Spring Boot笔记之Hello World

谁践踏了优雅 2022-04-18 03:20 334阅读 0赞

摘要：本文将介绍如何使用Maven构建一个Spring Boot项目，并以精简的配置启动。

*  准备  
    安装Maven，从[Maven官网下载][Maven]软件包，如[apache-maven-3.6.0-bin.zip][]，解压至，将`bin`路径添加至path，栗子`C:\Users\Administrator\Downloads\apache-maven-3.5.4-bin\apache-maven-3.5.4\bin`。执行命令`mvn -v`，输出如

> Apache Maven 3.0.5 (r01de14724cdef164cd33c7c8c2fe155faf9602da; 2013-02-19 21:51:28+0800)  
> Maven home: D:\\Softwares\\apache-maven-3.0.5\\bin…  
> Java version: 1.8.0\_181, vendor: Oracle Corporation  
> Java home: C:\\Java\\jdk1.8.0\_181\\jre  
> Default locale: zh\_CN, platform encoding: GBK  
> OS name: “windows 10”, version: “10.0”, arch: “amd64”, family: “dos”

即安装成功。

*  搭建demo  
    demo项目结构如下：

> pom.xml  
> src  
> ├─main  
> │ ├─java  
> │ │ └─com  
> │ │ └─my  
> │ │ └─demo  
> │ │ └─controller  
> │ └─resources  
> │ application.properties  
> └─test  
> └─java

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.my</groupId>
        <artifactId>demo</artifactId>
        <version>0.0.1.BETA</version>
        <packaging>jar</packaging>
    
        <name>Demo</name>
        <description>Spring Boot Demo</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.5.RELEASE</version>
            <relativePath/>
        </parent>
    
        <dependencies>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-aop</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
        </dependencies>
    
        <build>
            <finalName>${project.artifactId}</finalName>
            <plugins>
            	
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <configuration>
                        <skip>true</skip>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.1</version>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    	
        <repositories>
            <repository>
                <id>public</id>
                <name>aliyun nexus</name>
                <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
                <releases>
                    <enabled>true</enabled>
                </releases>
            </repository>
        </repositories>
    </project>

src/main/resources/application.properties

server.port=80
    server.servlet.path=/

com.my.demo.Application.java

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class Application { 
        public static void main(String[] args) { 
            SpringApplication.run(Application.class, args);
        }
    }

com.my.demo.controller.HelloController.java

import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    @Controller
    public class HelloController { 
    
        @RequestMapping("/")
        @ResponseBody
        public String hello() { 
            return "Hello World :-)";
        }
    }

*  启动demo  
    在ide内run com.my.demo.Application.main()。  
    在浏览器内访问`http://localhost`，响应`Hello World :-)`。
 *  打包

mvn clean install

首次打包需要下载一些插件，打包成功后，包文件输出至`target\demo-0.0.1.BETA.jar`及`C:\Users\Administrator\.m2\repository\com\my\demo\1.0.0\demo-1.0.0.jar`

cd ..
    java -jar demo-0.0.1.BETA.jar

即可启动项目，与ide内启动相似（注意端口哦）。

[Maven]: http://maven.apache.org/download.cgi#
[apache-maven-3.6.0-bin.zip]: https://mirrors.tuna.tsinghua.edu.cn/apache/maven/maven-3/3.6.0/binaries/apache-maven-3.6.0-bin.zip