深入理解Spring中bean的生命周期介绍

Z时代
2024-01-10
分类：IT

1.以ApplocationContext上下文单例模式装配bean为例，深入探讨生命周期" title="bean的生命周期">bean的生命周期：

（1）.生命周期图：

（2）.具体事例：

person类实现BeanNameAware,BeanFactoryAware接口


public class Person implements BeanNameAware ,BeanFactoryAware{
  private String name;
  public Person(){
    System.out.println("调用构造器为属性值初始化");
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  @Override
  public void setBeanName(String arg0) {
    // TODO Auto-generated method stub
    System.out.println("获取beanName id值"+" "+arg0);
  }
  @Override
  public void setBeanFactory(BeanFactory arg0) throws BeansException {
    // TODO Auto-generated method stub
    System.out.println("获取BeanFactory" +" "+arg0);
  }
}


public class MyBeanPostProcessor implements BeanPostProcessor{
  @Override
  public Object postProcessAfterInitialization(Object arg0, String arg1) throws BeansException {
    // TODO Auto-generated method stub
    System.out.println("调用postProcessAfterInitialization");
    return arg0;
  }
  @Override
  public Object postProcessBeforeInitialization(Object arg0, String arg1) throws BeansException {
    // TODO Auto-generated method stub
    System.out.println("调用postProcessBeforeInitialization");
    return arg0;
  }
}

ApplicationContext.xml配置文件:


<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- bean的配置文件 -->
<bean id="person" class="org.jingdong.bean.life.Person">
<property name="name" value="grl"></property>
</bean>
<bean id="myBeanPostProcessor" class="org.jingdong.bean.life.MyBeanPostProcessor"></bean>
</beans>

Main.java


public class Main {
  public static void main(String[] args) {
    // 创建IOC容器
    ApplicationContext ac = new ClassPathXmlApplicationContext("org/jingdong/bean/life/applicationContext.xml");
    //从容器中获取bean实例
    Person person = (Person) ac.getBean("person");
    //使用bean
    System.out.println(person.getName());
  }
}

2.以Spring Factory装配bean为例：

（1）.生命周期图：