1、BeanFactory是Spring 底层IoC容器

（1）创建DefaultListableBeanFactory容器，通过源码可以看出其继承了BeanDefinitionRegistry

（2）读取配置文件

通过XmlBeanDefinitionReader加载配置，通过源码得知，XmlBeanDefinitionReader的构造函数的参数为BeanDefinitionRegistry：

 

引起可以直接把DefaultListableBeanFactory直接装配进去

XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(beanFactory);

package org.binsoft.thinking.in.spring.ioc.overview.container;

import org.binsoft.thinking.in.spring.ioc.overview.domain.User;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;

import java.util.Map;

/**
 * {@link BeanFactory} 作为IoC容器示例
 *
 * @author Administrator
 * @version 1.0
 * @date 2021/1/2 20:47
 */
public class BeanFactoryAsIoCContainerDemo {
    public static void main(String[] args) {
        //创建BeanFactory容器
        DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
        XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(beanFactory);
        //XML 配置文件 ClassPath 路径
        String location = "classpath:/META-INF/dependency-lookup-context.xml";
        //加载配置
        int beanDefinitionsCount = reader.loadBeanDefinitions(location);
        System.out.println("Bean 定义加载的数量: " + beanDefinitionsCount);

        //不利用ApplicationContext，也可以加载文件
        lookupCollectionByType(beanFactory);

    }

    private static void lookupCollectionByType(BeanFactory beanFactory) {
        if (beanFactory instanceof ListableBeanFactory) {
            ListableBeanFactory listableBeanfactory = (ListableBeanFactory) beanFactory;
            Map<String, User> users = listableBeanfactory.getBeansOfType(User.class);
            System.out.println("查找到的所有的 User 集合对象:" + users);

        }
    }
}

2、ApplicationContext 是具备应用特性的BeanFactory超集

package org.binsoft.thinking.in.spring.ioc.overview.container;

import org.binsoft.thinking.in.spring.ioc.overview.domain.User;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Map;

/**
 * 注解能力 {@link ApplicationContext} 作为IoC容器示例
 *
 * @author Administrator
 * @version 1.0
 * @date 2021/1/2 20:47
 */

//标注Configuration注解 被CGLib 提升
@Configuration
public class AnnotationApplicationContextAsIoCContainerDemo {
    public static void main(String[] args) {
        //创建BeanFactory容器
        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
        //将当前类作为配置类
        applicationContext.register(AnnotationApplicationContextAsIoCContainerDemo.class);

        //启动应用上下文
        applicationContext.refresh();

        //不利用ApplicationContext，也可以加载文件
        lookupCollectionByType(applicationContext);

    }

    /**
     * 通过Java注解定义一个Bean
     * @return
     */
    @Bean
    public User user(){
        User user = new User();
        user.setId(8l);
        user.setName("李淳罡");
        return user;
    }

    private static void lookupCollectionByType(BeanFactory beanFactory) {
        if (beanFactory instanceof ListableBeanFactory) {
            ListableBeanFactory listableBeanfactory = (ListableBeanFactory) beanFactory;
            Map<String, User> users = listableBeanfactory.getBeansOfType(User.class);
            System.out.println("查找到的所有的 User 集合对象:" + users);

        }
    }
}