循环、覆盖自定义

循环依赖和bean的覆盖重写定义

源码里：

AbstractApplicationContext.java ：

​ refresh()

​ ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

​ refreshBeanFactory();

AbstractRefreshableApplicationContext.java：

​ refreshBeanFactory()

​ customizeBeanFactory(beanFactory);

protected void customizeBeanFactory(DefaultListableBeanFactory beanFactory) {
		if (this.allowBeanDefinitionOverriding != null) {
			//默认为ture,允许覆盖bean的定义信息
			beanFactory.setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
		}
		if (this.allowCircularReferences != null) {
			//默认为true,允许循环引用
			beanFactory.setAllowCircularReferences(this.allowCircularReferences);
		}
	}

可以对其已经定义好的信息进行重写定义：

继承ClassPathXmlApplicationContext 它可以重写AbstractRefreshableApplicationContext.java—》customizeBeanFactory(DefaultListableBeanFactory beanFactory)

	public class A extends ClassPathXmlApplicationContext {

	@Override
	protected void customizeBeanFactory(DefaultListableBeanFactory beanFactory) {
		super.setAllowCircularReferences(false);
        super.setAllowBeanDefinitionOverriding(false);
		super.customizeBeanFactory(beanFactory);
	}
}