Spring Boot Learning Summary (ii)--some basic points about @springbootapplication

1. @SpringBootApplication

It is a composite annotation, in fact, for springboot applications, the most important thing is that there are only three

@Target (Elementtype.type) @Retention (retentionpolicy.runtime) @Documented @inherited
//Three of the most important @Configuration @enableautoconfiguration@componentscan
 public @interface springbootapplication{...}

It's too cumbersome to write three annotation at a time

@Configuration @enableautoconfiguration@componentscan  Public class demoapplication {    publicstaticvoid  main (string[] args) {        Springapplication.run (springboot01application. class , args);}    }

Can simplify, write a @springbootapplication one-stop compound

@SpringBootApplication  Public class demoapplication {    publicstaticvoid  main (string[] args) {        Springapplication.run (springboot01application. class , args);}    }

2. @ComponentScan

Function: Automatically scans and loads eligible component or bean definitions, then loads into containers

3, @EnableAutoConfiguration, is also a composite annotation

@Target (Elementtype.type) @Retention (rententionpolicy.runtime) @ Documented@inherited@autoconfigurationpackage@import (enableautoconfigurationimportselector.class)  public @interface enableautoconfiguration{...}

The most critical is @import, which loads all eligible @configuration configurations into the IOC container created and used by the current springboot.

With the support of the original tool class Springfactoriesloader of the spring framework, @EnableAutoConfiguration can achieve "intelligent" automation configuration.

--End--to be continued ~

Spring Boot Learning Summary (ii)--some basic points about @springbootapplication