@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
傳回AutoConfigurationImportSelector.AutoConfigurationEntry基礎上, AnnotationMetadata import的@Configuration類。
autoConfigurationMetadata - 自動配置的中繼資料
annotationMetadata - 配置類的注釋中繼資料
傳回:應導入自動配置
獲得配置
傳回應該被視為自動配置類名。 預設情況下,此方法将使用加載候選人SpringFactoriesLoader與getSpringFactoriesLoaderFactoryClass()
中繼資料 - 源中繼資料
屬性-将annotation attributes
傳回:候選配置清單
- 看下其中的斷言中指定的
META-INF/spring.factories
為我們實作了很多自動裝配
我們随便看下這個類
内嵌的 tomcat
其實就是開啟 springMVC,這隻是 sb 批量自動裝配的一個元件
ServletWebServerFactoryAutoConfiguration
自動裝配 - 啟動一個内嵌的 tomcat