
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[MyInstantiationAwareBeanPostProcessor] constructor
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16:18:06.149 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'myBean'
**MyBean** construct.
16:18:06.154 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Found init method on class [com.example.LifeCycle.MyBean]: public void com.example.LifeCycle.MyBean.springPostConstruct()
16:18:06.154 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Found destroy method on class [com.example.LifeCycle.MyBean]: public void com.example.LifeCycle.MyBean.springPreDestroy()
16:18:06.154 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Registered init method on class [com.example.LifeCycle.MyBean]: org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement@21a44a0a
16:18:06.154 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Registered destroy method on class [com.example.LifeCycle.MyBean]: org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement@5caf49c4
16:18:06.176 [main] DEBUG org.springframework.beans.factory.annotation.InjectionMetadata - Registered injected element on class [com.example.LifeCycle.MyBean]: AutowiredMethodElement for public void com.example.LifeCycle.MyBean.setDescription(java.lang.String)
16:18:06.176 [main] DEBUG org.springframework.beans.factory.annotation.InjectionMetadata - Registered injected element on class [com.example.LifeCycle.MyBean]: AutowiredMethodElement for public void com.example.LifeCycle.MyBean.setName(java.lang.String)
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[MyInstantiationAwareBeanPostProcessor] postProcessAfterInstantiation
[MyInstantiationAwareBeanPostProcessor] postProcessPropertyValues
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[MyInstantiationAwareBeanPostProcessor] postProcessAfterInstantiation
[MyInstantiationAwareBeanPostProcessor] postProcessPropertyValues
16:18:06.177 [main] DEBUG org.springframework.beans.factory.annotation.InjectionMetadata - Processing injected element of bean 'myBean': AutowiredMethodElement for public void com.example.LifeCycle.MyBean.setDescription(java.lang.String)
16:18:06.177 [main] DEBUG org.springframework.beans.factory.annotation.InjectionMetadata - Processing injected element of bean 'myBean': AutowiredMethodElement for public void com.example.LifeCycle.MyBean.setName(java.lang.String)
*MyBean** setName
**MyBean** setDescription
**MyBean** BeanNameAware.getBeanName: myBean
**MyBean** BeanClassLoaderAware.setBeanClassLoader: class sun.misc.Launcher$AppClassLoader
**MyBean** BeanFactoryAware.setBeanFactory: class org.springframework.beans.factory.support.DefaultListableBeanFactory
**MyBean** ApplicationContextAware.setApplicationContext
[MyBeanPostProcessor] postProcessBeforeInitialization: class com.example.LifeCycle.MyBean: myBean
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**MyBean** init-method
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MyBean{name='Gigi', description='description'}
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**MyBean** @PreDestroy
**MyBean** DisposableBean.destroy
**MyBean** destory-method
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一些建议
不建议使用InitializingBean, DisposableBean，因为这个会增加代码与Spring框架的耦合性。
@PostConstruct，@PreDestroy是JavaX的标准，而非Java，Spring定义的注解，使用时应该注意。
将Bean从Spring IoC中移除之前需要释放持有的资源，建议在destroy-method中写释放资源的代码。
应用
了解Bean的生命周期有利于我们根据业务需要对Bean进行相关的拓展工作。
举个例子，在Bean初始化前希望用户名和密码。倘若将这些信息硬编码到工厂代码中显然是不安全的，一般地，公司会有一个统一的密码存储服务，通过调用开放的API获取用户名和密码。此时，我们可以在Bean的init-method中加入这样的逻辑：调用公司的密码存储服务API获取用户名和密码，加载至Bean的相关字段中。
再举个例子，在Bean被销毁之前，释放Bean与数据库的连接，那么我们可以把释放数据库连接这段逻辑放到destroy-method中。
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原文链接：https://blog.csdn.net/programmer_at/article/details/82533396
