Spring boot Banner和icon

Posted 2022-12-09 xiaoduup

文章目录

• Spring boot Banner和icon
• • • 上一节
    • 源码
    • Spring boot banner
    • • 自定义banner
      • • 关闭banner
        • 使用图片充当banner
      • 源码分析
    • Spring boot icon
    • • 源码分析
    • 下一节

Spring boot Banner和icon

上一节

上一节：Spring boot 基础web入门搭建

源码

源码链接地址

banner 和icon 就是做一些启动或者页面系统标识的作用；
首先创建一个web项目，如果不是很熟悉请参考上一节：Spring boot 基础web入门搭建 搭建

知识点：

1. 自定义banner 和icon
2. 初识 springboot 启动流程

Spring boot banner

springboot 自带的banner

  .   ____          _            __ _ _
 /\\\\ / ___'_ __ _ _(_)_ __  __ _ \\ \\ \\ \\
( ( )\\___ | '_ | '_| | '_ \\/ _` | \\ \\ \\ \\
 \\\\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.1.6.RELEASE)

自定义banner

1. 在resources 目录下创建banner.txt文件
2. 制作banner
   banner 制作网站
3. 修改banner.txt文件

$AnsiColor.BLUE
$spring-boot.version
$spring.application.name
$info.name
    _                             _         _
  /' )       _                   ( )       ( `\\
/' /'       (_)   _ _    _      _| | _   _  `\\ `\\
<  <   (`\\/')| | /'_` ) /'_`\\  /'_` |( ) ( )   >  >
\\  `\\  >  < | |( (_| |( (_) )( (_| || (_) | /' /'
 `\\__)(_/\\_)(_)`\\__,_)`\\___/'`\\__,_)`\\___/'(_/'

 $可以获取配置文件中的信息，  $AnsiColor.BLUE 修改字体颜色   $AnsiBackground.YELLOW修改背景颜色

从新启动,日志打印

2.1.6.RELEASE
banner-demo
banner-icon-demo
     _                             _         _
   /' )       _                   ( )       ( `\\
 /' /'       (_)   _ _    _      _| | _   _  `\\ `\\
<  <   (`\\/')| | /'_` ) /'_`\\  /'_` |( ) ( )   >  >
 \\  `\\  >  < | |( (_| |( (_) )( (_| || (_) | /' /'
  `\\__)(_/\\_)(_)`\\__,_)`\\___/'`\\__,_)`\\___/'(_/'

关闭banner

通过springapplication.setBannerMode 进行设置；banner.mode 有三种配置，off 关闭，console控制台，log 打印到日志；

  public static void main(String[] args) 

//        ConfigurableApplicationContext run = SpringApplication.run(ApplicationStart.class, args);
        SpringApplication springApplication = new SpringApplication();
        springApplication.setBannerMode(Banner.Mode.OFF);
        springApplication.addPrimarySources(Stream.of(ApplicationStart.class).collect(Collectors.toList()));
        springApplication.run(args);

    

使用图片充当banner

resources 目录下创建banner.jpg,  默认支持  "gif", "jpg", "png"  这几种格式 

源码分析

启动入口 springApplication.run 方法 > pringtBanner(environment)

private Banner printBanner(ConfigurableEnvironment environment) 
		if (this.bannerMode == Banner.Mode.OFF) 
			return null;
		
		ResourceLoader resourceLoader = (this.resourceLoader != null) ? this.resourceLoader
				: new DefaultResourceLoader(getClassLoader());
		// 使用SpringApplicationBannerPrinter 进行打印
		SpringApplicationBannerPrinter bannerPrinter = new SpringApplicationBannerPrinter(resourceLoader, this.banner);
		if (this.bannerMode == Mode.LOG) 
			return bannerPrinter.print(environment, this.mainApplicationClass, logger);
		
		return bannerPrinter.print(environment, this.mainApplicationClass, System.out);
	

bannerPrinter.print

	public Banner print(Environment environment, Class<?> sourceClass, Log logger) 
		Banner banner = getBanner(environment);
		try 
			logger.info(createStringFromBanner(banner, environment, sourceClass));
		
		catch (UnsupportedEncodingException ex) 
			logger.warn("Failed to create String for banner", ex);
		
		return new PrintedBanner(banner, sourceClass);
	

getBanner, 默认使用的是 SpringBootBanner

	private Banner getBanner(Environment environment) 
		Banners banners = new Banners();
		banners.addIfNotNull(getImageBanner(environment));
		banners.addIfNotNull(getTextBanner(environment));
		if (banners.hasAtLeastOneBanner()) 
			return banners;
		
		if (this.fallbackBanner != null) 
			return this.fallbackBanner;
		
		return DEFAULT_BANNER;
	

banner.printBanner(environment, sourceClass, out); 打印到控制台

Spring boot icon

在resources 目录下加入自己的favicon.ico 即可更改；springboot提供了这些静态资源路径都是可以的

“classpath:/META-INF/resources/”,“classpath:/resources/”, “classpath:/static/”, “classpath:/public/”

源码分析

重要类： WebMvcAutoConfiguration
这里就提现了 springboot 自动装配的特点
在WebMvcAutoConfiguration中找到 FaviconConfiguration静态内部类

@Configuration
		@ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
		public static class FaviconConfiguration implements ResourceLoaderAware 

			private final ResourceProperties resourceProperties;

			private ResourceLoader resourceLoader;

			public FaviconConfiguration(ResourceProperties resourceProperties) 
				this.resourceProperties = resourceProperties;
			

			@Override
			public void setResourceLoader(ResourceLoader resourceLoader) 
				this.resourceLoader = resourceLoader;
			

			@Bean
			public SimpleUrlHandlerMapping faviconHandlerMapping() 
				SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
				mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
				mapping.setUrlMap(Collections.singletonMap("**/favicon.ico", faviconRequestHandler()));
				return mapping;
			

			@Bean
			public ResourceHttpRequestHandler faviconRequestHandler() 
				ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler();
				requestHandler.setLocations(resolveFaviconLocations());
				return requestHandler;
			

			private List<Resource> resolveFaviconLocations() 
				String[] staticLocations = getResourceLocations(this.resourceProperties.getStaticLocations());
				List<Resource> locations = new ArrayList<>(staticLocations.length + 1);
				Arrays.stream(staticLocations).map(this.resourceLoader::getResource).forEach(locations::add);
				locations.add(new ClassPathResource("/"));
				return Collections.unmodifiableList(locations);
			

		

	

这里通过了SimpleUrlHandlerMapping 进行了路径的映射

下一节

下一节：Spring boot 配置文件和ymal结构