SpringBoot快速入门-如何新建一个SpringBoot项目之基于一个maven项目来创建

一个Java要实现SpringBoot项目，需要继承SpringBoot Parent项目，将我们的项目作为SpringBoot Parent的子项目。
有3种方法来创建一个SpringBoot项目，我们先来看第一种方法：基于一个maven项目来创建SpringBoot项目。

1）File-》New-> Project…-》选择meven-》选择“maven-archetype-quickstart”，点击next
2）输入项目名称，点击next
3）设置项目基本信息，包括group、artifact、package等，点击Finish
4）此时项目结构已经自动生成了，要让项目成为SpringBoot项目，还需要两步

<1>在pom文件中加入以下代码：

<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>2.6.6</version>
	<relativePath/> <!-- lookup parent from repository -->
</parent>

<2>在项目源码中自动生成了入口类，添加注解：@SpringBootApplication

此时原本普通的maven项目就变成了SpringBoot项目。

编写代码：

/**
 * Hello world!
 *
 */
@SpringBootApplication
@RestController
public class App
{
    public static void main( String[] args )
    {
        SpringApplication.run(App.class, args);
    }

    @GetMapping("/hello")
    public String hello(@RequestParam(value = "name", defaultValue = "World") String name) {
        return String.format("Hello %s!", name);
    }
}

运行代码，控制台输出如下：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.5.4)

2022-07-28 15:10:53.397  INFO 19312 --- [           main] org.itzhimei.App                         : Starting App using Java 1.8.0_181 on DESKTOP-UCGATI0 with PID 19312 (SpringBootFromMaven\target\classes started by itzhimei in SpringBootFromMaven)
2022-07-28 15:10:53.398  INFO 19312 --- [           main] org.itzhimei.App                         : No active profile set, falling back to default profiles: default
2022-07-28 15:10:54.084  INFO 19312 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2022-07-28 15:10:54.091  INFO 19312 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-07-28 15:10:54.091  INFO 19312 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.52]
2022-07-28 15:10:54.166  INFO 19312 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-07-28 15:10:54.166  INFO 19312 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 714 ms
2022-07-28 15:10:54.397  INFO 19312 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2022-07-28 15:10:54.403  INFO 19312 --- [           main] org.itzhimei.App                         : Started App in 1.456 seconds (JVM running for 2.308)

测试代码：
浏览器打开：http://localhost:8080/hello
输出结果：
Hello World!