SpringBoot源码系列（1）--SpringApplication

1、指定当前应用类型为servlet,分为reactive/servlet/none三种

this.webApplicationType = WebApplicationType.deduceFromClasspath();

2、从spring.factories文件中加载key值为ApplicationContextInitializer的7个initializer

setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));

3、从spring.factories文件中加载key值为ApplicationListener的11个listener

setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));

4、根据堆栈信息找到main方法与当前springApplication类

    private Class deduceMainApplicationClass() {
		try {
			StackTraceElement[] stackTrace = new RuntimeException().getStackTrace();
			for (StackTraceElement stackTraceElement : stackTrace) {
				if ("main".equals(stackTraceElement.getMethodName())) {
					return Class.forName(stackTraceElement.getClassName());
				}
			}
		}
		catch (ClassNotFoundException ex) {
			// Swallow and continue
		}
		return null;
	}