SpringFramework之@Controller/@RequestMapping解析

@Override
public void init() {
    registerBeanDefinitionParser("annotation-driven", new AnnotationDrivenBeanDefinitionParser());
    registerBeanDefinitionParser("default-servlet-handler", new DefaultServletHandlerBeanDefinitionParser());
    registerBeanDefinitionParser("interceptors", new InterceptorsBeanDefinitionParser());
    registerBeanDefinitionParser("resources", new ResourcesBeanDefinitionParser());
    registerBeanDefinitionParser("view-controller", new ViewControllerBeanDefinitionParser());
    registerBeanDefinitionParser("redirect-view-controller", new ViewControllerBeanDefinitionParser());
    registerBeanDefinitionParser("status-controller", new ViewControllerBeanDefinitionParser());
    registerBeanDefinitionParser("view-resolvers", new ViewResolversBeanDefinitionParser());
    registerBeanDefinitionParser("tiles-configurer", new TilesConfigurerBeanDefinitionParser());
    registerBeanDefinitionParser("freemarker-configurer", new FreeMarkerConfigurerBeanDefinitionParser());
    registerBeanDefinitionParser("groovy-configurer", new GroovyMarkupConfigurerBeanDefinitionParser());
    registerBeanDefinitionParser("script-template-configurer", new ScriptTemplateConfigurerBeanDefinitionParser());
    registerBeanDefinitionParser("cors", new CorsBeanDefinitionParser());
}

@Override
@Nullable
public BeanDefinition parse(Element element, ParserContext context) {
    ...
    RootBeanDefinition handlerMappingDef = new RootBeanDefinition(RequestMappingHandlerMapping.class);
    ...
    // Ensure BeanNameUrlHandlerMapping (SPR-8289) and default HandlerAdapters are not "turned off"
    MvcNamespaceUtils.registerDefaultComponents(context, source);
    return null;
}

@Override
public void afterPropertiesSet() {
	initHandlerMethods();
}

protected void initHandlerMethods() {
	if (logger.isDebugEnabled()) {
		logger.debug("Looking for request mappings in application context: " + getApplicationContext());
	}
	String[] beanNames = (this.detectHandlerMethodsInAncestorContexts ?
			BeanFactoryUtils.beanNamesForTypeIncludingAncestors(obtainApplicationContext(), Object.class) :
			obtainApplicationContext().getBeanNamesForType(Object.class));

	for (String beanName : beanNames) {
		if (!beanName.startsWith(SCOPED_TARGET_NAME_PREFIX)) {
			Class<?> beanType = null;
			try {
				beanType = obtainApplicationContext().getType(beanName);
			}
			catch (Throwable ex) {
				// An unresolvable bean type, probably from a lazy bean - let's ignore it.
				if (logger.isDebugEnabled()) {
					logger.debug("Could not resolve target class for bean with name '" + beanName + "'", ex);
				}
			}
			if (beanType != null && isHandler(beanType)) {
				detectHandlerMethods(beanName);
			}
		}
	}
	handlerMethodsInitialized(getHandlerMethods());
}

protected void detectHandlerMethods(Object handler) {
	Class<?> handlerType = (handler instanceof String ?
			obtainApplicationContext().getType((String) handler) : handler.getClass());

	if (handlerType != null) {
		Class<?> userType = ClassUtils.getUserClass(handlerType);
		Map<Method, T> methods = MethodIntrospector.selectMethods(userType,
				(MethodIntrospector.MetadataLookup<T>) method -> {
					try {
						return getMappingForMethod(method, userType);
					}
					catch (Throwable ex) {
						throw new IllegalStateException("Invalid mapping on handler class [" +
								userType.getName() + "]: " + method, ex);
					}
				});
		if (logger.isDebugEnabled()) {
			logger.debug(methods.size() + " request handler methods found on " + userType + ": " + methods);
		}
		methods.forEach((method, mapping) -> {
			Method invocableMethod = AopUtils.selectInvocableMethod(method, userType);
			registerHandlerMethod(handler, invocableMethod, mapping);
		});
	}
}

@Override
@Nullable
protected RequestMappingInfo getMappingForMethod(Method method, Class<?> handlerType) {
	RequestMappingInfo info = createRequestMappingInfo(method);
	if (info != null) {
		RequestMappingInfo typeInfo = createRequestMappingInfo(handlerType);
		if (typeInfo != null) {
			info = typeInfo.combine(info);
		}
	}
	return info;
}

@Nullable
private RequestMappingInfo createRequestMappingInfo(AnnotatedElement element) {
	RequestMapping requestMapping = AnnotatedElementUtils.findMergedAnnotation(element, RequestMapping.class);
	RequestCondition<?> condition = (element instanceof Class ?
			getCustomTypeCondition((Class<?>) element) : getCustomMethodCondition((Method) element));
	return (requestMapping != null ? createRequestMappingInfo(requestMapping, condition) : null);
}

protected RequestMappingInfo createRequestMappingInfo(
		RequestMapping requestMapping, @Nullable RequestCondition<?> customCondition) {

	RequestMappingInfo.Builder builder = RequestMappingInfo
			.paths(resolveEmbeddedValuesInPatterns(requestMapping.path()))
			.methods(requestMapping.method())
			.params(requestMapping.params())
			.headers(requestMapping.headers())
			.consumes(requestMapping.consumes())
			.produces(requestMapping.produces())
			.mappingName(requestMapping.name());
	if (customCondition != null) {
		builder.customCondition(customCondition);
	}
	return builder.options(this.config).build();
}

@Bean
public RequestMappingHandlerMapping requestMappingHandlerMapping() {
	RequestMappingHandlerMapping mapping = createRequestMappingHandlerMapping();
...