spring MVC源码探索之AbstractHandlerMethodMapping

AbstractHandlerMethodMapping 是什么

官方解释是这样的。

/**
 * Abstract base class for {@link HandlerMapping} implementations that define
 * a mapping between a request and a {@link HandlerMethod}.
 *
 * 
For each registered handler method, a unique mapping is maintained with
 * subclasses defining the details of the mapping type {@code }.
 * @param  The mapping for a {@link HandlerMethod} containing the conditions
 * needed to match the handler method to incoming request.
 */
public abstract class AbstractHandlerMethodMapping extends AbstractHandlerMapping implements InitializingBean 
 

我的理解为AbstractHandlerMethodMapping为每个注册的handler method，对于每个子类映射类型都维护着其唯一的一个映射，就是维护handler method 和URL的关系。主要用于@Controller,@RequestMapping 等注解

AbstractHandlerMethodMapping 实现了InitializingBean接口，InitializingBean是在程序启动的时候执行其唯一的afterPropertiesSet()方法，那我们就先看一下启动时候的要做哪些操作。

initHandlerMethods()

/**
      在初始化的时候发现 handler methods
    * Detects handler methods at initialization.
     */
    @Override
    public void afterPropertiesSet() {
        initHandlerMe