springboot核心注解

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = { @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
		@Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication {
	......
}

private static Map<String, List<String>> loadSpringFactories(ClassLoader classLoader) {
	Map<String, List<String>> result = (Map)cache.get(classLoader);
	if (result != null) {
		return result;
	} else {
		HashMap result = new HashMap();
		try {
			Enumeration urls = classLoader.getResources("META-INF/spring.factories");
			while(urls.hasMoreElements()) {
				URL url = (URL)urls.nextElement();
				UrlResource resource = new UrlResource(url);
				Properties properties = PropertiesLoaderUtils.loadProperties(resource);
				Iterator var6 = properties.entrySet().iterator();
				while(var6.hasNext()) {
					Entry<?, ?> entry = (Entry)var6.next();
					String factoryTypeName = ((String)entry.getKey()).trim();
					String[] factoryImplementationNames = 
								StringUtils.commaDelimitedListToStringArray((String)entry.getValue());
					String[] var10 = factoryImplementationNames;
					int var11 = factoryImplementationNames.length;

					for(int var12 = 0; var12 < var11; ++var12) {
						String factoryImplementationName = var10[var12];
						((List)result.computeIfAbsent(factoryTypeName, (key) -> {
							return new ArrayList();
						})).add(factoryImplementationName.trim());
					}
				}
			}
			result.replaceAll((factoryType, implementations) -> {
				return (List)implementations.stream().distinct().
						collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
			});
			cache.put(classLoader, result);
			return result;
		} catch (IOException var14) {
			throw new IllegalArgumentException("Unable to load factories from location [META-INF/spring.factories]", var14);
		}
	}
}