spring中factoryBean的一些事儿

package com.spring.bean;

import org.springframework.beans.factory.FactoryBean;
import org.springframework.stereotype.Component;

@Component
public class FacotryBeanDemo  implements FactoryBean {
    @Override
    public Object getObject() throws Exception {
        return new Student();
    }

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

    @Override
    public boolean isSingleton() {
        return FactoryBean.super.isSingleton();
    }
}

package com.spring.bean;

import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;

@Data
public class Student extends Person  {

    private String name;

    private  int age;

    @Override
    public String show(String str) {
        System.out.println("Studeng:test()");
        return str;
    }

}

    @org.junit.Test
    public void test2(){
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        Student bean = (Student)context.getBean("facotryBeanDemo");
        FacotryBeanDemo facotryBeanDemo = (FacotryBeanDemo)context.getBean("&facotryBeanDemo");
        System.out.println("Student:"+bean);
        System.out.println("FacotryBeanDemo:"+facotryBeanDemo);
    }

从上面代码可以看出即使student没有注解，也没有通过xml配置，最后也交给了spring管理，这是因为通过factoryBeanDemo将其交给了spring管理，但是其不在单例池中，而是在factoryBeanObjectCache缓存中；

源码如下：