Spring boot Banner和icon

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