springMVC源码分析--AbstractDetectingUrlHandlerMapping（五）

上一篇博客springMVC源码分析--AbstractUrlHandlerMapping（三）中我们介绍了AbstractUrlHandlerMapping，主要介绍了一个handlerMap的url和Handler的关系存取的过程。

在上一博客中我们介绍了handlerMap有一个注册url和Handler关系的注册函数，这个函数的调用是在实现类AbstractDetectingUrlHandlerMapping中实现的，目的是springMVC容器启动时将url和handler的对应关系注册到handlerMap中。

AbstractDetectingUrlHandlerMapping 抽象类：通过重写initApplicationContext来注册Handler，调用detectHandlers方法会根据配置的detectHand-lersInAcestorContexts参数从springMVC容器或者springMVC集群父容器中找到所有bean的beanName，然后调用determineUrlsForHandler方法对每个

beanName解析出对应的urls，如果解析的结果不为空，则将解析出的urls和beanName注册到父类的map中。

//初始化容器
	@Override
	public void initApplicationContext() throws ApplicationContextException {
		super.initApplicationContext();
		detectHandlers();
	}

在调用父类的super.initApplicationContext后就是注册每个bean和url的关系，调用detectHandlers

//注册每个bean对应的url的关系
	protected void detectHandlers() throws BeansException {
		if (logger.isDebugEnabled()) {
			logger.debug("Looking for URL mappings in application context: " + getApplicationContext());
		}
		//获取容器的所有bean的名字
		String[] beanNames = (this.detectHandlersInAncestorContexts ?
				BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
				getApplicationContext().getBeanNamesForType(Object.class));

		// Take any bean name that we can determine URLs for.
		//对每个beanName解析url，如果能解析到就注册到父类的map中
		for (String beanName : beanNames) {
			//子类具体去实现
			String[] urls = determineUrlsForHandler(beanName);
			if (!ObjectUtils.isEmpty(urls)) {
				// URL paths found: Let's consider it a handler.
				//将解析的url注册到父类
				registerHandler(urls, beanName);
			}
			else {
				if (logger.isDebugEnabled()) {
					logger.debug("Rejected bean name '" + beanName + "': no URL paths identified");
				}
			}
		}
	}

其中determineUrlsForHandler函数是在其子类中实现的，registerHandler函数操作是在父类AbstractUrlHandlerMapping中实现的，将bean和url的关系注册到handlerMap中。

AbstractDetectingUrlHandlerMapping的完整源码如下：

public abstract class AbstractDetectingUrlHandlerMapping extends AbstractUrlHandlerMapping {

	private boolean detectHandlersInAncestorContexts = false;

	public void setDetectHandlersInAncestorContexts(boolean detectHandlersInAncestorContexts) {
		this.detectHandlersInAncestorContexts = detectHandlersInAncestorContexts;
	}

	//初始化容器
	@Override
	public void initApplicationContext() throws ApplicationContextException {
		super.initApplicationContext();
		detectHandlers();
	}

	//注册每个bean对应的url的关系
	protected void detectHandlers() throws BeansException {
		if (logger.isDebugEnabled()) {
			logger.debug("Looking for URL mappings in application context: " + getApplicationContext());
		}
		//获取容器的所有bean的名字
		String[] beanNames = (this.detectHandlersInAncestorContexts ?
				BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
				getApplicationContext().getBeanNamesForType(Object.class));

		// Take any bean name that we can determine URLs for.
		//对每个beanName解析url，如果能解析到就注册到父类的map中
		for (String beanName : beanNames) {
			//子类具体去实现
			String[] urls = determineUrlsForHandler(beanName);
			if (!ObjectUtils.isEmpty(urls)) {
				// URL paths found: Let's consider it a handler.
				//将解析的url注册到父类
				registerHandler(urls, beanName);
			}
			else {
				if (logger.isDebugEnabled()) {
					logger.debug("Rejected bean name '" + beanName + "': no URL paths identified");
				}
			}
		}
	}
	//抽象方法，子类中实现
	protected abstract String[] determineUrlsForHandler(String beanName);

}