Spring Boot依赖spring-boot-starter-parent是干啥的？

你的项目pom.xml文件中，应该存在如下代码：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.RELEASE</version>
</parent>

    
    

你是否知道这是干啥的？
这是Spring Boot的父级依赖，这样当前的项目就是Spring Boot项目了。
spring-boot-starter-parent 是一个特殊的starter，它用来提供相关的Maven默认依赖。使用它之后，常用的包依赖可以省去version标签。
当我们搭建web应用的时候，可以像下面这样添加spring-boot-starter-web依赖：

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

    
    

简单的演示下 Spring Boot 项目：

maven文件看起来是这个样子的:

<?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>
<span class="token operator">&lt;</span>groupId<span class="token operator">&gt;</span>springBootLearn<span class="token operator">&lt;</span><span class="token operator">/</span>groupId<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>artifactId<span class="token operator">&gt;</span>springBootLearn<span class="token operator">&lt;</span><span class="token operator">/</span>artifactId<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>version<span class="token operator">&gt;</span><span class="token number">1.0</span><span class="token operator">-</span><span class="token constant">SNAPSHOT</span><span class="token operator">&lt;</span><span class="token operator">/</span>version<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token keyword">parent</span><span class="token operator">&gt;</span>
    <span class="token operator">&lt;</span>groupId<span class="token operator">&gt;</span>org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>boot<span class="token operator">&lt;</span><span class="token operator">/</span>groupId<span class="token operator">&gt;</span>
    <span class="token operator">&lt;</span>artifactId<span class="token operator">&gt;</span>spring<span class="token operator">-</span>boot<span class="token operator">-</span>starter<span class="token operator">-</span><span class="token keyword">parent</span><span class="token operator">&lt;</span><span class="token operator">/</span>artifactId<span class="token operator">&gt;</span>
    <span class="token operator">&lt;</span>version<span class="token operator">&gt;</span><span class="token number">2.0</span><span class="token number">.0</span><span class="token punctuation">.</span><span class="token constant">RELEASE</span><span class="token operator">&lt;</span><span class="token operator">/</span>version<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span><span class="token keyword">parent</span><span class="token operator">&gt;</span>

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

HelloworldController.java

@RestController
public class HelloworldController {
    @RequestMapping("/")
    public String say(){
        return "Hello Spring Boot";
    }
}

  
  

Application.java

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Ch1Application.class, args);
    }
}

  
  

运行main方法，启动项目，然后在浏览器访问http://localhost:8080,就能看到 “Hello Spring Boot”。

---

你的项目pom.xml文件中，应该存在如下代码：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.RELEASE</version>
</parent>

  
  

你是否知道这是干啥的？
这是Spring Boot的父级依赖，这样当前的项目就是Spring Boot项目了。
spring-boot-starter-parent 是一个特殊的starter，它用来提供相关的Maven默认依赖。使用它之后，常用的包依赖可以省去version标签。
当我们搭建web应用的时候，可以像下面这样添加spring-boot-starter-web依赖：

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

  
  

简单的演示下 Spring Boot 项目：

maven文件看起来是这个样子的:

<?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>
<span class="token operator">&lt;</span>groupId<span class="token operator">&gt;</span>springBootLearn<span class="token operator">&lt;</span><span class="token operator">/</span>groupId<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>artifactId<span class="token operator">&gt;</span>springBootLearn<span class="token operator">&lt;</span><span class="token operator">/</span>artifactId<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>version<span class="token operator">&gt;</span><span class="token number">1.0</span><span class="token operator">-</span><span class="token constant">SNAPSHOT</span><span class="token operator">&lt;</span><span class="token operator">/</span>version<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token keyword">parent</span><span class="token operator">&gt;</span>
    <span class="token operator">&lt;</span>groupId<span class="token operator">&gt;</span>org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>boot<span class="token operator">&lt;</span><span class="token operator">/</span>groupId<span class="token operator">&gt;</span>
    <span class="token operator">&lt;</span>artifactId<span class="token operator">&gt;</span>spring<span class="token operator">-</span>boot<span class="token operator">-</span>starter<span class="token operator">-</span><span class="token keyword">parent</span><span class="token operator">&lt;</span><span class="token operator">/</span>artifactId<span class="token operator">&gt;</span>
    <span class="token operator">&lt;</span>version<span class="token operator">&gt;</span><span class="token number">2.0</span><span class="token number">.0</span><span class="token punctuation">.</span><span class="token constant">RELEASE</span><span class="token operator">&lt;</span><span class="token operator">/</span>version<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span><span class="token keyword">parent</span><span class="token operator">&gt;</span>