bean生命周期

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那在spring中bean的生命周期究竟是怎样的呢

1. 容器寻找Bean的定义信息并将其实例化

2. 使用依赖注入，spring按照Bean定义信息配置Bean的所有属性

3. 如果Bean实现了BeanNameAware接口，工厂调用Bean的SetBeanName()方法传递Bean的ID

4. 如果Bean实现了BeanFactoryAware接口，工厂调用setBeanFactory()方法传入工厂自身

5. 如果BeanPostProcessor和Bean关联，那么其postProcessBeforeInitialization()方法将被调用

6. 如果Bean指定了init-method方法，将被调用

7. 最后，如果有BeanPostProcessor和Bean关联,那么其postProcessAfterInitialization()方法将被调用

此时，Bean已经可以被应用系统使用，并将被保留在BeanFactory中知道他不再被需要。有两种可以将其从BeanFactory中删除掉的方法

①　如果Bean实现了DisposableBean接口，destroy()方法将被调用

②　如指定了定制的销毁方法，就调用这个方法

public class MyInstantiationAwareBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter{

    //before construct
    @Override public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {
        System.out.println("before beanclass : " + beanClass.getName() + beanName);
        return null;
    }

    //after construct
    @Override public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {
        System.out.println("after beanclass : " + bean + beanName);
        return true;
    }

    //before set filled
    @Override public PropertyValues postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean,
            String beanName) throws BeansException {
        System.out.println("postProcessPropertyValues");
        return super.postProcessPropertyValues(pvs, pds, bean, beanName);
    }


}

public class MyBeanPostProcessor implements BeanPostProcessor {

    //before init
    @Override public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("postProcessBeforeInitialization");
        return bean;
    }


    //after init
    @Override public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("postProcessAfterInitialization");
        return bean;
    }
}

public class Car implements BeanFactoryAware, BeanNameAware, InitializingBean, DisposableBean {

    private String brand;

    private String color;

    private int maxSpeed;

    private String beanName;

    public String getBrand() {
        return brand;
    }

    public Car() {
        System.out.println("construct");
    }

    public void setBrand(String brand) {
        System.out.println("set");
        this.brand = brand;
    }

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public int getMaxSpeed() {
        return maxSpeed;
    }

    public void setMaxSpeed(int maxSpeed) {
        this.maxSpeed = maxSpeed;
    }

    @Override
    public String toString() {
        return "Car{" + "brand=‘" + brand + ‘\‘‘ + ", color=‘" + color + ‘\‘‘ + ", maxSpeed=" + maxSpeed + ‘}‘;
    }

    //after set setBeanName
    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        System.out.println("beanFactoryAware : " + beanFactory.containsBean(beanName));
    }

    //after set filed
    @Override
    public void setBeanName(String name) {
        System.out.println("setbeanname : " + name);
        this.beanName = name;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("after properties set");
    }

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

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

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

//加载类到beanFactory,bean生命周期
@Test
public void test3() {
    String path = Demo1.class.getResource("/").getPath().concat("beans.xml");


    FileSystemResource resource = new FileSystemResource(path);

    XmlBeanFactory xmlBeanFactory = new XmlBeanFactory(resource);
    xmlBeanFactory.addBeanPostProcessor(new MyBeanPostProcessor());
    xmlBeanFactory.addBeanPostProcessor(new MyInstantiationAwareBeanPostProcessor());

    Car car = (Car)xmlBeanFactory.getBean("car1");
    Car car2 = (Car)xmlBeanFactory.getBean("car1");
    System.out.println(car.toString());
    xmlBeanFactory.destroyBean("car1");

}

bean生命周期

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原文地址：http://www.cnblogs.com/jsy306/p/4981632.html