@SpringBoot註解到底做了什麼，你真的瞭解嗎？

@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類

返回AutoConfigurationImportSelector.AutoConfigurationEntry基礎上， AnnotationMetadata import的@Configuration類。

autoConfigurationMetadata - 自動配置的元數據
annotationMetadata - 配置類的註釋元數據
返回：應導入自動配置
獲得配置
返回應該被視爲自動配置類名。默認情況下，此方法將使用加載候選人SpringFactoriesLoader與getSpringFactoriesLoaderFactoryClass()
元數據 - 源元數據
屬性-將annotation attributes
返回：候選配置列表
看下其中的斷言中指定的