Spring注解驱动之BeanFactoryPostProcessor原理解析

package com.meimeixia.ext;
import java.util.Arrays;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.stereotype.Component;

@Component
public class MyBeanFactoryPostProcessor implements BeanFactoryPostProcessor {

	@Override
	public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
		System.out.println("MyBeanFactoryPostProcessor...postProcessBeanFactory..."); // 这个时候我们所有的bean还没被创建
		                                                                              // 但是我们可以看一下通过Spring给我们传过来的这个beanFactory，我们能拿到什么
		int count = beanFactory.getBeanDefinitionCount(); // 我们能拿到有几个bean定义
		String[] names = beanFactory.getBeanDefinitionNames(); // 除此之外，我们还能拿到每一个bean定义的名字
		System.out.println("当前BeanFactory中有" + count + "个Bean");
		System.out.println(Arrays.asList(names));
	}
}

package com.meimeixia.ext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import com.meimeixia.bean.Blue;

@ComponentScan("com.meimeixia.ext")
@Configuration
public class ExtConfig {
	@Bean
	public Blue blue() {
		return new Blue();
	}	
}

package com.meimeixia.bean;

public class Blue {

	public Blue() {
		System.out.println("blue...constructor");
	}
	
	public void init() {
		System.out.println("blue...init...");
	}
	
	public void destory() {
		System.out.println("blue...destory...");
	}
}

package com.meimeixia.test;
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import com.meimeixia.ext.ExtConfig;

public class IOCTest_Ext {
	
	@Test
	public void test01() {
		AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(ExtConfig.class);
		// 关闭容器
		applicationContext.close();
	}
}