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为什么总是一个生命当做一个重点？
Servlet –> servlet生命周期
Java对象生命周期
往往笔试，面试总喜欢问生命周期的问题？
① 实例化（当我们的程序加载beans.xml文件时）把我们的bean（前提是单态的即scope=singleton）实例化到内存
② 调用set方法设置属性
③ 如果你实现了bean名字关注接口（BeanNameAware）则，可以通过setBeanName获取id号
④ 如果你实现了bean工厂关注接口，则（BeanFactoryAware）则可以获取bean工厂，beanFactory
⑤ 如果你实现了ApplicationContextAware接口，则调用方法
public void setApplicationContext(ApplicationContext arg0)
throws BeansException {
// TODO Auto-generated method stub
System.out.println("setApplicationContext"+arg0);
}
⑥ 如果bean和一个后置处理器关联了，则会自动去调用Object postProcessBeforeInitialization方法
⑦ 了InitializingBean接口，则会调用afterPropertiesSet方法
⑧ 如果自己在<bean init-method=”init”>则可以在bean中定义自己的初始化方法
⑨ 如果bean和一个后置处理器关联了，则会自动去调用Object postProcessAfterInitialization方法
⑩ 使用我们的bean
? 容器关闭
? 可以通过实现DisposableBean接口来调用方法destroy
? 可以在<bean destroy-method=”fun1” /> 调用定制的销毁方法
小结：
我们在实际开发中往往没有用到这么多的过程，常见的过程是
1--2--6-10-9-11
问题：通过BeanFactory来获取bean对象，bean的生命周期是否和Applicationcontext 是一样吗?
不是一样，bean在工厂中创建的生命周期会简单一些
具体
项目结构
beans.xml
<?xml version="1.0" encoding="utf-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"> <bean id="personService" destroy-method="mydestroy" init-method="init" class="com.litao.beanlife.PersonService"> <!-- -这里注入我们属性，前提就是有setName才能OK --> <property name="name"> <value>xiaoming</value> </property> </bean> <bean id="personService2" class="com.litao.beanlife.PersonService"> <!-- -这里注入我们属性，前提就是有setName才能OK --> <property name="name"> <value>xiaohong</value> </property> </bean> <!-- 配置我们自己的后置处理器（有点类似我们的fiter） --> <bean id="myBeanPostProcessor" class="com.litao.beanlife.MyBeanPostProcessor" /> </beans>
App1.java
package com.litao.beanlife;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.core.io.ClassPathResource;
public class App1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/beanlife/beans.xml");
//BeanFactory factory = new XmlBeanFactory(new ClassPathResource("com/litao/beanlife/beans.xml"));
PersonService ps = (PersonService)ac.getBean("personService");
//PersonService ps = (PersonService)factory.getBean("personService");
ps.sayHi();
}
}
MyBeanPostProcessor.java
package com.litao.beanlife;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
public class MyBeanPostProcessor implements BeanPostProcessor {
//arg0就是beans.xml中要被实例的bean对象
public Object postProcessAfterInitialization(Object arg0, String arg1)
throws BeansException {
// TODO Auto-generated method stub
System.out.println("postProcessAfterInitialization函数被调用");
System.out.println(arg0+" 被创建的时间是"+new java.util.Date());
return arg0;
}
@Override
public Object postProcessBeforeInitialization(Object arg0, String arg1)
throws BeansException {
// TODO Auto-generated method stub
System.out.println("postProcessBeforeInitialization函数被调用");
return arg0;
}
}
PersonService.java
package com.litao.beanlife;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
public class PersonService implements BeanNameAware,BeanFactoryAware,ApplicationContextAware,InitializingBean{
private String name;
public PersonService(){
System.out.println("PersonService构造函数被调用");
}
public PersonService(String abc){
System.out.println("PersonService构造函数被调用");
}
public String getName() {
return name;
}
public void setName(String name) {
System.out.println("setName（String name）函数被调用");
this.name = name;
}
public void sayHi(){
System.out.println("hi "+ name);
}
//该方法可以给arg0传送正在被实例化的bean的id是什么
public void setBeanName(String arg0) {
// TODO Auto-generated method stub
System.out.println("setBeanName被调用 值为"+arg0);
}
//该方法可以传递beanFactory
public void setBeanFactory(BeanFactory arg0) throws BeansException {
// TODO Auto-generated method stub
System.out.println("setBeanFactory "+arg0);
}
//该方法传递上下文ApplicationContext
public void setApplicationContext(ApplicationContext arg0)
throws BeansException {
// TODO Auto-generated method stub
System.out.println("setApplicationContext"+arg0);
}
public void init(){
System.out.println("我自己的init方法");
}
@Override
public void afterPropertiesSet() throws Exception {
// TODO Auto-generated method stub
System.out.println("afterPropertiesSet()");
}
//定制我们的销毁方法
public void mydestroy() {
// TODO Auto-generated method stub
//我们可以关闭数据连接，socket，文件流，释放该bean的资源
System.out.println("释放各种资源");
}
}
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原文地址：http://www.cnblogs.com/litao0505/p/5777492.html
