springMVC源码分析--AbstractHandlerMethodMapping注册url和HandlerMethod对应关系（十一）

在上一篇博客springMVC源码分析--AbstractHandlerMethodMapping获取url和HandlerMethod对应关系（十）中我们简单地介绍了获取url和HandlerMethod的过程，接下来我介绍一些url和HandlerMethod对应关系的注册过程。

在AbstractHandlerMethodMapping中当bean被注入到容器后会执行一系列的初始化过程，代码如下：

//容器启动时会运行此方法，完成handlerMethod的注册操作
	@Override
	public void afterPropertiesSet() {
		initHandlerMethods();
	}

进行HandlerMethod的注册操作，简单来说就是从springMVC的容器中获取所有的beanName，注册url和实现方法HandlerMethod的对应关系。

//handlerMethod的注册操作
	protected void initHandlerMethods() {
		if (logger.isDebugEnabled()) {
			logger.debug("Looking for request mappings in application context: " + getApplicationContext());
		}
		//从springMVC容器中获取所有的beanName
		String[] beanNames = (this.detectHandlerMethodsInAncestorContexts ?
				BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
				getApplicationContext().getBeanNamesForType(Object.class));
		//注册从容器中获取的beanName
		for (String name : beanNames) {
			if (!name.startsWith(SCOPED_TARGET_NAME_PREFIX) && isHandler(getApplicationContext().getType(name))) {
				detectHandlerMethods(name);
			}
		}
		handlerMethodsInitialized(getHandlerMethods());
	}

根据beanName进行一系列的注册，最终实现是在registerHandlerMethod

protected void detectHandlerMethods(final Object handler) {
		//获取bean实例
		Class<?> handlerType =
				(handler instanceof String ? getApplicationContext().getType((String) handler) : handler.getClass());

		// Avoid repeated calls to getMappingForMethod which would rebuild RequestMappingInfo instances
		final Map<Method, T> mappings = new IdentityHashMap<Method, T>();
		final Class<?> userType = ClassUtils.getUserClass(handlerType);

		Set<Method> methods = HandlerMethodSelector.selectMethods(userType, new MethodFilter() {
			@Override
			public boolean matches(Method method) {
				//创建RequestMappingInfo
				T mapping = getMappingForMethod(method, userType);
				if (mapping != null) {
					mappings.put(method, mapping);
					return true;
				}
				else {
					return false;
				}
			}
		});

		for (Method method : methods) {
			registerHandlerMethod(handler, method, mappings.get(method));
		}
	}

registerHandlerMethod的注册操作是将beanName，Method及创建的RequestMappingInfo之间的 关系。

//注册beanName和method及RequestMappingInfo之间的关系，RequestMappingInfo会保存url信息
	@Deprecated
	protected void registerHandlerMethod(Object handler, Method method, T mapping) {
		this.mappingRegistry.register(mapping, handler, method);
	}

getMappingForMethod方法是在子类RequestMappingHandlerMapping中实现的，具体实现就是创建一个RequestMappingInfo

@Override
	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;
	}

	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);
	}

这样就简单实现了将url和HandlerMethod的对应关系注册到mappingRegistry中。

MappingRegistry中的注册实现如下，并且MappingRegistry定义了几个map结构，用来存储注册信息

	private final Map<T, MappingRegistration<T>> registry = new HashMap<T, MappingRegistration<T>>();

		private final Map<T, HandlerMethod> mappingLookup = new LinkedHashMap<T, HandlerMethod>();

		private final MultiValueMap<String, T> urlLookup = new LinkedMultiValueMap<String, T>();

		private final Map<String, List<HandlerMethod>> nameLookup =
				new ConcurrentHashMap<String, List<HandlerMethod>>();

		private final Map<HandlerMethod, CorsConfiguration> corsLookup =
				new ConcurrentHashMap<HandlerMethod, CorsConfiguration>();

完成beanName，HandlerMethod及RequestMappingInfo之间的对应关系注册。

//注册beanName和method及RequestMappingInfo之间的关系，RequestMappingInfo中有url信息
		public void register(T mapping, Object handler, Method method) {

			this.readWriteLock.writeLock().lock();
			try {
				//创建HandlerMethod
				HandlerMethod handlerMethod = createHandlerMethod(handler, method);
				assertUniqueMethodMapping(handlerMethod, mapping);

				if (logger.isInfoEnabled()) {
					logger.info("Mapped \"" + mapping + "\" onto " + handlerMethod);
				}
				//保存url和handlerMethod之间的对应关系
				this.mappingLookup.put(mapping, handlerMethod);
				//保存url和RequestMappingInfo对应关系
				List<String> directUrls = getDirectUrls(mapping);
				for (String url : directUrls) {
					this.urlLookup.add(url, mapping);
				}

				String name = null;
				if (getNamingStrategy() != null) {
					name = getNamingStrategy().getName(handlerMethod, mapping);
					addMappingName(name, handlerMethod);
				}

				CorsConfiguration corsConfig = initCorsConfiguration(handler, method, mapping);
				if (corsConfig != null) {
					this.corsLookup.put(handlerMethod, corsConfig);
				}

				this.registry.put(mapping, new MappingRegistration<T>(mapping, handlerMethod, directUrls, name));
			}
			finally {
				this.readWriteLock.writeLock().unlock();
			}
		}