springboot系列教程（二）——Banner、CommandLineRunner、Arguments、Exit

淩亂°似流年 2022-06-03 07:09 70阅读 0赞

## Banner ##

生成工具地址 可以生成图片或者文字

[http://patorjk.com/software/taag][http_patorjk.com_software_taag]  
[http://www.network-science.de/ascii/][http_www.network-science.de_ascii]  
[http://www.degraeve.com/img2txt.php][http_www.degraeve.com_img2txt.php]

## 程序猿专用banner图 ##

${AnsiColor.BRIGHT_YELLOW}  
    //////////////////////////////////////////////////////////////////// 
    // _ooOoo_ // 
    // o8888888o // 
    // 88" . "88 // 
    // (| ^_^ |) // 
    // O\ = /O // 
    // ____/`---'\____ // 
    // .' \\| |// `. // 
    // / \\||| : |||// \ // 
    // / _||||| -:- |||||- \ // 
    // | | \\\ - /// | | // 
    // | \_| ''\---/'' | | // 
    // \ .-\__ `-` ___/-. / // 
    // ___`. .' /--.--\ `. . ___ // 
    // ."" '< `.___\_<|>_/___.' >'"". // 
    // | | : `- \`.;`\ _ /`;.`/ - ` : | | // 
    // \ \ `-. \_ __\ /__ _/ .-` / / // 
    // ========`-.____`-.___\_____/___.-`____.-'======== // 
    // `=---=' // 
    // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ // 
    // 佛祖保佑 永不宕机 永无BUG // 
    ////////////////////////////////////////////////////////////////////

**设置banner开关**

SpringApplication app = new SpringApplication(Study2Application.class);
            app.setBannerMode(Banner.Mode.OFF);
            app.run(args);

new SpringApplicationBuilder()
                    .sources(Parent.class)
                    .child(Study2Application.class)
                    .bannerMode(Banner.Mode.OFF)
                    .run(args);

## CommandLineRunner ##

> 实际应用中，我们会有在项目服务启动的时候就去加载一些数据或做一些事情这样的需求。  
> 为了解决这样的问题，Spring Boot 为我们提供了一个方法，通过实现接口 CommandLineRunner 来实现。

**新建java类MyInit1**

@Component
    @Order(value = 1)
    public class MyInit1 implements CommandLineRunner { 
        @Override
        public void run(String... strings) throws Exception {
            System.out.println(">>>>>>>>>>>>>>>服务启动执行，执行加载数据等操作 11111111 <<<<<<<<<<<<<");
        }
    }

**新建java类MyInit2**

@Component
    @Order(value = 2)
    public class MyInit2 implements CommandLineRunner { 
        @Override
        public void run(String... strings) throws Exception {
            System.out.println(">>>>>>>>>>>>>>>服务启动执行，执行加载数据等操作 22222222 <<<<<<<<<<<<<");
        }
    }

**运行结果**  
![这里写图片描述][SouthEast]

**来看看springboot在启动的时候为我们注入了哪些bean，也可以这样：**

package com.example.demo;
    
    
    import javafx.scene.Parent;
    import org.springframework.boot.Banner;
    import org.springframework.boot.CommandLineRunner;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.builder.SpringApplicationBuilder;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.annotation.Bean;
    
    import java.util.Arrays;
    
    @SpringBootApplication
    public class Study2Application {
    
        public static void main(String[] args) {
    /* SpringApplication app = new SpringApplication(Study2Application.class); app.setBannerMode(Banner.Mode.OFF); app.run(args);*/
    
            new SpringApplicationBuilder()
                    .sources(Parent.class)
                    .child(Study2Application.class)
                    .bannerMode(Banner.Mode.CONSOLE)
                    .run(args);
    
        }
    
        @Bean
        public CommandLineRunner commandLineRunner(ApplicationContext ctx){
            return args -> {
    
                System.out.println("Let's inspect the beans provided by Spring Boot:");
    
                String[] beanNames = ctx.getBeanDefinitionNames();
                Arrays.sort(beanNames);
                for (String beanName : beanNames) {
                    System.out.println(beanName);
                }
    
            };
        }
    
    }

![这里写图片描述][SouthEast 1]

## Application Arguments ##

> 如果需要访问SpringApplication.run(…)传入的参数，可以通过注解的形式注入  
> ApplicationArguments接口实例，该接口提供了一套访问String\[\]参数的方法和  
> 【不知道怎么翻译，原文是】as well as parsed option and non-option arguments:

package com.example.demo.bean;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.ApplicationArguments;
    import org.springframework.stereotype.Component;
    
    import java.util.List;
    
    /** * @author :小虎 * @date :2017/12/21 */
    
    
    @Component
    public class MyBean { 
    
        @Autowired
        public MyBean(ApplicationArguments args) {
            boolean debug = args.containsOption("debug");
            List<String> files = args.getNonOptionArgs();
            // if run with "--debug logfile.txt" debug=true, files=["logfile.txt"]
        }
    
    }

## Application Exit ##

新建java类ExitConfig

@Component
    public class ExitConfig implements ExitCodeGenerator { 
        @Override
        public int getExitCode() {
            System.out.println("定义程序退出的退出码");
            return 1024;
        }
    }

**新建退出controller**

@RestController
    public class ExitController extends ApplicationObjectSupport{ 
    
        @Autowired
        private ExitConfig exitConfig;
    
        @RequestMapping("/exit")
        public void exit(){
            SpringApplication.exit(super.getApplicationContext(),exitConfig);
        }
    }

> **访问地址** [http://localhost:8080/exit][http_localhost_8080_exit]

## 代码地址 ##

> [https://github.com/itmybaby/springboot/tree/master/study2][https_github.com_itmybaby_springboot_tree_master_study2]

[http_patorjk.com_software_taag]: http://patorjk.com/software/taag
[http_www.network-science.de_ascii]: http://www.network-science.de/ascii/
[http_www.degraeve.com_img2txt.php]: http://www.degraeve.com/img2txt.php
[SouthEast]: /images/20220603/0c786290db4d4077a8cda6de71b78070.png
[SouthEast 1]: /images/20220603/b7ae703c92404030bdf84bf4f299e77c.png
[http_localhost_8080_exit]: http://localhost:8080/exit
[https_github.com_itmybaby_springboot_tree_master_study2]: https://github.com/itmybaby/springboot/tree/master/study2