spring boot加載機制

@SpringBootApplication作用

標注為啟動類

SpringBootApplication的注解有以下

@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 {
}

 

@SpringBootConfiguration作用

@SpringBootConfiguration點進去是  

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Configuration
public @interface SpringBootConfiguration {
}

通過@Configuration注解來加載標注有@Configuration的類

作用

1.1、@Configuration配置spring並啟動spring容器
1.2、@Configuration啟動容器+@Bean注冊Bean
1.3、@Configuration啟動容器+@Component注冊Bean

@ComponentScan作用

掃描包下的文件

@EnableAutoConfiguration作用

加載spring.factories下的類文件