新建Maven 然后我们导入web 的 GAV 和 SpringBoot 的 parent  最后我们测试：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.4.RELEASE</version>
    </parent>


    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

    </dependencies>

 

package com.xianyu.Test;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MainApplication {
    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class,args);
    }
}

启动类Application

package com.xianyu.Test.Controller;


import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

@RestController //Controller + ResponseBody     之前说过的
public class HelloController {

    @RequestMapping("/hello")
    public String testMapper1(){
        return "你好！世界！";
    }

}

Controller 控制器

运行：

 

 

打jar包还是老样子  直接插件 然后打包即可【先清除下】

插件就是：

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>