This package contains Realm implementations for the
various supported realm technologies for authenticating users and
identifying their associated roles.  The Realm that is
associated with a web application's Context (or a hierarchically
superior Container) is used to resolve authentication and role presence
questions when a web application uses container managed security as described
in the Servlet API Specification, version 2.2.
The implementations share a common base class that supports basic
functionality for all of the standard Realm implementations,
and can be configured by setting the following properties (default values
are in square brackets):
The standard Realm implementations that are currently
available include the following (with additional configuration properties
as specified):
Realm that operates
    from data stored in a relational database that is accessed via a JDBC
    driver.  The name of the driver, database connection information, and
    the names of the relevant tables and columns are configured with the
    following additional properties:
    userNameCol and roleNameCol properties.
        [REQUIRED - NO DEFAULT]userNameCol and userCredCol properties.
        [REQUIRED - NO DEFAULT]Realm that uses the
    contents of a simple XML file (conf/tomcat-users.xml) as the
    list of valid users and their roles.  This implementation is primarily to
    demonstrate that the authentication technology functions correctly, and is
    not anticipated as adequate for general purpose use.  This component
    supports the following additional properties: