深入理解Spring中bean的生命周期
[Spring中bean的生命周期]
bean的生命周期
1.以ApplocationContext上下文单例模式装配bean为例,深入探讨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
1 public class Person implements BeanNameAware ,BeanFactoryAware{ 2 3 private String name; 4 5 public Person(){ 6 System.out.println("调用构造器为属性值初始化"); 7 } 8 9 public String getName() { 10 return name; 11 } 12 13 public void setName(String name) { 14 this.name = name; 15 } 16 17 @Override 18 public void setBeanName(String arg0) { 19 // TODO Auto-generated method stub 20 System.out.println("获取beanName id值"+" "+arg0); 21 22 } 23 24 @Override 25 public void setBeanFactory(BeanFactory arg0) throws BeansException { 26 // TODO Auto-generated method stub 27 System.out.println("获取BeanFactory" +" "+arg0); 28 29 } 30 31 32 }
1 public class MyBeanPostProcessor implements BeanPostProcessor{ 2 3 @Override 4 public Object postProcessAfterInitialization(Object arg0, String arg1) throws BeansException { 5 // TODO Auto-generated method stub 6 System.out.println("调用postProcessAfterInitialization"); 7 return arg0; 8 } 9 10 @Override 11 public Object postProcessBeforeInitialization(Object arg0, String arg1) throws BeansException { 12 // TODO Auto-generated method stub 13 System.out.println("调用postProcessBeforeInitialization"); 14 return arg0; 15 } 16 17 }
ApplicationContext.xml配置文件:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> 5 <!-- bean的配置文件 --> 6 <bean id="person" class="org.jingdong.bean.life.Person"> 7 <property name="name" value="grl"></property> 8 </bean> 9 10 <bean id="myBeanPostProcessor" class="org.jingdong.bean.life.MyBeanPostProcessor"></bean> 11 </beans>
Main.java
1 public class Main { 2 public static void main(String[] args) { 3 // 创建IOC容器 4 ApplicationContext ac = new ClassPathXmlApplicationContext("org/jingdong/bean/life/applicationContext.xml"); 5 //从容器中获取bean实例 6 Person person = (Person) ac.getBean("person"); 7 //使用bean 8 System.out.println(person.getName()); 9 } 10 }
2.以Spring Factory装配bean为例:
(1).生命周期图: