一般我看设置拦截器，都是继承HandlerInterceptor类，而老师您却采用到的是继承HandlerInterceptorAdapter，我看了下源码发现HandlerInterceptorAdapter是实现了AsyncHandlerInterceptor接口，而这接口也是继承了HandlerInterceptor类，就是相比于HandlerInterceptor多了一个afterConcurrentHandlingStarted方法，我大体看了下英文注释，貌似主要用于异步请求处理的场景。该方法注释如下：

<p>When a handler starts an asynchronous request, the {@link DispatcherServlet}
* exits without invoking {@code postHandle} and {@code afterCompletion} as it
* normally does for a synchronous request, since the result of request handling
* (e.g. ModelAndView) is likely not yet ready and will be produced concurrently
* from another thread. In such scenarios, {@link #afterConcurrentHandlingStarted}
* is invoked instead, allowing implementations to perform tasks such as cleaning
* up thread-bound attributes before releasing the thread to the Servlet container.

这段话，自己翻译后，还是感觉理解得不透彻，比如“请求处理结果（例如ModelAndView）可能还没有准备好，且将同从另一个线程里产生，在这样的情况下使用afterConcurrentHandlingStarted方法”就总感觉自己翻译的特别扭也理解不顺。特问老师两个问题：

1.  afterConcurrentHandlingStarted这方法的使用场景

2. HandlerInterceptorAdapter相比于HandlerInterceptor的优势是不是就在于上述这个方法。