2. 创建第一个SpringBoot的项目

2.1. 使用start.spring.io

2.2. sts构建Spring Boot项目

Eclipse + spring插件:

https://spring.io/tools

2.3. Intellij IDEA构建Spring Boot项目

2.4. Maven方式构建

|__01-springboot-hello

2.4.1. 创建maven工程

2.4.2. 添加Springboot的依赖

修改pom.xml

添加parent

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.4.4</version>
    <relativePath/> <!-- lookup parent from repository -->
 </parent>

修改打包方式

<packaging>jar</packaging>

添加依赖(starter)

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

完整的pom

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>


    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.neuedu</groupId>
    <artifactId>spring-boot-mvn</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>


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


</project>

2.4.2.3. 创建IndexController返回json数据

package com.neuedu.mvn.controller;

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

import java.util.HashMap;
import java.util.Map;

@RestController
public class UserController {

    /**
     * http://127.0.0.1:8080/index
     * @return
     */
    @RequestMapping("/index")
    Map hello(){
        Map map = new HashMap<>();
        map.put("success",true);
        map.put("msg","成功了");


        return map;
    }
}

2.4.2.4. 入口程序启动

1. 在类上声明@SpringBootApplication注解
2. 添加启动的main函数

package com.neuedu.mvn;

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

@SpringBootApplication
public class App {

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

2. 访问：

http://127.0.0.1:8080/index