BeanFactory中bean的生命周期

• BeanFactory在初始化容器，并未实例化Bean，直到第一次访问某个Bean时才实例化目标Bean。
  

  1. 当调用者通过getBean()向容器请求某一个Bean时，如果容器注册了org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor接口，则在实例化Bean之前调用postProcessBeforeInstantiation()方法。

  2. 根据配置情况调用Bean构造函数或者工厂方法实例化Bean。

  3. 如果容器注册了 org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor接口，则在实例化Bean之后，调用该接口的postProcessAfterInstantiation()方法。

  4. 如果Bean配置了属性信息，则在设置属性之前将调用 org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor接口的postProcessPropertyValues()方法。

  5. 调用Bean的属性设置方法设置属性值。

  6. 如果Bean实现了org.springframework.beans.factory.BeanNameAware接口，则将调用setBeanName()方法，将配置文件的Bean名称设置到Bean中。

  7. 如果Bean实现了org.springframework.beans.factory.BeanFactoryAware接口，则将调用setBeanFactory()方法，将BeanFactory容器实例设置到Bean中。

  8. 如果BeanFactory装配了org.springframework.beans.factory.config.BeanPostProcessor后处理器，则将调用接口的postProcessBeforeInitialization()方法对Bean进行加工操作。

  9. 如果Bean实现了org.springframework.beans.factory.InitializingBean接口，则将调用接口的afterPropertiesSet()方法。

  10. 如果在《bean》《/bean》标签中init-method属性定义了初始化方法，则将执行这个方法。

  11. 如果BeanFactory装配了org.springframework.beans.factory.config.BeanPostProcessor后处理器，则将调用接口的postProcessAfterInitialization()方法对Bean再次进行加工操作。

  12. 对于scope=”singleton”(默认),则将Bean放入springIOC容器的缓存池中，并将引用返回给调用者，spring继续对这些Bean进行后续的生命管理。对于scope=”prototype”,则将Bean返回给调用者，调用者负责Bean的后续生命的管理，spring不再管理这个Bean的生命周期。

  13. 对于scope=”singleton”(默认),容器关闭时，将触发spring对Bean的后续生命周期的管理。如果Bean实现了org.springframework.beans.factory.DisposableBean接口，则将调用接口的destroy()方法，可以编写释放日志，记录日志等。

  14. 对于scope=”singleton”(默认)的Bean，如果在《bean》《/bean》标签中destory-method属性定义了Bean的销毁方法，则spring将执行这个方法。

package com.test.pojo;import java.beans.PropertyDescriptor;import org.springframework.beans.BeansException;import org.springframework.beans.PropertyValues;import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter;public class MyInstantiationAwareBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter {    //在实例化bean之前执行    public Object postProcessBeforeInstantiation(Class beanClass, String beanName) throws BeansException {        // TODO Auto-generated method stub        if("car".equals(beanName)){            System.out.println("这是postProcessBeforeInstantiation方法===");        }        return null;    }    //在实例化bean之后执行    public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {        // TODO Auto-generated method stub        if("car".equals(beanName)){            System.out.println("这是postProcessAfterInstantiation方法===");        }        return true;    }    //在设置那个属性的值的时候执行    public PropertyValues postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean,            String beanName) throws BeansException {        // TODO Auto-generated method stub        if("car".equals(beanName)){            System.out.println("这是postProcessPropertyValues方法===");        }        return pvs;    }}

package com.test.pojo;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;public class Car implements BeanFactoryAware,BeanNameAware,InitializingBean,DisposableBean{    private String brand;    private String color;    private int maxSpeed;    private String beanName;    private BeanFactory beanFactory;    public Car() {        System.out.println("====调用构造函数====");    }    public void afterPropertiesSet() throws Exception {        // TODO Auto-generated method stub        System.out.println("调用InitializingBean.afterPropertiesSet()。");    }    public void setBeanName(String name) {        // TODO Auto-generated method stub        System.out.println("调用了BeanNameAware.setBeanName()。");        this.beanName=name;    }    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {        // TODO Auto-generated method stub        System.out.println("调用了BeanFactoryAware.setBeanFactory()。");        this.beanFactory=beanFactory;    }    public void destroy() throws Exception {        // TODO Auto-generated method stub        System.out.println("这是DisposableBean.destory()的方法");    }    public void myInit(){        System.out.println("这是我指定的初始化方法,默认将maxSpeed设为240。");        this.maxSpeed=240;    }    public void myDestory(){        System.out.println("这是我的销毁方法");    }    public String getBrand() {        return brand;    }    public void setBrand(String brand) {        System.out.println("这是setBrand方法");        this.brand = brand;    }    public String getColor() {        return color;    }    public void setColor(String color) {        System.out.println("这是setColor方法");        this.color = color;    }    public int getMaxSpeed() {        return maxSpeed;    }    public void setMaxSpeed(int maxSpeed) {        System.out.println("这是setMaxSpeed方法");        this.maxSpeed = maxSpeed;    }    @Override    public String toString() {        return "Car [brand=" + brand + ", color=" + color + ", maxSpeed=" + maxSpeed+"]";    }}

package com.test.pojo;import org.springframework.beans.BeansException;import org.springframework.beans.factory.config.BeanPostProcessor;public class MyBeanPostProcessor implements BeanPostProcessor {    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {        // TODO Auto-generated method stub        if("car".equals(beanName)){            Car car=(Car)bean;            if(car.getColor()==null){                System.out.println("这是postProcessBeforeInitialization方法===");                car.setColor("黑色");;            }        }        return bean;    }    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {        // TODO Auto-generated method stub        if("car".equals(beanName)){            Car car=(Car)bean;            if(car.getMaxSpeed()>=200){                System.out.println("postProcessAfterInitialization方法===");                car.setMaxSpeed(200);            }        }        return bean;    }}

package com.test.spring;import org.apache.log4j.Logger;import org.springframework.beans.factory.BeanFactory;import org.springframework.beans.factory.support.DefaultListableBeanFactory;import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;import org.springframework.core.io.ClassPathResource;import org.springframework.core.io.Resource;import com.test.pojo.Car;import com.test.pojo.MyBeanPostProcessor;import com.test.pojo.MyInstantiationAwareBeanPostProcessor;public class StudentSpring {    protected Logger logger = Logger.getLogger(this.getClass());    public static void main(String[] args) {        Resource resource = new ClassPathResource("spring/applicationContext-dao.xml");        BeanFactory bf=new DefaultListableBeanFactory();        XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader((DefaultListableBeanFactory)bf);        reader.loadBeanDefinitions(resource);        ((DefaultListableBeanFactory)bf).addBeanPostProcessor(new MyBeanPostProcessor());        ((DefaultListableBeanFactory)bf).addBeanPostProcessor(new MyInstantiationAwareBeanPostProcessor());        Car car1 = (Car)bf.getBean("car");        Car car2 = (Car)bf.getBean(Car.class);        System.out.println(car1.toString()+"::"+car2.toString());        System.out.println(car1==car2);        ((DefaultListableBeanFactory)bf).destroySingletons();    }}