FactoryBean执行方式

xml定义一个factory bean，对应的对象是UserFactoryBean

public static void main(String[] args) {
        BeanFactory beanFactory = new ClassPathXmlApplicationContext("classpath:META-INF\\bean-creation-context.xml");
        User user3 = beanFactory.getBean("user-by-factoryBean", User.class);
        System.out.println(user3);

 

public class UserFactoryBean implements FactoryBean {
    @Override
    public User getObject() throws Exception {
        User user = new User();
        user.setId(3);
        user.setName("lhz factoryBean");
        return user;
    }



    @Override
    public Class getObjectType() {
        return User.class;
    }
}

追踪User user3 = beanFactory.getBean("user-by-factoryBean", User.class);创建过程

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进去AbstractBeanFactory，跳到断点处，进入子类AbstractAutowireCapableBeanFactory重写的getObjectForBeanInstance方法

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再进去AbstractAutowireCapableBeanFactory，走到断点，最终还是调用父类AbstractBeanFactory的
getObjectForBeanInstance方法

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进入

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进入FactoryBeanRegistrySupport，

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跳到这个类的doGetObjectFromFactoryBean方法

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这就是我们实现FactoryBean接口的实现方法，再返回这个对象

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并放入缓存

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