@Configuration类的加载在什么环节

在Context.refresh的时候

• Context.refresh
• invokeBeanFactoryPostProcessors
• invokeBeanDefinitionRegistryPostProcessors

/**
	 * Invoke the given BeanDefinitionRegistryPostProcessor beans.
	 */
	private static void invokeBeanDefinitionRegistryPostProcessors(
			Collection<? extends BeanDefinitionRegistryPostProcessor> postProcessors, BeanDefinitionRegistry registry) {

		for (BeanDefinitionRegistryPostProcessor postProcessor : postProcessors) {
			postProcessor.postProcessBeanDefinitionRegistry(registry);
		}
	}

• 其后一个postProcessor就是org.springframework.context.annotation.ConfigurationClassPostProcessor

/**
	 * Build and validate a configuration model based on the registry of
	 * {@link Configuration} classes.
	 */
	public void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {
...

• 最终会扫描class文件，代码中resourcePattern = */*.class

private Set<BeanDefinition> scanCandidateComponents(String basePackage) {
		Set<BeanDefinition> candidates = new LinkedHashSet<>();
		try {
			String packageSearchPath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +
					resolveBasePackage(basePackage) + '/' + this.resourcePattern;
			Resource[] resources = getResourcePatternResolver().getResources(packageSearchPath);
			boolean traceEnabled = logger.isTraceEnabled();
			boolean debugEnabled = logger.isDebugEnabled();
			for (Resource resource : resources) {

调用栈

"main@1" prio=5 tid=0x1 nid=NA runnable
  java.lang.Thread.State: RUNNABLE
	  at org.springframework.context.annotation.ComponentScanAnnotationParser.parse(ComponentScanAnnotationParser.java:132)
	  at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:295)
	  at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:249)
	  at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:206)
	  at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:174)
	  at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:319)
	  at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:236)
	  at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:280)
	  at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:96)
	  at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:707)
	  at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:533)
	  - locked <0x7f5> (a java.lang.Object)
	  at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
	  at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750)
	  at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
	  at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
	  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237)
	  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
	  at com.example.demo.DemoApplication.main(DemoApplication.java:11)