SpringMVC源码-AbstractUrlHandlerMapping处理器映射器将实现Controller接口的方式定义的路径存储进去

DispatcherServlet的initStrategies方法用来初始化SpringMVC的九大内置组件
initStrategies

protected void initStrategies(ApplicationContext context) {
// 初始化 MultipartResolver:主要用来处理文件上传.如果定义过当前类型的bean对象，那么直接获取，如果没有的话，可以为null
initMultipartResolver(context);
// 初始化 LocaleResolver:主要用来处理国际化配置,基于URL参数的配置(AcceptHeaderLocaleResolver)，基于session的配置(SessionLocaleResolver)，基于cookie的配置(CookieLocaleResolver)
initLocaleResolver(context);
// 初始化 ThemeResolver:主要用来设置主题Theme
initThemeResolver(context);
// 初始化 HandlerMapping:映射器，用来将对应的request跟controller进行对应
initHandlerMappings(context);
// 初始化 HandlerAdapter:处理适配器，主要包含Http请求处理器适配器，简单控制器处理器适配器，注解方法处理器适配器
initHandlerAdapters(context);
// 初始化 HandlerExceptionResolver:基于HandlerExceptionResolver接口的异常处理
initHandlerExceptionResolvers(context);
// 初始化 RequestToViewNameTranslator:当controller处理器方法没有返回一个View对象或逻辑视图名称，并且在该方法中没有直接往response的输出流里面写数据的时候，spring将会采用约定好的方式提供一个逻辑视图名称
initRequestToViewNameTranslator(context);
// 初始化 ViewResolver: 将ModelAndView选择合适的视图进行渲染的处理器
initViewResolvers(context);
// 初始化 FlashMapManager: 提供请求存储属性，可供其他请求使用
initFlashMapManager(context);
}

initHandlerMappings初始化 HandlerMapping:映射器，用来将对应的request跟controller进行对应，该方法是在构造SpringMVC容器调用的。
调用链路如下:

ApplicationObjectSupport实现了ApplicationContextAware接口，所以会调用setApplicationContext:78, ApplicationObjectSupport (org.springframework.context.support)
invokeAwareInterfaces:146, ApplicationContextAwareProcessor (org.springframework.context.support)
postProcessBeforeInitialization:118, ApplicationContextAwareProcessor (org.springframework.context.support)
applyBeanPostProcessorsBeforeInitialization:497, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
完成实例化、属性填充之后进行初始化调用bpp的方法——initializeBean:2256, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
doCreateBean:736, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
createBean:630, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
createBean:361, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
createDefaultStrategy:957, DispatcherServlet (org.springframework.web.servlet)
获得默认配置的handlerMapping类——getDefaultStrategies:925, DispatcherServlet (org.springframework.web.servlet)
initHandlerMappings:657, DispatcherServlet (org.springframework.web.servlet)
initStrategies:529, DispatcherServlet (org.springframework.web.servlet)
onRefresh:514, DispatcherServlet (org.springframework.web.servlet)
onApplicationEvent:901, FrameworkServlet (org.springframework.web.servlet)
onApplicationEvent:1277, FrameworkServlet$ContextRefreshListener (org.springframework.web.servlet)
onApplicationEvent:1273, FrameworkServlet$ContextRefreshListener (org.springframework.web.servlet)
onApplicationEvent:64, GenericApplicationListenerAdapter (org.springframework.context.event)
onApplicationEventInternal:109, SourceFilteringListener (org.springframework.context.event)
onApplicationEvent:73, SourceFilteringListener (org.springframework.context.event)
doInvokeListener:215, SimpleApplicationEventMulticaster (org.springframework.context.event)
invokeListener:202, SimpleApplicationEventMulticaster (org.springframework.context.event)
multicastEvent:164, SimpleApplicationEventMulticaster (org.springframework.context.event)
publishEvent:440, AbstractApplicationContext (org.springframework.context.support)
publishEvent:379, AbstractApplicationContext (org.springframework.context.support)
finishRefresh:1053, AbstractApplicationContext (org.springframework.context.support)
refresh:618, AbstractApplicationContext (org.springframework.context.support)
configureAndRefreshWebApplicationContext:759, FrameworkServlet (org.springframework.web.servlet)
createWebApplicationContext:715, FrameworkServlet (org.springframework.web.servlet)
createWebApplicationContext:773, FrameworkServlet (org.springframework.web.servlet)
initWebApplicationContext:625, FrameworkServlet (org.springframework.web.servlet)
initServletBean:536, FrameworkServlet (org.springframework.web.servlet)
init:185, HttpServletBean (org.springframework.web.servlet)
init:158, GenericServlet (javax.servlet)
initServlet:1164, StandardWrapper (org.apache.catalina.core)
loadServlet:1117, StandardWrapper (org.apache.catalina.core)
load:1010, StandardWrapper (org.apache.catalina.core)
loadOnStartup:4957, StandardContext (org.apache.catalina.core)
startInternal:5264, StandardContext (org.apache.catalina.core)
start:183, LifecycleBase (org.apache.catalina.util)
addChildInternal:726, ContainerBase (org.apache.catalina.core)
addChild:698, ContainerBase (org.apache.catalina.core)
addChild:696, StandardHost (org.apache.catalina.core)
manageApp:1783, HostConfig (org.apache.catalina.startup)
invoke0:-1, NativeMethodAccessorImpl (sun.reflect)
invoke:62, NativeMethodAccessorImpl (sun.reflect)
invoke:43, DelegatingMethodAccessorImpl (sun.reflect)
invoke:498, Method (java.lang.reflect)
invoke:293, BaseModelMBean (org.apache.tomcat.util.modeler)
invoke:819, DefaultMBeanServerInterceptor (com.sun.jmx.interceptor)
invoke:801, JmxMBeanServer (com.sun.jmx.mbeanserver)
createStandardContext:460, MBeanFactory (org.apache.catalina.mbeans)
createStandardContext:408, MBeanFactory (org.apache.catalina.mbeans)
invoke0:-1, NativeMethodAccessorImpl (sun.reflect)
invoke:62, NativeMethodAccessorImpl (sun.reflect)
invoke:43, DelegatingMethodAccessorImpl (sun.reflect)
invoke:498, Method (java.lang.reflect)
invoke:293, BaseModelMBean (org.apache.tomcat.util.modeler)
invoke:819, DefaultMBeanServerInterceptor (com.sun.jmx.interceptor)
invoke:801, JmxMBeanServer (com.sun.jmx.mbeanserver)
invoke:468, MBeanServerAccessController (com.sun.jmx.remote.security)
doOperation:1468, RMIConnectionImpl (javax.management.remote.rmi)
access$300:76, RMIConnectionImpl (javax.management.remote.rmi)
run:1309, RMIConnectionImpl$PrivilegedOperation (javax.management.remote.rmi)
doPrivileged:-1, AccessController (java.security)
doPrivilegedOperation:1408, RMIConnectionImpl (javax.management.remote.rmi)
invoke:829, RMIConnectionImpl (javax.management.remote.rmi)
invoke0:-1, NativeMethodAccessorImpl (sun.reflect)
invoke:62, NativeMethodAccessorImpl (sun.reflect)
invoke:43, DelegatingMethodAccessorImpl (sun.reflect)
invoke:498, Method (java.lang.reflect)
dispatch:346, UnicastServerRef (sun.rmi.server)
run:200, Transport$1 (sun.rmi.transport)
run:197, Transport$1 (sun.rmi.transport)
doPrivileged:-1, AccessController (java.security)
serviceCall:196, Transport (sun.rmi.transport)
handleMessages:568, TCPTransport (sun.rmi.transport.tcp)
run0:826, TCPTransport$ConnectionHandler (sun.rmi.transport.tcp)
lambda$run$0:683, TCPTransport$ConnectionHandler (sun.rmi.transport.tcp)
run:-1, 1637217430 (sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda$26)
doPrivileged:-1, AccessController (java.security)
run:682, TCPTransport$ConnectionHandler (sun.rmi.transport.tcp)
runWorker:1142, ThreadPoolExecutor (java.util.concurrent)
run:617, ThreadPoolExecutor$Worker (java.util.concurrent)
run:748, Thread (java.lang)

ApplicationObjectSupport等相关类继承关系

ApplicationObjectSupport实现了ApplicationContextAware接口，setApplicationContext方法里调用initApplicationContext(context);

经这一步一直调用到:
AbstractHandlerMapping的initApplicationContext方法:

/**初始化拦截器
 * Initializes the interceptors.
 * @see #extendInterceptors(java.util.List)
 * @see #initInterceptors()
 */
@Override
protected void initApplicationContext() throws BeansException {
// 空实现，交给子类实现，用于注册自定义的拦截器到interceptors中，目前暂无子类实现
extendInterceptors(this.interceptors);
// 扫描已注册的MappedInterceptor的Bean们，添加到adaptedInterceptors中
detectMappedInterceptors(this.adaptedInterceptors);
// 将interceptors初始化成 HandlerInterceptor类型，添加到adaptedInterceptors中
initInterceptors();
}

detectMappedInterceptors执行:

SpringMVC的配置文件applicationContext.xml有定义拦截器:

    <mvc:interceptors>
    <bean class="com.mashibing.interceptor.HandlerMappingInterceptor"/>
    </mvc:interceptors>

将配置文件中配置的拦截器生成放在mappedInterceptors中。
initInterceptors执行，interceptors为空，跳过执行。

/**
 * 初始化interceptors,并适配HandlerInterceptors和WebRequestInterceptor
 *
 * Initialize the specified interceptors adapting
 * {@link WebRequestInterceptor}s to {@link HandlerInterceptor}.
 * @see #setInterceptors
 * @see #adaptInterceptor
 */
protected void initInterceptors() {
if (!this.interceptors.isEmpty()) {
for (int i = 0; i < this.interceptors.size(); i++) {
Object interceptor = this.interceptors.get(i);
if (interceptor == null) {
throw new IllegalArgumentException("Entry number " + i + " in interceptors array is null");
}
// 将interceptors初始化成HandlerInterceptor类型，添加到adaptedInterceptors中
// 注意，HandlerInterceptor无需进行路径匹配，直接拦截全部
this.adaptedInterceptors.add(adaptInterceptor(interceptor));
}
}
}

AbstractDetectingUrlHandlerMapping的initApplicationContext中方法detectHandlers开始执行:
AbstractDetectingUrlHandlerMapping类的detectHandlers方法开始执行:

/**
 * 根据配置的detectHandlersInAncestorContexts参数从springmvc容器或者父容器中找到所有bean的beanName，然后使用determineUrlsForHandler方法
 * 对每个beanName解析出对应的urls，如果解析结果不为空，则解析出urls和beanName注册到父类的map中，
 *
 * Register all handlers found in the current ApplicationContext.
 * <p>The actual URL determination for a handler is up to the concrete
 * {@link #determineUrlsForHandler(String)} implementation. A bean for
 * which no such URLs could be determined is simply not considered a handler.
 * @throws org.springframework.beans.BeansException if the handler couldn't be registered
 * @see #determineUrlsForHandler(String)
 */
protected void detectHandlers() throws BeansException {
// 从spring上下文获取所有Object类型的bean名称
ApplicationContext applicationContext = obtainApplicationContext();//获取的是springmvc的容器
// 获取容器中所有bean的名字
String[] beanNames = (this.detectHandlersInAncestorContexts ?
BeanFactoryUtils.beanNamesForTypeIncludingAncestors(applicationContext, Object.class) :
applicationContext.getBeanNamesForType(Object.class));

// Take any bean name that we can determine URLs for.
// 对每一个beanName解析url，如果能解析到就注册到父类的map中
for (String beanName : beanNames) {
// 使用beanName解析url，模板方法，有子类实现 检查给定bean的名称和别名，查找以“”开头的url。
String[] urls = determineUrlsForHandler(beanName);
// 如果该bean存在对应的url，则添加该处理器
if (!ObjectUtils.isEmpty(urls)) {
// URL paths found: Let's consider it a handler.
// 调用父类的方法，往handlerMap中添加注册器
registerHandler(urls, beanName);
}
}

if ((logger.isDebugEnabled() && !getHandlerMap().isEmpty()) || logger.isTraceEnabled()) {
logger.debug("Detected " + getHandlerMap().size() + " mappings in " + formatMappingName());
}
}

beanNames 是SpringMVC容器的所有对象的名称:使用beanName解析url，模板方法，有子类实现 检查给定bean的名称和别名，查找以“/”开头的url。调用父类的方法，往handlerMap中添加注册器
applicationContext.xml文件定义的bean是以/开头的，会被放到handlerMap

    <bean name="/test01" class="com.mashibing.controller.testController.Test01"></bean>
    <bean id="/test02" class="com.mashibing.controller.testController.Test02"></bean>

最终放到AbstractUrlHandlerMapping的handlerMap中

原文地址：https://blog.csdn.net/qq_37200262/article/details/142653470

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