通过上一篇ApplicationContext特性分析，可以得出结论BeanFactory 是 Bean容器，它不提供企业特性，比如AOP、事务以及事件等，这些都被ApplicationContext支持
源码案例分析 【https://gitee.com/icloud-iot/thinking-in-spring】
dependency-lookup-context.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<!-- <context:annotation-config/>-->
<!-- <context:component-scan base-package="org.acme" />-->
<!-- Root BeanDefinition 不需要合并，不存在 parent -->
<!-- 普通 beanDefinition GenericBeanDefinition -->
<!-- 经过合并后 GenericBeanDefinition 变成 RootBeanDefinition -->
<bean id="user" class="org.ibyte.thinking.in.spring.ioc.domain.User">
<property name="id" value="1"/>
<property name="name" value="小码哥"/>
</bean>
<!-- 普通 beanDefinition GenericBeanDefinition -->
<!-- 合并后 GenericBeanDefinition 变成 RootBeanDefinition，并且覆盖 parent 相关配置-->
<!-- primary = true , 增加了一个 address 属性 -->
<bean id="superUser" class="org.ibyte.thinking.in.spring.ioc.domain.SuperUser" parent="user"
primary="true">
<property name="address" value="深圳"/>
</bean>
<bean id="objectFactory" class="org.springframework.beans.factory.config.ObjectFactoryCreatingFactoryBean">
<property name="targetBeanName" value="user"/>
</bean>
</beans>BeanFactory 作为IoC容器
/**
* {@link BeanFactory} 作为 IoC 容器示例
*
* @author lisz ([email protected])
*/
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);
// 依赖查找集合对象
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);
}
}
}
ApplicationContext 作为IoC容器
/**
* 注解能力 {@link ApplicationContext} 作为 IoC 容器示例
*
* @author lisz ([email protected])
*/
@Configuration
public class AnnotationApplicationContextAsIoCContainerDemo {
public static void main(String[] args) {
// 创建Bean容器
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
// 将当前类 AnnotationApplicationContextAsIoCContainerDemo 作为配置类（Configuration Class）
applicationContext.register(AnnotationApplicationContextAsIoCContainerDemo.class);
// 启动应用上下文
applicationContext.refresh();
// 依赖查找集合对象
lookupCollectionByType(applicationContext);
// 关闭应用上下文
applicationContext.close();
}
/**
* 通过 Java 注解的方式，定义了一个 Bean
*/
@Bean
public User user() {
User user = new User();
user.setId(1L);
user.setName("小码哥");
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);
}
}
}