I. Development Environment

1.Eclipse STS

2.maven 3.6.0 (Maven installation and configuration, etc. will not be discussed here, not a small partner can Baidu)

3.jdk1.8

4.SpringBoot2.1.5

II. Construction of Spring Boot project

1. Using maven to build SpringBoot project

When you first create a project, it will take a long time to download SpringBoot2.1.5 related jar package, need to be patient

2.SpringBoot starter

It is actually a collection jar package of so-called springBoot starter. SprigBoot offers a total of 44 starters.

2.1spring-boot-starter-web

Support full-stack web development, including romcat and springMVC such as jar

2.2 spring-boot-starter-jdbc

Set in a spring supported manner jdbc jar package database

2.3 spring-boot-starter-redis

Redis supports key-value store database operations

Three, Spring Boot entry HelloWorld

1. Write HelloWorld return of Controller

package com.example.demo.controller;

import java.util.HashMap;
import java.util.Map;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class HelloWorldController {
    @RequestMapping("/hello")
    @ResponseBody
    public Map<String, Object> showHelloWorld(){
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "HelloWorld");
        return map;
    }
}

2.编写SpringBoot 启动类（创建工程的时候会自动生成一个启动器类）

package com.example.demo;

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

@SpringBootApplication
public class DemoApplication {

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

}

3.关于编写启动器需要注意的问题

启动器存放的位置。启动器可以和controller位于同一个包下，或者位于controller的上一级包中，但是不能放到controller的平级以及子包下。

4.启动SpringBoot

5.浏览器查看结果

总结

这就是SpringBoot的helloworld的入门程序，是不是特别简单，相比以前的开发少了很多的配置，只需要在pom.xml中添加一个web的启动器即可完成所有配置，但缺点在于第一次配置启动器，eclipse会自动下载相关的jar包，很耗时间。下一篇介绍如何在SpringBoot中整合WEB开发。

SpringBoot Getting Started Demo