测试类入口:
AnnotationConfigApplicationContextTests test = new AnnotationConfigApplicationContextTests();
test.scanAndRefresh();
类图如下。
由类机构图可以知道AnnotationConfigApplicationContext同时也是一个Registry、因此同事也具有注册bean定义的功能
创建AnnotationConfigApplicationContext的同时由父类GenericApplicationContext负责创建内部refresh工厂类
private final DefaultListableBeanFactory beanFactory;
@Nullable
private ResourceLoader resourceLoader;
private final DefaultListableBeanFactory beanFactory;
public class GenericApplicationContext extends AbstractApplicationContext implements BeanDefinitionRegistry {
/**
* Create a new GenericApplicationContext.
* @see #registerBeanDefinition
* @see #refresh
* 由此可见内部默认的bean工厂依然是DefaultListableBeanFactory类型
*/
public GenericApplicationContext() {
this.beanFactory = new DefaultListableBeanFactory();
}
}
1.从测试类开始。一步一步debug、带着问题逐渐深入。
private final AnnotatedBeanDefinitionReader reader;
private final ClassPathBeanDefinitionScanner scanner;
/**
* Create a new AnnotationConfigApplicationContext that needs to be populated
* through {@link #register} calls and then manually {@linkplain #refresh refreshed}.
*/
public AnnotationConfigApplicationContext() {
this.reader = new AnnotatedBeanDefinitionReader(this);
this.scanner = new ClassPathBeanDefinitionScanner(this);
}
Q.E.D.
