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);

}