springBean的生命周期

 

1、Person接口

package com.xiaostudy.service;

public interface Person {
    
    public void print();
}

2、Person的实现类PersonImple.java

package com.xiaostudy.service;

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.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class PersonImple implements Person, BeanNameAware, BeanFactoryAware, ApplicationContextAware, 
InitializingBean {
    private String name;
    
    public PersonImple() {
        System.out.println("第一步：person初始化>>>>>>>>>>>>>>");
    }
    
    public void setName(String name) {
        System.out.println("第二步：name赋值>>>>>>>>>");
        this.name = name;
    }
    
    public String getName() {
        return name;
    }

    @Override
    public void setBeanName(String beanName) {
        System.out.println("第三步：beanName=" + beanName + "||||||||||");
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        System.out.println("第四步：beanFactory=" + beanFactory + "||||||||||");
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        System.out.println("第五步：applicationContext=" + applicationContext + "||||||||||");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("第七步：afterPropertiesSet()||||||||||");
    }
    
    //跟生成代理冲突
    public void init() {
        System.out.println("第八步：init()||||||||||");
    }
    
    //这是实现Person接口的方法实现
    public void print() {
        System.out.println("第十步：PersonImple.print()>>>>>>>>>>>>>>");
    }
    
    public void destroy() {
        System.out.println("第十一步：destroy()");
    }
    
}

3、实现BeanPostProcessor接口的MyBeanPostProcessor类

package com.xiaostudy.service;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;

public class MyBeanPostProcessor implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(final Object bean, String beanName) throws BeansException {
        // TODO Auto-generated method stub
        System.out.println("第六步：postProcessBeforeInitialization()方法调用。。。第一个参数bean=" + bean + 
                            "；第二个参数beanName=" + beanName);
        //跟init-method冲突
        /*if(beanName.equals("person")) {
            // 生成代理
            return Proxy.newProxyInstance(MyBeanPostProcessor.class.getClassLoader(), bean.getClass().getInterfaces(),
                    new InvocationHandler() {
                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                    System.out.println("开始事务>>>>>>>>");
                    Object obj = method.invoke(bean, args);
                    System.out.println("关闭事务<<<<<<<<");
                    return obj;
                }
            });
        }*/
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        // TODO Auto-generated method stub
        System.out.println("第九步：postProcessAfterInitialization()方法调用。。。第一个参数arg0=" + bean + 
                            "；第二个参数arg1=" + beanName);
        return bean;
    }

}

4、测试类Test1.java

package com.xiaostudy.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.xiaostudy.service.Person;

public class Test1 {

    public static void main(String[] args) {
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        Person person = ac.getBean("person", Person.class);
        person.print();
        ((AbstractApplicationContext) ac).close();
    }

}

5、spring的配置文件applicationContext.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
                              http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="person" init-method="init" destroy-method="destroy" class="com.xiaostudy.service.PersonImple">
        <property name="name" value="xiaostudy"></property>
    </bean>
    <bean id="beanPostProcessor" class="com.xiaostudy.service.MyBeanPostProcessor"></bean>
</beans>

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具体步骤大概讲解

1、初始化对象

2、如果有属性，那么会注入赋值

3、如果实现了BeanNameAware接口，那么会执行他的setBeanName()方法

4、如果实现了BeanFactoryAware接口，那么会执行他的setBeanFactory()方法

 

5、如果实现了ApplicationContextAware接口，那么会执行他的setApplicationContext()方法

6、如果实现了BeanPostProcessor接口，那么会执行他的postProcessBeforeInitialization()方法，这个要在spring配置文件中配置bean

7、如果实现了InitializingBean接口，那么会执行他的afterPropertiesSet()方法

8、在spring配置文件中，bean的位置声明init-method，才可以用自定义初始化方法

9、如果在第六步中实现了BeanPostProcessor接口，那么，到现在的第九步执行postProcessAfterInitialization()方法

 

10、这一步开始就可以使用Bean了

11、在spring配置文件中，bean的位置声明destroy-method，才可以用自定义销毁方法

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