前言
上一篇文章dispatcherservlet初始化中提到，如果没有配置handlermapping就会采取默认的策略进行配置handlermapping，这篇文章就要讲述mvc:annotation-driven对默认策略的改变。它背后到底注册了哪些HandlerMapping和HandlerAdapter。
1. 配置mvc:annotation-driven
在dispatcherservlet对应的配置文件上有这样一段配置
???<mvc:annotation-driven /> ???????<aop:aspectj-autoproxy proxy-target-class="true"/> ???????<mvc:interceptors> ???????<ref bean="performanceLogInterceptor"></ref> ???????<ref bean="concurrentCtrlInterceptor"></ref> ???????<ref bean="authenticationInterceptor"></ref> ???????<ref bean="authorityInterceptor"></ref> ???????<ref bean="tpsControlInterceptor"></ref> ????</mvc:interceptors>
开启了<mvc:annotation-driven/>，然后我们会找到这样的一个实现类AnnotationDrivenBeanDefinitionParser解析处理这个标签
/**
*这里清清楚楚写着该类是专门处理 <mvc:annotation-driven/>标签的
* A {@link BeanDefinitionParser} that provides the configuration for the * {@code <annotation-driven/>} MVC namespace element
*
*这里说明了注册的HandlerMapping * <p>This class registers the following {@link HandlerMapping}s:</p> * <ul> * <li>{@link RequestMappingHandlerMapping} * ordered at 0 for mapping requests to annotated controller methods. * <li>{@link BeanNameUrlHandlerMapping} * ordered at 2 to map URL paths to controller bean names. * </ul>…… */class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser { ??……}
我们来看看mvc:annotation-driven都注册了哪些东西
???@Override ???public BeanDefinition parse(Element element, ParserContext parserContext) { ???????Object source = parserContext.extractSource(element); ???????XmlReaderContext readerContext = parserContext.getReaderContext(); ???????RootBeanDefinition handlerMappingDef = new RootBeanDefinition(RequestMappingHandlerMapping.class); ???????ManagedList<?> messageConverters = getMessageConverters(element, source, parserContext); ???????RootBeanDefinition handlerAdapterDef = new RootBeanDefinition(RequestMappingHandlerAdapter.class); ?????????????????…… ???????RootBeanDefinition exceptionHandlerExceptionResolver = new RootBeanDefinition(ExceptionHandlerExceptionResolver.class); ?????????????RootBeanDefinition responseStatusExceptionResolver = new RootBeanDefinition(ResponseStatusExceptionResolver.class); ???????????????RootBeanDefinition defaultExceptionResolver = new RootBeanDefinition(DefaultHandlerExceptionResolver.class); ??// Ensure BeanNameUrlHandlerMapping (SPR-8289) and default HandlerAdapters are not "turned off" ???????MvcNamespaceUtils.registerDefaultComponents(parserContext, source); ???????parserContext.popAndRegisterContainingComponent(); ???????return null; ???}MvcNamespaceUtils.registerDefaultComponents的内容如下：
public static void registerDefaultComponents(ParserContext parserContext, Object source) { ???????registerBeanNameUrlHandlerMapping(parserContext, source); ???????registerHttpRequestHandlerAdapter(parserContext, source); ???????registerSimpleControllerHandlerAdapter(parserContext, source); ???}至此所注册的HandlerMapping和HandlerAdapter我们都找到了。
<mvc:annotation-driven>注册了什么
原文地址：https://www.cnblogs.com/whx7762/p/8118655.html