@SpringBootApplication

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = {
		@Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
		@Filter(type = FilterType.CUSTOM,
				classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication {

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@AutoConfigurationPackage
@Import(AutoConfigurationImportSelector.class)
public @interface EnableAutoConfiguration {

	String ENABLED_OVERRIDE_PROPERTY = "spring.boot.enableautoconfiguration";

	/**
	 * Exclude specific auto-configuration classes such that they will never be applied.
	 * @return the classes to exclude
	 */
	Class<?>[] exclude() default {};

	/**
	 * Exclude specific auto-configuration class names such that they will never be
	 * applied.
	 * @return the class names to exclude
	 * @since 1.3.0
	 */
	String[] excludeName() default {};

}

注意到AutoConfigurationImportSelector类

返回AutoConfigurationImportSelector.AutoConfigurationEntry基础上， AnnotationMetadata import的@Configuration类。

autoConfigurationMetadata - 自动配置的元数据
annotationMetadata - 配置类的注释元数据
返回：应导入自动配置
获得配置
返回应该被视为自动配置类名。默认情况下，此方法将使用加载候选人SpringFactoriesLoader与getSpringFactoriesLoaderFactoryClass()
元数据 - 源元数据
属性-将annotation attributes
返回：候选配置列表
看下其中的断言中指定的