SpringApplication到底run了什么（上）

public ConfigurableApplicationContext run(String... args) {
	StopWatch stopWatch = new StopWatch();
	stopWatch.start();
	ConfigurableApplicationContext context = null;
	Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>();
	configureHeadlessProperty();
	SpringApplicationRunListeners listeners = getRunListeners(args);
	listeners.starting();
	try {
		ApplicationArguments applicationArguments = new DefaultApplicationArguments(
				args);
		ConfigurableEnvironment environment = prepareEnvironment(listeners,
				applicationArguments);
		//后面还有，本篇文章就解析到这。。。。
}

public void starting() {
    this.initialMulticaster.multicastEvent(
            new ApplicationStartingEvent(this.application, this.args));
}

public void multicastEvent(final ApplicationEvent event, @Nullable ResolvableType eventType) {
        ResolvableType type = (eventType != null ? eventType : resolveDefaultEventType(event));
        for (final ApplicationListener<?> listener : getApplicationListeners(event, type)) {
            Executor executor = getTaskExecutor();
            if (executor != null) {
                executor.execute(() -> invokeListener(listener, event));
            }
            else {
                invokeListener(listener, event);
            }
        }
    }

private ConfigurableEnvironment prepareEnvironment(
		SpringApplicationRunListeners listeners,
		ApplicationArguments applicationArguments) {
	ConfigurableEnvironment environment = getOrCreateEnvironment();
	configureEnvironment(environment, applicationArguments.getSourceArgs());
	listeners.environmentPrepared(environment);
	if (!this.webEnvironment) {
		environment = new EnvironmentConverter(getClassLoader())
				.convertToStandardEnvironmentIfNecessary(environment);
	}
	return environment;
}

private ConfigurableEnvironment getOrCreateEnvironment() {
	if (this.environment != null) {
		return this.environment;
	}
	if (this.webApplicationType == WebApplicationType.SERVLET) {
		return new StandardServletEnvironment();
	}
	return new StandardEnvironment();
}

protected void customizePropertySources(MutablePropertySources propertySources) {
	propertySources.addLast(new StubPropertySource("servletConfigInitParams"));
	propertySources.addLast(new StubPropertySource("servletContextInitParams"));
	if (JndiLocatorDelegate.isDefaultJndiEnvironmentAvailable()) {
		propertySources.addLast(new JndiPropertySource("jndiProperties"));
	}
	super.customizePropertySources(propertySources);
}
 //这是它父类的
protected void customizePropertySources(MutablePropertySources propertySources) {
	propertySources.addLast(new MapPropertySource("systemProperties", getSystemProperties()));
	propertySources.addLast(new SystemEnvironmentPropertySource("systemEnvironment", getSystemEnvironment()));
}

protected void configureEnvironment(ConfigurableEnvironment environment,
    String[] args) {
    // 配置PropertySources
    configurePropertySources(environment, args);
    // 配置Profiles
    configureProfiles(environment, args);
}

protected void configurePropertySources(ConfigurableEnvironment environment,
        String[] args) {
    MutablePropertySources sources = environment.getPropertySources();
    if (this.defaultProperties != null && !this.defaultProperties.isEmpty()) {
        // 存在默认配置将其放到最后位置
        sources.addLast(
                new MapPropertySource("defaultProperties", this.defaultProperties));
    }
    // 如果存在命令行参数则将原有的替换掉
    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 {
            // 将其放到第一位置
            sources.addFirst(new SimpleCommandLinePropertySource(args));
        }
    }
}

protected void configureProfiles(ConfigurableEnvironment environment, String[] args) {
    environment.getActiveProfiles();
    Set<String> profiles = new LinkedHashSet<>(this.additionalProfiles);
    profiles.addAll(Arrays.asList(environment.getActiveProfiles()));
    environment.setActiveProfiles(StringUtils.toStringArray(profiles));
}

protected void bindToSpringApplication(ConfigurableEnvironment environment) {
		try {
			Binder.get(environment).bind("spring.main", Bindable.ofInstance(this));
		}
		catch (Exception ex) {
			throw new IllegalStateException("Cannot bind to SpringApplication", ex);
		}
	}

public static void attach(Environment environment) {
		Assert.isInstanceOf(ConfigurableEnvironment.class, environment);
		MutablePropertySources sources = ((ConfigurableEnvironment) environment)
				.getPropertySources();
		PropertySource<?> attached = sources.get("configurationProperties");
		if (attached != null && attached.getSource() != sources) {
			sources.remove("configurationProperties");
			attached = null;
		}
		if (attached == null) {
			sources.addFirst(new ConfigurationPropertySourcesPropertySource(
					"configurationProperties",
					new SpringConfigurationPropertySources(sources)));
		}
	}