DispatcherServlet在启动时会根据配置文件创建HandlerMapping，这些HandlerMapping都实现了Ordered接口，DispatcherServlet实例化所有的HandlerMapping后放到一个集合中，并根据order对HandlerMapping进行排序。
DispatcherServlet在接受请求时会循环遍历有序的HandlerMapping集合，RequestMappingHandlerMapping的order是0，开始接收请求。
RequestMappingHandlerMappin继承AbstractHandlerMethodMapping，AbstractHandlerMethodMapping实现了InitializingBean，在实例化后对调用afterPropertiesSet方法，该方法完成method handler的注册：
Abstracthandlermethodmapping代码：
- public void afterPropertiesSet() {
- initHandlerMethods();
- }
-
- /**
- * Scan beans in the ApplicationContext, detect and register handler methods.
- * @see #isHandler(Class)
- * @see #getMappingForMethod(Method, Class)
- * @see #handlerMethodsInitialized(Map)
- */
- protected void initHandlerMethods() {
- if (logger.isDebugEnabled()) {
- logger.debug("Looking for request mappings in application context: " + getApplicationContext());
- }
-
- String[] beanNames = (this.detectHandlerMethodsInAncestorContexts ?
- BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
- getApplicationContext().getBeanNamesForType(Object.class));
-
- for (String beanName : beanNames) {
- if (isHandler(getApplicationContext().getType(beanName))){
- detectHandlerMethods(beanName);
- }
- }
- handlerMethodsInitialized(getHandlerMethods());
- }
RequestMappingHandlerMapping--Spring MVC优先级最高的HandlerMapping
原文：http://www.cnblogs.com/lishichang10/p/6389244.html
