新建一个maven工程

引入依赖项

<modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.2.11.RELEASE</version><relativePath/> <!-- lookup parent from repository -->
</parent><groupId>org.example</groupId>
<artifactId>Springboot</artifactId>
<version>1.0-SNAPSHOT</version><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency>
</dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><executions><execution><goals><goal>repackage</goal></goals></execution></executions><configuration><mainClass>org.example.Application</mainClass></configuration></plugin></plugins>
</build>

SpringBoot启动类

package org.example;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class Application {public static void main(String[] args) throws Exception {SpringApplication.run(Application.class, args);}
}

编写controller类

package org.example.control;import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class HelloController {@RequestMapping(value = "/hello")public String hello(){return "hello world";}
}

通过浏览器访问 http://localhost:8080/hello

github代码：GitHub - JJJ2018/springboot_helloworld_sample: springboot helloworld sample