How to tie domain name with application running on tomcat?

Thank you for helping . I have a problem When I follow your steps, bd does not work Please help me

As you are already running Apache, the easiest way to do this would be to set it up as a reverse proxy in front of Tomcat.

First, make sure mod_proxy is enabled by running:

sudo a2enmod proxy
sudo a2enmod proxy_http
service apache2 restart

Then create a new virtual host in a file named /etc/apache2/sites-available/tomcat.conf In it, you can configure it to point your domain to your Tomcat app:

<VirtualHost *:80>
	ServerName www.mysite.com

	ProxyRequests On
	ProxyPass / http://localhost:8080/Application_name/
	ProxyPassReverse / http://localhost:8080/Application_name/
</VirtualHost>

Note that the ServerName directive is important. Make sure that the virtual host for what Apache is already serving on port 80 also has ServerName set so that Apache can route the requests correctly.

Finally, enable the site and reload Apache:

sudo a2ensite tomcat
sudo service apache2 reload

Now visiting www.mysite.com should display the Tomcat application.

Como es eso de crear una maquina virtual , me podrian explicar por favor :( … Gracias