最近在调试项目时,debug DispatcherServlet时,发现handlerMappings属性包含了RequestMappingHandlerMapping、SimpleUrlHandlerMapping、BeanNameUrlHandlerMapping。
可是我明明只声明了
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"></bean>
真是百思不得解啊,因为是旧项目基础改造的,以为是别的地方有隐秘用法,找了半天,没找到,今天下班时,突然想到我注册了
<mvc:resources location="" mapping=""/>
翻看ResourcesBeanDefinitionParser,查到了关键代码:
1.
RootBeanDefinition handlerMappingDef = new RootBeanDefinition(SimpleUrlHandlerMapping.class);
handlerMappingDef.setSource(source);
handlerMappingDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
handlerMappingDef.getPropertyValues().add("urlMap", urlMap);
2.
// Ensure BeanNameUrlHandlerMapping (SPR-8289) and default HandlerAdapters are not "turned off"
// Register HttpRequestHandlerAdapter
MvcNamespaceUtils.registerDefaultComponents(parserContext, source);
指向
public static void registerDefaultComponents(ParserContext parserContext, Object source) {
registerBeanNameUrlHandlerMapping(parserContext, source);
registerHttpRequestHandlerAdapter(parserContext, source);
registerSimpleControllerHandlerAdapter(parserContext, source);
}
才知道原因了。呵呵。