创建好了SpringBoot工程之后，我们看看项目结构
这个结构看起来非常的熟悉，如果之前一直使用的是maven来进行项目管理的话。
基本没有什么差别，好像没什么介绍的
这里需要注意的是main目录下面
有一个resources目录
static目录下面是存放静态文件的，比如js，image等
templates下面是存放页面资源等
application.properties 是SpringBoot的唯一配置文件，核心文件。
在java的类目录下，SpringBoot为我们自动创建了一个类
SpringbootApplication.java
@SpringBootApplication // SpringBoot 核心注解，主要用于开启spring自动配置
public class SpringbootApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootApplication.class, args);
}
}
这个类是SpringBoot的核心类
我们直接运行这个main方法，也就启动了SpringBoot的服务
. ____ _ __ _ _
/\ / _' __ _ () __ __ _ \ \ \ \
( ( )___ | '_ | '| | ' / _` | \ \ \ \
\/ __)| |)| | | | | || (_| | ) ) ) )
' |__| .__|| ||| |__, | / / / /
=========||==============|__/=///_/
:: Spring Boot :: (v2.4.1)
2020-12-15 17:38:24.144 INFO 3695 --- [ main] c.d.springboot.SpringbootApplication : Starting SpringbootApplication using Java 1.8.0_251 on JaydeMacBook-Pro.local with PID 3695 (/Users/jay/IdeaProjects/springboot/target/classes started by jay in /Users/jay/IdeaProjects/springboot)
2020-12-15 17:38:24.146 INFO 3695 --- [ main] c.d.springboot.SpringbootApplication : No active profile set, falling back to default profiles: default
2020-12-15 17:38:24.657 INFO 3695 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2020-12-15 17:38:24.662 INFO 3695 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2020-12-15 17:38:24.662 INFO 3695 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.41]
2020-12-15 17:38:24.701 INFO 3695 --- [ main] o.a.c.c.C.[.[localhost].[/springboot] : Initializing Spring embedded WebApplicationContext
2020-12-15 17:38:24.701 INFO 3695 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 528 ms
2020-12-15 17:38:24.794 INFO 3695 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-12-15 17:38:24.914 INFO 3695 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path '/'
2020-12-15 17:38:24.922 INFO 3695 --- [ main] c.d.springboot.SpringbootApplication : Started SpringbootApplication in 1.011 seconds (JVM running for 1.385)
2020-12-15 17:38:29.918 INFO 3695 --- [nio-8090-exec-1] o.a.c.c.C.[.[localhost].[/springboot] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-12-15 17:38:29.919 INFO 3695 --- [nio-8090-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2020-12-15 17:38:29.919 INFO 3695 --- [nio-8090-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 0 ms
这样SpringBoot项目就起来的，看到了启动了Tomcat服务，端口是8080
当然这些都是可以修改的，后面我们会讲解如何修改端口以及上下文。
