Sitemap xml file; Does the url have to end with an ".htm"?

I have a website which has .htaccess rewrite rules. And alot of them.

This means for example that

    www.mydomain.com/classifieds/something_very_very_very_very_开发者_运维问答Very_very_looong.php?id=12345

    becomes

    www.mydomain.com/classifieds/12345

Now, this might be a stupid question, but I must be sure...

I have followed several guides on how to create a good search engine friendly sitemap, and they all have a .html or .htm at the end of the url adress... My rewrite-rule uses no such endings, so for me it would have no ending at all. Will this work as good anyways?

No there's no need for your pages to end with .html.
If you index your pages correctly in sitemap.xml then they should be readable by the web crawler