spring boot编写并运行HelloWorld服务接口

在主程序上要加包扫描注解@ComponentScan(“com.example.demo1”)

package com.example.demo1;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
@ComponentScan("com.example.demo1")
public class Demo1Application {

    public static void main(String[] args) {

        SpringApplication.run(Demo1Application.class, args);
    }
}

要运行的程序

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloWorld {
    @RequestMapping("/hello")
    public String sayHello(){
        return "hello world";
    }
}