1. env: java 11 + IntelliJ IDEA 2021.3.2 (Community Edition)

2. file->new project->Maven:

pom.xml 需要导入的包：后面三个是jdk8升级到11后，可能会出错，需要用到的包

org.springframework.bootspring-boot-starter-parent1.2.6.RELEASE
org.springframework.bootspring-boot-starter-webjavax.xml.bindjaxb-api2.3.1javax.activationactivation1.1.1org.springframework.bootspring-boot-starter-thymeleaf

 3.编写MainApplication.java 作为启动类

@SpringBootApplication
//@ComponentScan(basePackages= "com/example/controller") 如果controller和启动类不再一个包下则需要使用组件扫描标签用于寻找，或者WhitePage error
public class MainApplication {public static void main(String[] args){SpringApplication.run(MainApplication.class, args);}
}

4.编写controller类：

@RestController
public class HelloController {@ResponseBody@RequestMapping("/hello")public String HelloController(){return "Hello this is hello handler 02";}
}

5.run main(), 测试访问地址：

http://localhost:8888/hello、

6. application.properties可配置端口等信息

spring.freemarker.checkTemplateLocation=false
server.port=8888

7.打包：

org.springframework.bootspring-boot-starter-parent1.2.6.RELEASE

cmd: jave -jar xxx.jar