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IOC初始化和互相引用解决

观察IOC中容器初始化某个Bean顺序，现先一个JAVABean类，看看控制台输出：package com.google.aop.exception.ioc;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

public class JAVABean implements InitializingBean, DisposableBean,
        BeanFactoryAware, BeanPostProcessor, BeanFactoryPostProcessor {
    // private MyBean myBean;
    //
    // public MyBean getMyBean() {
    // return myBean;
    // }
    //
    // public void setMyBean(MyBean myBean) {
    // System.out.println("JAVABean 中初始化 属性myBean");
    // this.myBean = myBean;
    // }

    public JAVABean() {
        System.out.println("JAVABean 初始化成功");
    }

    public void init() {
        System.out.println("JAVABean init");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("JAVABean afterPropertiesSet");

    }

    @Override
    public void destroy() throws Exception {
        System.out.println("JAVABean destroy");

    }

    @Override
    public void setBeanFactory(BeanFactory arg0) throws BeansException {
        System.out.println("JAVABean setBeanFactory");

    }

    @Override
    public Object postProcessAfterInitialization(Object arg0, String arg1)
            throws BeansException {
        System.out.println("JAVABean postProcessAfterInitialization");
        return null;
    }

    @Override
    public Object postProcessBeforeInitialization(Object arg0, String arg1)
            throws BeansException {
        System.out.println("JAVABean postProcessBeforeInitialization");
        return null;
    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory arg0)
            throws BeansException {
        System.out.println("JAVABean postProcessBeanFactory");

    }

}
配置文件iocContext.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:p="http://www.springframework.org/schema/p"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop 
    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    <bean id="javabean" class="com.google.aop.exception.ioc.JAVABean"
        init-method="init">
        <!-- <property name="myBean" ref="MyBean"></property> -->
    </bean>
    <!--
        <bean id="MyBean" class="com.google.aop.exception.ioc.MyBean"
        init-method="init"> <property name="javabean"
        ref="javabean"></property> </bean>
    -->
</beans>
控制台输出：
JAVABean 初始化成功
JAVABean setBeanFactory
JAVABean afterPropertiesSet
JAVABean init
JAVABean postProcessBeanFactory
可见是先实例化类->初始化属性->设置创建这个类的beanFactory引用->调用afterPropertiesSet->调用init初始化方法->调用postProcessBeanFactory

现在让JAVABean和MyBean互相引用，看IOC是怎么解决这个问题
package com.google.aop.exception.ioc;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

public class JAVABean implements InitializingBean, DisposableBean,
        BeanFactoryAware, BeanPostProcessor, BeanFactoryPostProcessor {
    private MyBean myBean;

    public MyBean getMyBean() {
        return myBean;
    }

    public void setMyBean(MyBean myBean) {
        System.out.println("JAVABean 中初始化 属性myBean");
        this.myBean = myBean;
    }

    public JAVABean() {
        System.out.println("JAVABean 初始化成功");
    }

    public void init() {
        System.out.println("JAVABean init");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("JAVABean afterPropertiesSet");

    }

    @Override
    public void destroy() throws Exception {
        System.out.println("JAVABean destroy");

    }

    @Override
    public void setBeanFactory(BeanFactory arg0) throws BeansException {
        System.out.println("JAVABean setBeanFactory");

    }

    @Override
    public Object postProcessAfterInitialization(Object arg0, String arg1)
            throws BeansException {
        System.out.println("JAVABean postProcessAfterInitialization");
        return null;
    }

    @Override
    public Object postProcessBeforeInitialization(Object arg0, String arg1)
            throws BeansException {
        System.out.println("JAVABean postProcessBeforeInitialization");
        return null;
    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory arg0)
            throws BeansException {
        System.out.println("JAVABean postProcessBeanFactory");

    }

}
MyBean:
package com.google.aop.exception.ioc;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

public class MyBean implements InitializingBean, DisposableBean,
        BeanFactoryAware, BeanPostProcessor, BeanFactoryPostProcessor {
    private JAVABean javabean;

    public MyBean() {
        System.out.println("MyBean 初始化成功");
    }

    public String get() {
        return "Mybean";
    }

    public void init(){
        System.out.println("MyBean init");
    }
    public JAVABean getJavabean() {
        return javabean;
    }

    public void setJavabean(JAVABean javabean) {
        this.javabean = javabean;
        System.out.println("MyBean 属性设置成功");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("MyBean  afterPropertiesSet");

    }

    @Override
    public void destroy() throws Exception {
        System.out.println("MyBean  destroy");

    }

    @Override
    public void setBeanFactory(BeanFactory arg0) throws BeansException {
        System.out.println("MyBean  setBeanFactory");
    }

    @Override
    public Object postProcessAfterInitialization(Object arg0, String arg1)
            throws BeansException {
        System.out.println("MyBean  postProcessAfterInitialization");
        return null;
    }

    @Override
    public Object postProcessBeforeInitialization(Object arg0, String arg1)
            throws BeansException {
        System.out.println("MyBean  postProcessBeforeInitialization");
        return null;
    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory arg0)
            throws BeansException {
        System.out.println("MyBean  postProcessBeanFactory");

    }

}
iocContext.xml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:p="http://www.springframework.org/schema/p"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop 
    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    <bean id="javabean" class="com.google.aop.exception.ioc.JAVABean"
        init-method="init">
        <property name="myBean" ref="MyBean"></property>
    </bean>

    <bean id="MyBean" class="com.google.aop.exception.ioc.MyBean"
        init-method="init">
        <property name="javabean" ref="javabean"></property>
    </bean>

</beans>
控制台输出:
JAVABean 初始化成功
MyBean 初始化成功
MyBean 属性设置成功
MyBean  setBeanFactory
MyBean  afterPropertiesSet
MyBean init
JAVABean 中初始化 属性myBean
JAVABean setBeanFactory
JAVABean afterPropertiesSet
JAVABean init
JAVABean postProcessBeanFactory
MyBean  postProcessBeanFactory
由结果可知，当IOC容器初始化JAVABean后进行属性初始化，发现MyBean这类属性还没初始化，则先初始化Mybean类直到调用他的init方法，之后再回到JAVABean类初始化，将Mybean引用赋给JavaBean

posted on 2010-11-10 16:27 羔羊 阅读(410) 评论(0)  编辑  收藏 所属分类: IOC