springboot01、基本配置

<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.item;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Action {
    public static void main(String[] args) {
        SpringApplication.run(Action.class,args);//一定是被@SpringBootApplication标记的类
    }
}

package com.item.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
@RestController
@CrossOrigin
public class UsersController {
    @GetMapping("GetInfo")
    public Object GetInfo(){
        HashMap<String,Object> map=new HashMap<String,Object>();
        map.put("state",true);
        map.put("msg","成功");
        map.put("result","有一个字符串");
        return map;
    }
}