查看“Spring Boot-HelloWorld”的源代码

=== Spring Boot 2 入门 ===

==== 系统要求 ====
Java 8 & 兼容 java 14

Maven 3.3+

idea 2019.12

==== maven 设置 ====
<syntaxhighlight lang="xml">
<mirrors>
    <mirror>
        <id>nexus-aliyun</id>
        <mirrorOf>central</mirrorOf>
        <name>Nexus aliyun</name>
        <url>http://maven.aliyun.com/nexus/content/groups/public</url>
    </mirror>
</mirrors>

<profiles>
    <profile>
        <id>jdk-1.8</id>
        <activation>
            <activeByDefault>true</activeByDefault>
            <jdk>1.8</jdk>
        </activation>
        <properties>
            <maven.compiler.source>1.8</maven.compiler.source>
            <maven.compiler.target>1.8</maven.compiler.target>
            <maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
        </properties>
    </profile>
</profiles>
</syntaxhighlight>https://www.bilibili.com/video/BV19K4y1L7MT?p=5




=== Java代码 ===

==== MainApplication.java ====
<syntaxhighlight lang="java">
package io.github.jihch.boot;

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


/**
 * 主程序类
 * @SpringBootApplication：这是一个 Spring Boot 应用
 */
@SpringBootApplication
public class MainApplication {

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

}

</syntaxhighlight>



==== HelloController.java ====
<syntaxhighlight lang="java">
package io.github.jihch.boot.controller;

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

@RestController
public class HelloController {

    @RequestMapping("/hello")
    public String handle01() {
        return "Hello, Spring Boot 2！";
    }

}

</syntaxhighlight>测试URL：http://localhost:8080/hello




=== Application.yml ===

==== 修改 tomcat 监听端口 ====
<syntaxhighlight lang="yaml">
server:
  port: 8888
</syntaxhighlight>



==== 官方文档配置属性说明 ====
https://docs.spring.io/spring-boot/docs/2.7.8/reference/html/application-properties.html#appendix.application-properties




=== 创建可执行文件 ===
https://docs.spring.io/spring-boot/docs/2.7.8/reference/html/getting-started.html#getting-started.first-application.executable-jar

==== 在 pom.xml 中引入插件 ====
<syntaxhighlight lang="xml">
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</syntaxhighlight>


==== 清理、打包 ====
[[文件:IDEA 中调用 Maven 的生命周期阶段1.png|无|缩略图]]
在 target 目录下得到可执行文件 boot-01-helloworld-1.0-SNAPSHOT.jar




==== 在命令行中独立运行 ====
<syntaxhighlight lang="powershell">
E:\record\2023\1\28\boot-01-helloworld\target>java -jar boot-01-helloworld-1.0-SNAPSHOT.jar

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.4.RELEASE)

2023-02-01 14:35:45.878  INFO 7620 --- [           main] io.github.jihch.boot.MainApplication     : Starting MainApplication v1.0-SNAPSHOT on SK-20210414CLPG with PID 7620 (E:\record\2023\1\28\boot-01-helloworld\target\boot-01-helloworld-1.0-SNAPSHOT.jar started by Administrator in E:\record\2023\1\28\boot-01-helloworld\target)
2023-02-01 14:35:45.880  INFO 7620 --- [           main] io.github.jihch.boot.MainApplication     : No active profile set, falling back to default profiles: default
2023-02-01 14:35:47.311  INFO 7620 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8888 (http)
2023-02-01 14:35:47.324  INFO 7620 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2023-02-01 14:35:47.325  INFO 7620 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.38]
2023-02-01 14:35:47.395  INFO 7620 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2023-02-01 14:35:47.395  INFO 7620 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1446 ms
2023-02-01 14:35:47.542  INFO 7620 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2023-02-01 14:35:47.719  INFO 7620 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8888 (http) with context path ''
2023-02-01 14:35:47.728  INFO 7620 --- [           main] io.github.jihch.boot.MainApplication     : Started MainApplication in 2.511 seconds (JVM running for 3.704)
</syntaxhighlight>





=== 注意事项 ===
windows 中，在命令行中运行可执行文件时，如果遇到鼠标点击就会暂停运行的情况，可能是因为启用了“快速编辑模式”
[[文件:Windows 命令行快速编辑模式.png|无|缩略图|591x591像素]]
取消掉勾选就可以了