# Package org.apache.catalina

Interface Summary
Interface | Description
--- | ---
AccessLog | Intended for use by a `Valve` to indicate that the `Valve` provides access logging.
AsyncDispatcher |
Authenticator | An Authenticator is a component (usually a Valve or Container) that provides some sort of authentication service.
Cluster | A Cluster works as a Cluster client/server for the local host Different Cluster implementations can be used to support different ways to communicate within the Cluster.
Contained | Decoupling interface which specifies that an implementing class is associated with at most one Container instance.
Container | A Container is an object that can execute requests received from a client, and return responses based on those requests.
ContainerListener | Interface defining a listener for significant Container generated events.
ContainerServlet | A ContainerServlet is a servlet that has access to Catalina internal functionality, and is loaded from the Catalina class loader instead of the web application class loader.
Context | A Context is a Container that represents a servlet context, and therefore an individual web application, in the Catalina servlet engine.
DistributedManager | Interface implemented by session managers that do not keep a complete copy of all sessions in memory but do know where every session is.
Engine | An Engine is a Container that represents the entire Catalina servlet engine.
Executor |
Group | Abstract representation of a group of `User`s in a `UserDatabase`.
Host | A Host is a Container that represents a virtual host in the Catalina servlet engine.
InstanceListener | Interface defining a listener for significant events related to a specific servlet instance, rather than to the Wrapper component that is managing that instance.
Lifecycle | Common interface for component life cycle methods.
LifecycleListener | Interface defining a listener for significant events (including "component start" and "component stop" generated by a component that implements the Lifecycle interface.
Loader | A Loader represents a Java ClassLoader implementation that can be used by a Container to load class files (within a repository associated with the Loader) that are designed to be reloaded upon request, as well as a mechanism to detect whether changes have occurred in the underlying repository.
Manager | A Manager manages the pool of Sessions that are associated with a particular Container.
Pipeline | Interface describing a collection of Valves that should be executed in sequence when the `invoke()` method is invoked.
Realm | A Realm is a read-only facade for an underlying security realm used to authenticate individual users, and identify the security roles associated with those users.
Role | Abstract representation of a security role, suitable for use in environments like JAAS that want to deal with `Principals`.
Server | A `Server` element represents the entire Catalina servlet container.
Service | A Service is a group of one or more Connectors that share a single Container to process their incoming requests.
Session | A Session is the Catalina-internal facade for an `HttpSession` that is used to maintain state information between requests for a particular user of a web application.
SessionListener | Interface defining a listener for significant Session generated events.
Store | A Store is the abstraction of a Catalina component that provides persistent storage and loading of Sessions and their associated user data.
User | Abstract representation of a user in a `UserDatabase`.
UserDatabase | Abstract representation of a database of `User`s and `Group`s that can be maintained by an application, along with definitions of corresponding `Role`s, and referenced by a `Realm` for authentication and access control.
Valve | A Valve is a request processing component associated with a particular Container.
Wrapper | A Wrapper is a Container that represents an individual servlet definition from the deployment descriptor of the web application.

Class Summary
Class | Description
--- | ---
CatalinaFactory | Deprecated There was no demand for this capability and it will be removed in Tomcat 8.0.x
ContainerEvent | General event for notifying listeners of significant changes on a Container.
Globals | Global constants that are applicable to multiple packages within Catalina.
InstanceEvent | General event for notifying listeners of significant events related to a specific instance of a Servlet, or a specific instance of a Filter, as opposed to the Wrapper component that manages it.
LifecycleEvent | General event for notifying listeners of significant changes on a component that implements the Lifecycle interface.
SessionEvent | General event for notifying listeners of significant changes on a Session.

Enum Summary
Enum | Description
--- | ---
LifecycleState | The list of valid states for components that implement `Lifecycle`.

Exception Summary
Exception | Description
--- | ---
LifecycleException | General purpose exception that is thrown to indicate a lifecycle related problem.