springboot first examle

项目基于springboot 2.2.5.RELEASE版本，官网文档链接地址如下：

https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle

使用maven作为项目的构建工具，创建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.king</groupId>
    <artifactId>springboot-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <name>springboot-demo</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.5.RELEASE</version>
    </parent>

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

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

添加Sample代码

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
public class HelloWorld {
    @RequestMapping("/")
    String home() {
        return "Hello World!";
    }

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

执行mvn clean compile对项目进行编译

执行mvn spring-boot:run运行程序，访问http://localhost:8080可以查看到Hello World!字样，即表示应用启动成功

执行mvn package spring-boot:repackage可在target目录下生成可执行jar包,包名为${artifactId}-${version}.jar，如果使用上述pom.xml，生产的jar名为springboot-demo-1.0-SNAPSHOT.jar

执行java -jar target/springboot-demo-1.0-SNAPSHOT.jar即可运行，访问http://localhost:8080可以查看到Hello World!