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):

- debug - Debugging detail level for this component. [0]

The standard `Realm` implementations that are currently available include the following (with additional configuration properties as specified):

- JDBCRealm - Implementation of `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:
  - connectionURL - The URL to use when connecting to this database. [REQUIRED - NO DEFAULT]
  - driverName - Fully qualified Java class name of the JDBC driver to be used. [REQUIRED - NO DEFAULT]
  - roleNameCol - Name of the database column that contains role names. [REQUIRED - NO DEFAULT]
  - userCredCol - Name of the database column that contains the user's credentials (i.e. password) in cleartext. [REQUIRED - NO DEFAULT]
  - userNameCol - Name of the database column that contains the user's logon username. [REQUIRED - NO DEFAULT]
  - userRoleTable - Name of the database table containing user role information. This table must include the columns specified by the `userNameCol` and `roleNameCol` properties. [REQUIRED - NO DEFAULT]
  - userTable - Name of the database table containing user information. This table must include the columns specified by the `userNameCol` and `userCredCol` properties. [REQUIRED - NO DEFAULT]
- MemoryRealm - Implementation of `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:
  - pathname - Pathname of the XML file containing our user and role information. If a relative pathname is specified, it is resolved against the pathname specified by the "catalina.home" system property. [conf/tomcat-users.xml]