spring中bean的生命周期详解

spring中bean的生命周期详解

首先，beans.xml文件配置

<?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:context="http://www.springframework.org/schema/context"        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/context http://www.springframework.org/schema/context/spring-context-2.5.xsd                http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"><bean id="personService" class="com.beanlife.PersonService" init-method="init"  destroy-method="destoryBean">        <property name="name" >                <value>siege</value>        </property></bean><bean id="myBeanPostProcessor"  class="com.beanlife.MyBeanPostProcessor"></bean></beans>

PersonService.javapackage com.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,DisposableBean{    public PersonService() {        super();        System.out.println("PersonService被创建");    }    private String name;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;        System.out.println("setName被调用");    }    public void showName(){        System.out.println(this.name);    }    @Override    public void setApplicationContext(ApplicationContext appliactionContext)throws BeansException {        System.out.println(appliactionContext);    }    @Override    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {        System.out.println(beanFactory);    }    @Override    public void setBeanName(String  beanName) {        System.out.println(beanName);    }    @Override    public void afterPropertiesSet() throws Exception {        System.out.println("调用afterPropertiesSet()方法");    }    public void init(){        System.out.println("init方法被调用");    }    public void destoryBean(){        System.out.println("destoryBean方法被调用");    }    @Override    public void destroy() throws Exception {        System.out.println("destroy");    }}

继承BeanPostProcessor实现后置处理器的MyBeanPostProcessor.java

package com.beanlife;import org.springframework.beans.BeansException;import org.springframework.beans.factory.config.BeanPostProcessor;public class MyBeanPostProcessor implements BeanPostProcessor {    @Override    public Object postProcessAfterInitialization(Object arg0, String arg1)throws BeansException {        System.out.println("*********postProcessAfterInitialization**************");        System.out.println(arg0);        System.out.println(arg1);        System.out.println("*********postProcessAfterInitialization**************");        return arg0;    }    @Override    public Object postProcessBeforeInitialization(Object arg0, String arg1)throws BeansException {        System.out.println("*********postProcessBeforeInitialization**************");        System.out.println(arg0);        System.out.println(arg1);        System.out.println("*********postProcessBeforeInitialization**************");        return arg0;    }}

测试类Test.java

package com.beanlife;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {    public static void main(String[] args) {        ApplicationContext ac=new ClassPathXmlApplicationContext("com/beanlife/beans.xml");        PersonService p=(PersonService) ac.getBean("personService");        p.showName();    }}

测试结果如下:

PersonService被创建  setName被调用  personService  org.springframework.beans.factory.support.DefaultListableBeanFactory@a068d1: defining beans [personService,myBeanPostProcessor]; root of factory hierarchy  org.springframework.context.support.ClassPathXmlApplicationContext@75222b: display name [org.springframework.context.support.ClassPathXmlApplicationContext@75222b]; startup date [Sat Jan 31 21:36:08 CST 2015]; root of context hierarchy  *********postProcessBeforeInitialization**************  com.beanlife.PersonService@4f701  personService  *********postProcessBeforeInitialization**************  调用afterPropertiesSet()方法  init方法被调用  *********postProcessAfterInitialization**************  com.beanlife.PersonService@4f701  personService  *********postProcessAfterInitialization**************  siege  

若通过beanFactory获取bean,即修改Test.java文件为:

BeanFactory factory=new XmlBeanFactory(new ClassPathResource("com/beanlife/beans.xml"));PersonService p=(PersonService) factory.getBean("personService");

则测试结果为:

PersonService被创建  setName被调用  personService  org.springframework.beans.factory.xml.XmlBeanFactory@11274d2: defining beans [personService,myBeanPostProcessor]; root of factory hierarchy  调用afterPropertiesSet()方法  init方法被调用  siege  

整个bean的生命周期如下图: