The first Spring Boot application

Outline

Here we use Intellij IDEA to create a Spring Boot project.

# Open IDEA -> New Project -> Spring Initializr

# Fill Project Information

# Select the desired dependence Spring Boot version and Web Development

# Save the project to a specified directory

# Project directory structure

Project directory structure is created as follows:

│  .gitignore
│  pom.xml
│
│
└─src
    ├─main
    │  ├─java
    │  │  └─com
    │  │      └─funtl
    │  │          └─hello
    │  │              └─spring
    │  │                  └─boot
    │  │                          HelloSpringBootApplication.java
    │  │
    │  └─resources
    │      │  application.properties
    │      │
    │      ├─static
    │      └─templates
    └─test
        └─java
            └─com
                └─funtl
                    └─hello
                        └─spring
                            └─boot
                                    HelloSpringBootApplicationTests.java

• .gitignore: Git filtering profile
• pom.xml: Maven dependency management profiles
• HelloSpringBootApplication.java: program entry
• resources: Resources files directory
  • static: static resource file directory
  • templates: template resource file directory
  • application.properties:Spring Boot configuration file will be replaced with the actual development YAML language configuration (application.yml)

# pom.xml

<?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>

    <groupId>com.snake</groupId>
    <artifactId>hello-spring-boot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>hello-spring-boot</name>
    <description></description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

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

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

 

• parent：继承了 Spring Boot 的 Parent，表示我们是一个 Spring Boot 工程
• spring-boot-starter-web：包含了 spring-boot-starter 还自动帮我们开启了 Web 支持

#功能演示

我们创建一个 Controller 来演示一下 Spring Boot 的神奇功能

package com.snaek.hello.spring.boot.controller;

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

@RestController
public class HelloController {

    @RequestMapping(value = "", method = RequestMethod.GET)
    public String sayHi() {
        return "Hello Spring Boot";
    }
}

 

启动 HelloSpringBootApplication 的 main() 方法，浏览器访问 http://localhost:8080 可以看到：

Hello Spring Boot

 

#神奇之处

• 没有配置 web.xml
• 没有配置 application.xml，Spring Boot 帮你配置了
• 没有配置 application-mvc.xml，Spring Boot 帮你配置了
• 没有配置 Tomcat，Spring Boot 内嵌了 Tomcat 容器