package com.example.demo;

 import org.springframework.boot.SpringApplication;

 import org.springframework.boot.autoconfigure.SpringBootApplication;

 import org.springframework.context.annotation.ComponentScan;

 @SpringBootApplication

 @ComponentScan("com.example.helloweb") //扫描所需要的包

 public class DemoApplication {

     public static void main(String[] args) {

         SpringApplication.run(DemoApplication.class, args);

     }

 }

 package com.example.helloweb;

 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;

 @Controller

 public class HelloWord {

     /**

      * @Controller 和 @ResponseBody 配合相当于 @RestController,

      * 返回前端页面的都是 json 格式数据。

      * @return

      */

     @RequestMapping("/hello")

     public @ResponseBody String index () {

         System.out.println("欢迎进入SpringBoot");

         return "Hello World!";

     }

 }