Spring Bean 生命周期测试

• Z时代
• 2024-01-10
• 分类：综合

本文内容纲要：

- 注册InstantiationAwareBeanPostProcessor接口。
- 输出
- 生命周期图解
- Spring 实现按 init-method 和destory-method的三种方式

本文代码GitHub地址

Bean的生命周期是开始创建到销毁的过程。需要实现相关的类BeanNameAware ，DisposableBean, InitializingBean ，并注册InstantiationAwareBeanPostProcessor。

Bean类实现BeanNameAware ，DisposableBean, InitializingBean 接口

package com.bean.life.entity;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.*;
import org.springframework.stereotype.Component;
@Component
public class User implements BeanFactoryAware
    , BeanNameAware
    , InitializingBean
    , DisposableBean
{
    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        System.out.println("BeanFactoryAware  setBeanFactory");
    }
    @Override
    public void setBeanName(String s) {
        System.out.println("BeanNameAware接口：  setBeanName = " + s);
    }
    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("InitializingBean接口：  afterPropertiesSet");
    }
    @Override
    public void destroy() throws Exception {
        System.out.println("DisposableBean接口：  destroy");
    }
    @PostConstruct
    public  void init(){
        System.out.println("PostConstruct");
    }
    @PreDestroy
    public  void destory(){
        System.out.println("PreDestroy");
    }
}

注册InstantiationAwareBeanPostProcessor接口。

这里的**InstantiationAwareBeanPostProcessorAdapter是 InstantiationAwareBeanPostProcessor 的子孙类。

package com.bean.life.entity;
import org.springframework.beans.BeansException;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter;
import org.springframework.stereotype.Component;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Constructor;
@Component
public class MyInstantiationAwareBeanPostProcessor extends
        InstantiationAwareBeanPostProcessorAdapter {
    public MyInstantiationAwareBeanPostProcessor() {
        super();
    }
    @Override
    public Constructor<?>[] determineCandidateConstructors(Class<?> beanClass, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口： determineCandidateConstructors: " + beanName);
        }
        return super.determineCandidateConstructors(beanClass, beanName);
    }
    @Override
    public Object getEarlyBeanReference(Object bean, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口： getEarlyBeanReference: " + beanName);
        }
        return super.getEarlyBeanReference(bean, beanName);
    }
    @Override
    public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口： postProcessBeforeInstantiation: " + beanName);
        }
        return super.postProcessBeforeInstantiation(beanClass, beanName);
    }
    @Override
    public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口： postProcessAfterInstantiation : " + beanName);
        }
        return super.postProcessAfterInstantiation(bean, beanName);
    }
    @Override
    public PropertyValues postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口：  postProcessPropertyValues: " + beanName);
        }
        return super.postProcessPropertyValues(pvs, pds, bean, beanName);
    }
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口： postProcessBeforeInitialization: " + beanName);
        }
        return super.postProcessBeforeInitialization(bean, beanName);
    }
    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        if(beanName.equals("user")){
            System.out.println("MyInstantiationAwareBeanPostProcessor接口：  postProcessAfterInitialization: " + beanName);
        }
        return super.postProcessAfterInitialization(bean, beanName);
    }
}

输出

MyBeanFactoryPostProcessor ---  BeanFactoryPostProcessor
MyInstantiationAwareBeanPostProcessor接口： postProcessBeforeInstantiation: user
MyInstantiationAwareBeanPostProcessor接口： determineCandidateConstructors: user
MyInstantiationAwareBeanPostProcessor接口： postProcessAfterInstantiation : user
MyInstantiationAwareBeanPostProcessor接口：  postProcessPropertyValues: user
BeanNameAware接口：  setBeanName = user
BeanFactoryAware  setBeanFactory
MyInstantiationAwareBeanPostProcessor接口： postProcessBeforeInitialization: user
PostConstruct
InitializingBean接口：  afterPropertiesSet
MyInstantiationAwareBeanPostProcessor接口：  postProcessAfterInitialization: user
PreDestroy
DisposableBean接口：  destroy

生命周期图解

Spring 实现按 init-method 和destory-method的三种方式

• 方式1：xml配置方式

  package com.bean.life.entity;

  public class User

  {

  public  void init(){
      System.out.println("PostConstruct");
  }
  public  void destory(){
      System.out.println("PreDestroy"); } }
  

• 方式2：注解配置

添加*@PostConstruct 和**@PreDestroy进行指定*

package com.bean.life.entity;
@Component
public class User
{
    @PostConstruct
    public  void init(){
        System.out.println("PostConstruct");
    }
    @PreDestroy
    public  void destory(){
        System.out.println("PreDestroy");
    }
}

• 方式3： 使用注解@Bean

  public @interface Bean {

  @AliasFor("name")

  String[] value() default {};

  @AliasFor("value")
  String[] name() default {};
  Autowire autowire() default Autowire.NO;
  String initMethod() default "";
  String destroyMethod() default "(inferred)";
  

  }

  @Configuration

  public class UserConfig{

    @Bean(initMethod="init",destoryMethod="destory")
    public User user(){
    return new User();
  }
  

  }

本文内容总结：注册InstantiationAwareBeanPostProcessor接口。，输出，生命周期图解，Spring 实现按 init-method 和destory-method的三种方式，

原文链接：https://www.cnblogs.com/lgjlife/p/10664320.html

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