How to get the content type of a file from a redirecting page?

如何从一个重定向页面获取文件内容类型？

youdao

This is useful for displaying a 404 page or redirecting to another route.

当需要显示404页面或者重定向到其它路由时，该特性非常有用。

youdao

This page is redirecting. If it does not response for a long time, you may click here.

我们正在将网页连结到繁体版网站，倘若没有反应，请按这里直接进入。

youdao

After that it will restrict subscribers' web browsing activities by redirecting them to a landing page.

BBC: Verizon to choke pirates' browsing speeds