ContainerBase (Apache Tomcat 10.1.5 API Documentation)

Package org.apache.catalina.core

## Class ContainerBase

- java.lang.Object
- - org.apache.catalina.util.LifecycleBase
  - - org.apache.catalina.util.LifecycleMBeanBase
    - - org.apache.catalina.core.ContainerBase

- All Implemented Interfaces:
    `MBeanRegistration`, `Container`, `JmxEnabled`, `Lifecycle`
  Direct Known Subclasses:
    `StandardContext`, `StandardEngine`, `StandardHost`, `StandardWrapper`

      public abstract class ContainerBase
      extends LifecycleMBeanBase
      implements Container

  Abstract implementation of the Container interface, providing common functionality required by nearly every implementation. Classes extending this base class must may implement a replacement for `invoke()`.

  All subclasses of this abstract base class will include support for a Pipeline object that defines the processing to be performed for each request received by the `invoke()` method of this class, utilizing the "Chain of Responsibility" design pattern. A subclass should encapsulate its own processing functionality as a `Valve`, and configure this Valve into the pipeline by calling `setBasic()`.

  This implementation fires property change events, per the JavaBeans design pattern, for changes in singleton properties. In addition, it fires the following `ContainerEvent` events to listeners who register themselves with `addContainerListener()`:

  ContainerEvents fired by this implementation
  Type | Data | Description
  --- | --- | ---
  `addChild` | `Container` | Child container added to this Container.
  ``pipeline`.addValve` | `Valve` | Valve added to this Container.
  `removeChild` | `Container` | Child container removed from this Container.
  ``pipeline`.removeValve` | `Valve` | Valve removed from this Container.
  `start` | `null` | Container was started.
  `stop` | `null` | Container was stopped.

  Subclasses that fire additional events should document them in the class comments of the implementation class.
  Author:
    Craig R. McClanahan

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class | Description
    --- | --- | ---
    `protected class` | `ContainerBase.ContainerBackgroundProcessor` | Private runnable class to invoke the backgroundProcess method of this container and its children after a fixed delay.
    `protected class` | `ContainerBase.ContainerBackgroundProcessorMonitor` |
    `protected class` | `ContainerBase.PrivilegedAddChild` | Perform addChild with the permissions of this class.

    - ### Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle

      `Lifecycle.SingleUse`

  - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected AccessLog` | `accessLog` | The access log to use for requests normally handled by this container that have been handled earlier in the processing chain.
    `protected int` | `backgroundProcessorDelay` | The processor delay for this component.
    `protected ScheduledFuture<?>` | `backgroundProcessorFuture` | The future allowing control of the background processor.
    `protected HashMap<String,​Container>` | `children` | The child Containers belonging to this Container, keyed by name.
    `protected Cluster` | `cluster` | The cluster with which this Container is associated.
    `protected List<ContainerListener>` | `listeners` | The container event listeners for this Container.
    `protected Log` | `logger` | The Logger implementation with which this Container is associated.
    `protected String` | `logName` | Associated logger name.
    `protected ScheduledFuture<?>` | `monitorFuture` |
    `protected String` | `name` | The human-readable name of this Container.
    `protected Container` | `parent` | The parent Container to which this Container is a child.
    `protected ClassLoader` | `parentClassLoader` | The parent class loader to be configured when we install a Loader.
    `protected Pipeline` | `pipeline` | The Pipeline object with which this Container is associated.
    `protected static StringManager` | `sm` | The string manager for this package.
    `protected boolean` | `startChildren` | Will children be started automatically when they are added.
    `protected ExecutorService` | `startStopExecutor` |
    `protected PropertyChangeSupport` | `support` | The property change support for this component.

    - ### Fields inherited from interface org.apache.catalina.Container

      `ADD_CHILD_EVENT, ADD_VALVE_EVENT, REMOVE_CHILD_EVENT, REMOVE_VALVE_EVENT`

    - ### Fields inherited from interface org.apache.catalina.Lifecycle

      `AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `ContainerBase()` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `addChild​(Container child)` | Add a new child Container to those associated with this Container, if supported.
    `void` | `addContainerListener​(ContainerListener listener)` | Add a container event listener to this component.
    `void` | `addPropertyChangeListener​(PropertyChangeListener listener)` | Add a property change listener to this component.
    `void` | `addValve​(Valve valve)` | Convenience method, intended for use by the digester to simplify the process of adding Valves to containers.
    `void` | `backgroundProcess()` | Execute a periodic task, such as reloading, etc.
    `protected void` | `destroyInternal()` | Sub-classes wishing to perform additional clean-up should override this method, ensuring that super.destroyInternal() is the last call in the overriding method.
    `Container` | `findChild​(String name)` | Return the child Container, associated with this Container, with the specified name (if any); otherwise, return `null`
    `Container[]` | `findChildren()` | Return the set of children Containers associated with this Container.
    `ContainerListener[]` | `findContainerListeners()` | Return the set of container listeners associated with this Container.
    `void` | `fireContainerEvent​(String type, Object data)` | Notify all container event listeners that a particular event has occurred for this Container.
    `AccessLog` | `getAccessLog()` | Obtain the AccessLog to use to log a request/response that is destined for this container.
    `int` | `getBackgroundProcessorDelay()` | Get the delay between the invocation of the backgroundProcess method on this container and its children.
    `File` | `getCatalinaBase()` | Obtain the location of CATALINA_BASE.
    `File` | `getCatalinaHome()` | Obtain the location of CATALINA_HOME.
    `ObjectName[]` | `getChildren()` |
    `Cluster` | `getCluster()` | Return the Cluster with which this Container is associated.
    `protected Cluster` | `getClusterInternal()` |
    `protected String` | `getDomainInternal()` | Method implemented by sub-classes to identify the domain in which MBeans should be registered.
    `Log` | `getLogger()` | Return the Logger for this Container.
    `String` | `getLogName()` | Return the logger name that the container will use.
    `String` | `getMBeanKeyProperties()` | Calculate the key properties string to be added to an object's `ObjectName` to indicate that it is associated with this container.
    `String` | `getName()` | Return a name string (suitable for use by humans) that describes this Container.
    `Container` | `getParent()` | Return the Container for which this Container is a child, if there is one.
    `ClassLoader` | `getParentClassLoader()` | Return the parent class loader (if any) for this web application.
    `Pipeline` | `getPipeline()` | Return the Pipeline object that manages the Valves associated with this Container.
    `Realm` | `getRealm()` | Return the Realm with which this Container is associated.
    `protected Realm` | `getRealmInternal()` |
    `boolean` | `getStartChildren()` | Return if children of this container will be started automatically when they are added to this container.
    `int` | `getStartStopThreads()` | Obtain the number of threads available for starting and stopping any children associated with this container.
    `protected void` | `initInternal()` | Sub-classes wishing to perform additional initialization should override this method, ensuring that super.initInternal() is the first call in the overriding method.
    `void` | `logAccess​(Request request, Response response, long time, boolean useDefault)` | Check this container for an access log and if none is found, look to the parent.
    `void` | `removeChild​(Container child)` | Remove an existing child Container from association with this parent Container.
    `void` | `removeContainerListener​(ContainerListener listener)` | Remove a container event listener from this component.
    `void` | `removePropertyChangeListener​(PropertyChangeListener listener)` | Remove a property change listener from this component.
    `void` | `setBackgroundProcessorDelay​(int delay)` | Set the delay between the invocation of the execute method on this container and its children.
    `void` | `setCluster​(Cluster cluster)` | Set the Cluster with which this Container is associated.
    `void` | `setName​(String name)` | Set a name string (suitable for use by humans) that describes this Container.
    `void` | `setParent​(Container container)` | Set the parent Container to which this Container is being added as a child.
    `void` | `setParentClassLoader​(ClassLoader parent)` | Set the parent class loader (if any) for this web application.
    `void` | `setRealm​(Realm realm)` | Set the Realm with which this Container is associated.
    `void` | `setStartChildren​(boolean startChildren)` | Set if children of this container will be started automatically when they are added to this container.
    `void` | `setStartStopThreads​(int startStopThreads)` | Sets the number of threads available for starting and stopping any children associated with this container.
    `protected void` | `startInternal()` | Start this component and implement the requirements of `LifecycleBase.startInternal()`.
    `protected void` | `stopInternal()` | Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.
    `protected void` | `threadStart()` | Start the background thread that will periodically check for session timeouts.
    `protected void` | `threadStop()` | Stop the background thread that is periodically checking for session timeouts.
    `String` | `toString()` |

    - ### Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase

      `getDomain, getObjectName, getObjectNameKeyProperties, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister, unregister`

    - ### Methods inherited from class org.apache.catalina.util.LifecycleBase

      `addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, getThrowOnFailure, init, removeLifecycleListener, setState, setState, setThrowOnFailure, start, stop`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface org.apache.catalina.Container

      `getDomain, getObjectName`

    - ### Methods inherited from interface org.apache.catalina.Lifecycle

      `addLifecycleListener, destroy, findLifecycleListeners, getState, getStateName, init, removeLifecycleListener, start, stop`

- - ### Field Detail

    - #### children

          protected final HashMap<String,​Container> children

      The child Containers belonging to this Container, keyed by name.

    - #### backgroundProcessorDelay

          protected int backgroundProcessorDelay

      The processor delay for this component.

    - #### backgroundProcessorFuture

          protected ScheduledFuture<?> backgroundProcessorFuture

      The future allowing control of the background processor.

    - #### monitorFuture

          protected ScheduledFuture<?> monitorFuture

    - #### listeners

          protected final List<ContainerListener> listeners

      The container event listeners for this Container. Implemented as a CopyOnWriteArrayList since listeners may invoke methods to add/remove themselves or other listeners and with a ReadWriteLock that would trigger a deadlock.

    - #### logger

          protected Log logger

      The Logger implementation with which this Container is associated.

    - #### logName

          protected String logName

      Associated logger name.

    - #### cluster

          protected Cluster cluster

      The cluster with which this Container is associated.

    - #### name

          protected String name

      The human-readable name of this Container.

    - #### parent

          protected Container parent

      The parent Container to which this Container is a child.

    - #### parentClassLoader

          protected ClassLoader parentClassLoader

      The parent class loader to be configured when we install a Loader.

    - #### pipeline

          protected final Pipeline pipeline

      The Pipeline object with which this Container is associated.

    - #### sm

          protected static final StringManager sm

      The string manager for this package.

    - #### startChildren

          protected boolean startChildren

      Will children be started automatically when they are added.

    - #### support

          protected final PropertyChangeSupport support

      The property change support for this component.

    - #### accessLog

          protected volatile AccessLog accessLog

      The access log to use for requests normally handled by this container that have been handled earlier in the processing chain.

    - #### startStopExecutor

          protected ExecutorService startStopExecutor

  - ### Constructor Detail

    - #### ContainerBase

          public ContainerBase()

  - ### Method Detail

    - #### getStartStopThreads

          public int getStartStopThreads()

      Description copied from interface: `Container`
      Obtain the number of threads available for starting and stopping any children associated with this container. This allows start/stop calls to children to be processed in parallel.
      Specified by:
        `getStartStopThreads` in interface `Container`
      Returns:
        The currently configured number of threads used to start/stop children associated with this container

    - #### setStartStopThreads

          public void setStartStopThreads​(int startStopThreads)

      Description copied from interface: `Container`
      Sets the number of threads available for starting and stopping any children associated with this container. This allows start/stop calls to children to be processed in parallel.
      Specified by:
        `setStartStopThreads` in interface `Container`
      Parameters:
        `startStopThreads` - The new number of threads to be used

    - #### getBackgroundProcessorDelay

          public int getBackgroundProcessorDelay()

      Get the delay between the invocation of the backgroundProcess method on this container and its children. Child containers will not be invoked if their delay value is not negative (which would mean they are using their own thread). Setting this to a positive value will cause a thread to be spawn. After waiting the specified amount of time, the thread will invoke the executePeriodic method on this container and all its children.
      Specified by:
        `getBackgroundProcessorDelay` in interface `Container`
      Returns:
        The delay between the invocation of the backgroundProcess method on this container and its children. A non-positive value indicates that background processing will be managed by the parent.

    - #### setBackgroundProcessorDelay

          public void setBackgroundProcessorDelay​(int delay)

      Set the delay between the invocation of the execute method on this container and its children.
      Specified by:
        `setBackgroundProcessorDelay` in interface `Container`
      Parameters:
        `delay` - The delay in seconds between the invocation of backgroundProcess methods

    - #### getLogger

          public Log getLogger()

      Return the Logger for this Container.
      Specified by:
        `getLogger` in interface `Container`
      Returns:
        The Logger with which this Container is associated. If there is no associated Logger, return the Logger associated with the parent Container (if any); otherwise return `null`.

    - #### getLogName

          public String getLogName()

      Description copied from interface: `Container`
      Return the logger name that the container will use.
      Specified by:
        `getLogName` in interface `Container`
      Returns:
        the abbreviated name of this container for logging messages

    - #### getCluster

          public Cluster getCluster()

      Return the Cluster with which this Container is associated. If there is no associated Cluster, return the Cluster associated with our parent Container (if any); otherwise return `null`.
      Specified by:
        `getCluster` in interface `Container`
      Returns:
        The Cluster with which this Container is associated. If there is no associated Cluster, return the Cluster associated with our parent Container (if any); otherwise return `null`.

    - #### getClusterInternal

          protected Cluster getClusterInternal()

    - #### setCluster

          public void setCluster​(Cluster cluster)

      Set the Cluster with which this Container is associated.
      Specified by:
        `setCluster` in interface `Container`
      Parameters:
        `cluster` - The newly associated Cluster

    - #### getName

          public String getName()

      Return a name string (suitable for use by humans) that describes this Container. Within the set of child containers belonging to a particular parent, Container names must be unique.
      Specified by:
        `getName` in interface `Container`
      Returns:
        The human readable name of this container.

    - #### setName

          public void setName​(String name)

      Set a name string (suitable for use by humans) that describes this Container. Within the set of child containers belonging to a particular parent, Container names must be unique.
      Specified by:
        `setName` in interface `Container`
      Parameters:
        `name` - New name of this container
      Throws:
        `IllegalStateException` - if this Container has already been added to the children of a parent Container (after which the name may not be changed)

    - #### getStartChildren

          public boolean getStartChildren()

      Return if children of this container will be started automatically when they are added to this container.
      Returns:
        `true` if the children will be started

    - #### setStartChildren

          public void setStartChildren​(boolean startChildren)

      Set if children of this container will be started automatically when they are added to this container.
      Parameters:
        `startChildren` - New value of the startChildren flag

    - #### getParent

          public Container getParent()

      Return the Container for which this Container is a child, if there is one. If there is no defined parent, return `null`.
      Specified by:
        `getParent` in interface `Container`
      Returns:
        Return the Container for which this Container is a child, if there is one. If there is no defined parent, return `null`.

    - #### setParent

          public void setParent​(Container container)

      Set the parent Container to which this Container is being added as a child. This Container may refuse to become attached to the specified Container by throwing an exception.
      Specified by:
        `setParent` in interface `Container`
      Parameters:
        `container` - Container to which this Container is being added as a child
      Throws:
        `IllegalArgumentException` - if this Container refuses to become attached to the specified Container

    - #### getParentClassLoader

          public ClassLoader getParentClassLoader()

      Return the parent class loader (if any) for this web application. This call is meaningful only after a Loader has been configured.
      Specified by:
        `getParentClassLoader` in interface `Container`
      Returns:
        the parent class loader for this component. If not set, return `Container.getParent()`.`Container.getParentClassLoader()`. If no parent has been set, return the system class loader.

    - #### setParentClassLoader

          public void setParentClassLoader​(ClassLoader parent)

      Set the parent class loader (if any) for this web application. This call is meaningful only before a Loader has been configured, and the specified value (if non-null) should be passed as an argument to the class loader constructor.
      Specified by:
        `setParentClassLoader` in interface `Container`
      Parameters:
        `parent` - The new parent class loader

    - #### getPipeline

          public Pipeline getPipeline()

      Return the Pipeline object that manages the Valves associated with this Container.
      Specified by:
        `getPipeline` in interface `Container`
      Returns:
        The Pipeline

    - #### getRealm

          public Realm getRealm()

      Return the Realm with which this Container is associated. If there is no associated Realm, return the Realm associated with our parent Container (if any); otherwise return `null`.
      Specified by:
        `getRealm` in interface `Container`
      Returns:
        The associated Realm; if there is no associated Realm, the Realm associated with the parent Container (if any); otherwise return `null`.

    - #### getRealmInternal

          protected Realm getRealmInternal()

    - #### setRealm

          public void setRealm​(Realm realm)

      Set the Realm with which this Container is associated.
      Specified by:
        `setRealm` in interface `Container`
      Parameters:
        `realm` - The newly associated Realm

    - #### addChild

          public void addChild​(Container child)

      Add a new child Container to those associated with this Container, if supported. Prior to adding this Container to the set of children, the child's `setParent()` method must be called, with this Container as an argument. This method may thrown an `IllegalArgumentException` if this Container chooses not to be attached to the specified Container, in which case it is not added
      Specified by:
        `addChild` in interface `Container`
      Parameters:
        `child` - New child Container to be added
      Throws:
        `IllegalArgumentException` - if this exception is thrown by the `setParent()` method of the child Container
        `IllegalArgumentException` - if the new child does not have a name unique from that of existing children of this Container
        `IllegalStateException` - if this Container does not support child Containers

    - #### addContainerListener

          public void addContainerListener​(ContainerListener listener)

      Add a container event listener to this component.
      Specified by:
        `addContainerListener` in interface `Container`
      Parameters:
        `listener` - The listener to add

    - #### addPropertyChangeListener

          public void addPropertyChangeListener​(PropertyChangeListener listener)

      Add a property change listener to this component.
      Specified by:
        `addPropertyChangeListener` in interface `Container`
      Parameters:
        `listener` - The listener to add

    - #### findChild

          public Container findChild​(String name)

      Return the child Container, associated with this Container, with the specified name (if any); otherwise, return `null`
      Specified by:
        `findChild` in interface `Container`
      Parameters:
        `name` - Name of the child Container to be retrieved
      Returns:
        The child Container with the given name or `null` if no such child exists.

    - #### findChildren

          public Container[] findChildren()

      Return the set of children Containers associated with this Container. If this Container has no children, a zero-length array is returned.
      Specified by:
        `findChildren` in interface `Container`
      Returns:
        An array containing all children of this container. If this Container has no children, a zero-length array is returned.

    - #### findContainerListeners

          public ContainerListener[] findContainerListeners()

      Return the set of container listeners associated with this Container. If this Container has no registered container listeners, a zero-length array is returned.
      Specified by:
        `findContainerListeners` in interface `Container`
      Returns:
        An array containing the container listeners associated with this Container. If this Container has no registered container listeners, a zero-length array is returned.

    - #### removeChild

          public void removeChild​(Container child)

      Remove an existing child Container from association with this parent Container.
      Specified by:
        `removeChild` in interface `Container`
      Parameters:
        `child` - Existing child Container to be removed

    - #### removeContainerListener

          public void removeContainerListener​(ContainerListener listener)

      Remove a container event listener from this component.
      Specified by:
        `removeContainerListener` in interface `Container`
      Parameters:
        `listener` - The listener to remove

    - #### removePropertyChangeListener

          public void removePropertyChangeListener​(PropertyChangeListener listener)

      Remove a property change listener from this component.
      Specified by:
        `removePropertyChangeListener` in interface `Container`
      Parameters:
        `listener` - The listener to remove

    - #### initInternal

          protected void initInternal()
                               throws LifecycleException

      Description copied from class: `LifecycleMBeanBase`
      Sub-classes wishing to perform additional initialization should override this method, ensuring that super.initInternal() is the first call in the overriding method.
      Overrides:
        `initInternal` in class `LifecycleMBeanBase`
      Throws:
        `LifecycleException` - If the initialisation fails

    - #### startInternal

          protected void startInternal()
                                throws LifecycleException

      Start this component and implement the requirements of `LifecycleBase.startInternal()`.
      Specified by:
        `startInternal` in class `LifecycleBase`
      Throws:
        `LifecycleException` - if this component detects a fatal error that prevents this component from being used

    - #### stopInternal

          protected void stopInternal()
                               throws LifecycleException

      Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.
      Specified by:
        `stopInternal` in class `LifecycleBase`
      Throws:
        `LifecycleException` - if this component detects a fatal error that prevents this component from being used

    - #### destroyInternal

          protected void destroyInternal()
                                  throws LifecycleException

      Description copied from class: `LifecycleMBeanBase`
      Sub-classes wishing to perform additional clean-up should override this method, ensuring that super.destroyInternal() is the last call in the overriding method.
      Overrides:
        `destroyInternal` in class `LifecycleMBeanBase`
      Throws:
        `LifecycleException` - If the destruction fails

    - #### logAccess

          public void logAccess​(Request request,
                                Response response,
                                long time,
                                boolean useDefault)

      Check this container for an access log and if none is found, look to the parent. If there is no parent and still none is found, use the NoOp access log.
      Specified by:
        `logAccess` in interface `Container`
      Parameters:
        `request` - Request (associated with the response) to log
        `response` - Response (associated with the request) to log
        `time` - Time taken to process the request/response in milliseconds (use 0 if not known)
        `useDefault` - Flag that indicates that the request/response should be logged in the engine's default access log

    - #### getAccessLog

          public AccessLog getAccessLog()

      Description copied from interface: `Container`
      Obtain the AccessLog to use to log a request/response that is destined for this container. This is typically used when the request/response was handled (and rejected) earlier in the processing chain so that the request/response still appears in the correct access logs.
      Specified by:
        `getAccessLog` in interface `Container`
      Returns:
        The AccessLog to use for a request/response destined for this container

    - #### addValve

          public void addValve​(Valve valve)

      Convenience method, intended for use by the digester to simplify the process of adding Valves to containers. See `Pipeline.addValve(Valve)` for full details. Components other than the digester should use `getPipeline()`.`addValve(Valve)` in case a future implementation provides an alternative method for the digester to use.
      Parameters:
        `valve` - Valve to be added
      Throws:
        `IllegalArgumentException` - if this Container refused to accept the specified Valve
        `IllegalArgumentException` - if the specified Valve refuses to be associated with this Container
        `IllegalStateException` - if the specified Valve is already associated with a different Container

    - #### backgroundProcess

          public void backgroundProcess()

      Execute a periodic task, such as reloading, etc. This method will be invoked inside the classloading context of this container. Unexpected throwables will be caught and logged.
      Specified by:
        `backgroundProcess` in interface `Container`

    - #### getCatalinaBase

          public File getCatalinaBase()

      Description copied from interface: `Container`
      Obtain the location of CATALINA_BASE.
      Specified by:
        `getCatalinaBase` in interface `Container`
      Returns:
        The location of CATALINA_BASE.

    - #### getCatalinaHome

          public File getCatalinaHome()

      Description copied from interface: `Container`
      Obtain the location of CATALINA_HOME.
      Specified by:
        `getCatalinaHome` in interface `Container`
      Returns:
        The location of CATALINA_HOME.

    - #### fireContainerEvent

          public void fireContainerEvent​(String type,
                                         Object data)

      Notify all container event listeners that a particular event has occurred for this Container. The default implementation performs this notification synchronously using the calling thread.
      Specified by:
        `fireContainerEvent` in interface `Container`
      Parameters:
        `type` - Event type
        `data` - Event data

    - #### getDomainInternal

          protected String getDomainInternal()

      Description copied from class: `LifecycleMBeanBase`
      Method implemented by sub-classes to identify the domain in which MBeans should be registered.
      Specified by:
        `getDomainInternal` in class `LifecycleMBeanBase`
      Returns:
        The name of the domain to use to register MBeans.

    - #### getMBeanKeyProperties

          public String getMBeanKeyProperties()

      Description copied from interface: `Container`
      Calculate the key properties string to be added to an object's `ObjectName` to indicate that it is associated with this container.
      Specified by:
        `getMBeanKeyProperties` in interface `Container`
      Returns:
        A string suitable for appending to the ObjectName

    - #### getChildren

          public ObjectName[] getChildren()

    - #### threadStart

          protected void threadStart()

      Start the background thread that will periodically check for session timeouts.

    - #### threadStop

          protected void threadStop()

      Stop the background thread that is periodically checking for session timeouts.

    - #### toString

          public final String toString()

      Overrides:
        `toString` in class `Object`