The default handler is a very simple Controller interface with just one method, ModelAndView handleRequest(request, response).

默认的处理程序是非常简单的 Controller 接口，只有一个方法 ModelAndView handleRequest(request, response)。

youdao

If the default handler is set with the latter pair of methods, any thread that doesn't have its own exception handler will use the default.

如果使用第二对方法设置默认处理程序，那么没有自己的异常处理程序的所有线程都将使用默认处理程序。

youdao

If no event handlers processed the click, the event will travel back up the same path until it comes back to the root element, where the default click handler will ignore it.

如果没有事件处理程序处理这个单击事件，它就会沿着同样的路线再返回到根元素，这时根元素默认的单击处理程序将忽略该事件。

youdao