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org.apache.catalina
public interface: Container [javadoc | source]

All Known Implementing Classes:
    Engine, ExistingStandardWrapper, StandardEngine, StandardHost, Wrapper, Context, StandardContext, ContainerBase, Host, ReplicatedContext, StandardWrapper

A Container is an object that can execute requests received from a client, and return responses based on those requests. A Container may optionally support a pipeline of Valves that process the request in an order configured at runtime, by implementing the Pipeline interface as well.

Containers will exist at several conceptual levels within Catalina. The following examples represent common cases:

A given deployment of Catalina need not include Containers at all of the levels described above. For example, an administration application embedded within a network device (such as a router) might only contain a single Context and a few Wrappers, or even a single Wrapper if the application is relatively small. Therefore, Container implementations need to be designed so that they will operate correctly in the absence of parent Containers in a given deployment.

A Container may also be associated with a number of support components that provide functionality which might be shared (by attaching it to a parent Container) or individually customized. The following support components are currently recognized:

Field Summary
public static final  String ADD_CHILD_EVENT    The ContainerEvent event type sent when a child container is added by addChild()
public static final  String ADD_MAPPER_EVENT    The ContainerEvent event type sent when a Mapper is added by addMapper()
public static final  String ADD_VALVE_EVENT    The ContainerEvent event type sent when a valve is added by addValve(), if this Container supports pipelines. 
public static final  String REMOVE_CHILD_EVENT    The ContainerEvent event type sent when a child container is removed by removeChild()
public static final  String REMOVE_MAPPER_EVENT    The ContainerEvent event type sent when a Mapper is removed by removeMapper()
public static final  String REMOVE_VALVE_EVENT    The ContainerEvent event type sent when a valve is removed by removeValve(), if this Container supports pipelines. 
Method from org.apache.catalina.Container Summary:
addChild,   addContainerListener,   addPropertyChangeListener,   backgroundProcess,   findChild,   findChildren,   findContainerListeners,   getBackgroundProcessorDelay,   getCluster,   getInfo,   getLoader,   getLogger,   getManager,   getMappingObject,   getName,   getObjectName,   getParent,   getParentClassLoader,   getPipeline,   getRealm,   getResources,   invoke,   removeChild,   removeContainerListener,   removePropertyChangeListener,   setBackgroundProcessorDelay,   setCluster,   setLoader,   setManager,   setName,   setParent,   setParentClassLoader,   setRealm,   setResources
Method from org.apache.catalina.Container Detail:
 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
 public  void addContainerListener(ContainerListener listener)
    Add a container event listener to this component.
 public  void addPropertyChangeListener(PropertyChangeListener listener)
    Add a property change listener to this component.
 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.
 public Container findChild(String name)
    Return the child Container, associated with this Container, with the specified name (if any); otherwise, return null
 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.
 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.
 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.
 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.
 public String getInfo()
    Return descriptive information about this Container implementation and the corresponding version number, in the format <description>/<version>.
 public Loader getLoader()
    Return the Loader with which this Container is associated. If there is no associated Loader, return the Loader associated with our parent Container (if any); otherwise, return null.
 public Log getLogger()
    Return the Logger with which this Container is associated. If there is no associated Logger, return the Logger associated with our parent Container (if any); otherwise return null.
 public Manager getManager()
    Return the Manager with which this Container is associated. If there is no associated Manager, return the Manager associated with our parent Container (if any); otherwise return null.
 public Object getMappingObject()
    Return an object which may be utilized for mapping to this component.
 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.
 public String getObjectName()
    Return the JMX name associated with this container.
 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.
 public ClassLoader getParentClassLoader()
    Return the parent class loader (if any) for web applications.
 public Pipeline getPipeline()
    Return the Pipeline object that manages the Valves associated with this Container.
 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.
 public DirContext getResources()
    Return the Resources with which this Container is associated. If there is no associated Resources object, return the Resources associated with our parent Container (if any); otherwise return null.
 public  void invoke(Request request,
    Response response) throws IOException, ServletException
    Process the specified Request, and generate the corresponding Response, according to the design of this particular Container.
 public  void removeChild(Container child)
    Remove an existing child Container from association with this parent Container.
 public  void removeContainerListener(ContainerListener listener)
    Remove a container event listener from this component.
 public  void removePropertyChangeListener(PropertyChangeListener listener)
    Remove a property change listener from this component.
 public  void setBackgroundProcessorDelay(int delay)
    Set the delay between the invocation of the execute method on this container and its children.
 public  void setCluster(Cluster cluster)
    Set the Cluster with which this Container is associated.
 public  void setLoader(Loader loader)
    Set the Loader with which this Container is associated.
 public  void setManager(Manager manager)
    Set the Manager with which this Container is associated.
 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.
 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.
 public  void setParentClassLoader(ClassLoader parent)
    Set the parent class loader (if any) for web applications. 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.
 public  void setRealm(Realm realm)
    Set the Realm with which this Container is associated.
 public  void setResources(DirContext resources)
    Set the Resources object with which this Container is associated.