By default, access to the manager application is disabled in Tomcat, by
virtue of omitting any valid users or roles from tomcat-users.xml.
To set up the manager application, add a user with the manager role to
this file. You can, for example’s sake, add the manager role and then
alter an existing user, such as tomcat, as follows:
<role rolename="manager"/>
<user username="tomcat" password="tomcat" roles="tomcat, manager"/>
If Tomcat is running,
restart it to read the updated tomcat-users.xml.
Next, check the URL
http://localhost:8080/manager/html.
You’ll be asked for a username and password, so enter the details of
the user that you configured.
**********
you can save this example as a file named index.jsp and place it in
the webapps/ROOT folder located in your Tomcat installation directory.
Then enter
http://localhost:8080/index.jsp into your browser as the
address