spring中bean的生命周期详解

本文主要介绍了spring中bean的生命周期.

下面是通过applicationContext获取bean的过程

首先，beans.xml文件配置

		
				siege
		

PersonService.java

package 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;
	}

}

最后,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:

https://img-my.csdn.net/uploads/201501/31/1422716140_4219.jpg