spring学习笔记（1）

@SpringBootApplication：是Sprnig Boot项目的核心注解，目的是开启自动配置
官方解释：
Many Spring Boot developers like their apps to use auto-configuration, component scan and be able to define extra configuration on their "application class". A single @SpringBootApplication annotation can be used to enable those three features, that is:

@EnableAutoConfiguration: enable Spring Boot’s auto-configuration mechanism

@ComponentScan: enable @Component scan on the package where the application is located (see the best practices)

@Configuration: allow to register extra beans in the context or import additional configuration classes

`public @interface SpringBootApplication {
@AliasFor(
annotation = EnableAutoConfiguration.class
)
Class<?>[] exclude() default {};

@AliasFor(
    annotation = EnableAutoConfiguration.class
)
String[] excludeName() default {};

@AliasFor(
    annotation = ComponentScan.class,
    attribute = "basePackages"
)
String[] scanBasePackages() default {};

@AliasFor(
    annotation = ComponentScan.class,
    attribute = "basePackageClasses"
)
Class<?>[] scanBasePackageClasses() default {};

}`

pom.xml文件
依赖 spring-boot-starter-parent
-自动引入 spring-boot-dependencies
-自动配置 spring-boot-maven-plugin
反之，如果不依赖 spring-boot-starter-parent的话，需要手工添加如下