Springboot启动流程分析-4——run方法之prepareEnvironment、configureIgnoreBeanInfo、printBanner

上一篇文章大概介绍了springboot启动过程中的run方法的概览。介绍了计时器、监听器等。
本文主要分析三个操作。分别是
prepareEnvironment 运行环境的准备工作
configureIgnoreBeanInfo配置忽略BeanInfo
printBanner打印出banner

#1.prepareEnvironment

private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
			ApplicationArguments applicationArguments) {
   
		// Create and configure the environment
		ConfigurableEnvironment environment = getOrCreateEnvironment();
		configureEnvironment(environment, applicationArguments.getSourceArgs());
		ConfigurationPropertySources.attach(environment);
		listeners.environmentPrepared(environment);
		bindToSpringApplication(environment);
		if (!this.isCustomEnvironment) {
   
			environment = new EnvironmentConverter(getClassLoader()).convertEnvironmentIfNecessary(environment,
					deduceEnvironmentClass());
		}
		ConfigurationPropertySources.attach(environment);
		return environment;
	}

#1-1.创建或获取一个新的运行环境getOrCreateEnvironment()

private ConfigurableEnvironment getOrCreateEnvironment() {
   
		if (this.environment != null) {
   
			return this.environment;
		}
		switch (this.webApplicationType) {
   
		case SERVLET:
			return new StandardServletEnvironment();
		case REACTIVE:
			return new StandardReactiveWebEnvironment();
		default:
			return new StandardEnvironment();
		}
	}

因为在之前创建SpringApplication实例时候就有判断当前应用是 SERVLET 类型
所以会创建一个标准SERVLET运行环境 StandardServletEnvironment
创建后的运行环境如下

1-2.配置运行环境configureEnvironment

/**
	 * Template method delegating to
	 * {@link #configurePropertySources(ConfigurableEnvironment, String[])} and
	 * {@link #configureProfiles(ConfigurableEnvironment, String[])} in that order.
	 * Override this method for complete control over Environment customization, or one of
	 * the above for fine-grained control over property sources or profiles, respectively.
	 * @param environment this application's environment
	 * @param args arguments passed to the {@code run} method
	 * @see #configureProfiles(ConfigurableEnvironment, String[])
	 * @see #configurePropertySources(ConfigurableEnvironment, String[])
	 */
	protected void configureEnvironment(ConfigurableEnvironment environment, String[] args) {
   
		if (this.addConversionService) {
   
			ConversionService conversionService = ApplicationConversionService.getSharedInstance();
			environment.setConversionService((ConfigurableConversionService) conversionService);
		}
		configurePropertySources(environment, args);
		configureProfiles(environment, args);
	}

ConversionService主要用于类型转换 注释说明如下

A service interface for type conversion. This is the entry point into the convert system.

#1-2-1.configurePropertySources

/**
	 * Add, remove or re-order any {@link PropertySource}s in this application's
	 * environment.
	 * @param environment this application's environment
	 * @param args arguments passed to the {@code run} method
	 * @see #configureEnvironment(ConfigurableEnvironment, String[])
	 */
	protected void configurePropertySources(ConfigurableEnvironment environment, String[] args) {
   
		MutablePropertySources sources = environment.getPropertySources();
		if (this.defaultProperties != null && !this.defaultProperties.isEmpty()) {
   
			sources.addLast(new MapPropertySource("defaultProperties", this.defaultProperties));
		}
		if (this.addCommandLineProperties && args.length > 0) {
   
			String name = CommandLinePropertySource.COMMAND_LINE_PROPERTY_SOURCE_NAME;
			if (sources.contains(name)) {
   
				PropertySource<?> source = sources.get(name);
				CompositePropertySource composite = new CompositePropertySource(name);
				composite.addPropertySource(
						new SimpleCommandLinePropertySource("springApplicationCommandLineArgs", args));
				composite.addPropertySource(source);
				sources.replace(name, composite);
			}
			else {
   
				sources.addFirst(new SimpleCommandLinePropertySource(args));
			}
		}
	}

#1-2-2.configureProfiles

/**
	 * Configure which profiles are active (or active by default) for this application
	 * environment. Additional profiles may be activated during configuration file
	 * processing via the {@code spring.profiles.active} property.
	 * @param environment this application's environment
	 * @param args arguments passed to the {@code run} method
	 * @see #configureEnvironment(ConfigurableEnvironment, String[])
	 * @see org.springframework.boot.context.config.ConfigFileApplicationListener
	 */
	protected void configureProfiles(ConfigurableEnvironment environment, String[] args) {
   
		Set<String> profiles = new LinkedHashSet<>(this.additionalProfiles);
		profiles.addAll(Arrays.asList(environment.getActiveProfiles()));
		environment.setActiveProfiles(StringUtils.toStringArray(profiles))