Package org.apache.catalina

Interface Container

  • All Known Subinterfaces:
    Context, Engine, Host, Wrapper
    All Known Implementing Classes:
    AdHocWebModule, ContainerBase, ContextFacade, PEVirtualServer, PwcWebModule, StandardContext, StandardEngine, StandardHost, StandardWrapper, VirtualServer, WebModule
    public interface Container
    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:

    • Engine - Representation of the entire Catalina servlet engine, most likely containing one or more subcontainers that are either Host or Context implementations, or other custom groups.
    • Host - Representation of a virtual host containing a number of Contexts.
    • Context - Representation of a single ServletContext, which will typically contain one or more Wrappers for the supported servlets.
    • Wrapper - Representation of an individual servlet definition (which may support multiple servlet instances if the servlet itself implements SingleThreadModel).
    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:

    • Loader - Class loader to use for integrating new Java classes for this Container into the JVM in which Catalina is running.
    • Logger - Implementation of the log() method signatures of the ServletContext interface.
    • Manager - Manager for the pool of Sessions associated with this Container.
    • Realm - Read-only interface to a security domain, for authenticating user identities and their corresponding roles.
    • Resources - JNDI directory context enabling access to static resources, enabling custom linkages to existing server components when Catalina is embedded in a larger server.
    Version:
    $Revision: 1.4 $ $Date: 2006/12/15 18:56:51 $
    Author:
    Craig R. McClanahan, Remy Maucherat

    • Field Detail

      • ADD_CHILD_EVENT

        static final String ADD_CHILD_EVENT
        The ContainerEvent event type sent when a child container is added by addChild().
        See Also:
        Constant Field Values

      • ADD_MAPPER_EVENT

        static final String ADD_MAPPER_EVENT
        The ContainerEvent event type sent when a Mapper is added by addMapper().
        See Also:
        Constant Field Values

      • ADD_VALVE_EVENT

        static final String ADD_VALVE_EVENT
        The ContainerEvent event type sent when a valve is added by addValve(), if this Container supports pipelines.
        See Also:
        Constant Field Values

      • REMOVE_CHILD_EVENT

        static final String REMOVE_CHILD_EVENT
        The ContainerEvent event type sent when a child container is removed by removeChild().
        See Also:
        Constant Field Values

      • REMOVE_MAPPER_EVENT

        static final String REMOVE_MAPPER_EVENT
        The ContainerEvent event type sent when a Mapper is removed by removeMapper().
        See Also:
        Constant Field Values

      • REMOVE_VALVE_EVENT

        static final String REMOVE_VALVE_EVENT
        The ContainerEvent event type sent when a valve is removed by removeValve(), if this Container supports pipelines.
        See Also:
        Constant Field Values

    • Method Detail

      • getInfo

        String getInfo()
        Return descriptive information about this Container implementation and the corresponding version number, in the format <description>/<version>.

      • getLoader

        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.

      • setLoader

        void setLoader​(Loader loader)
        Set the Loader with which this Container is associated.
        Parameters:
        loader - The newly associated loader

      • getLogger

        Logger 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.

      • setLogger

        void setLogger​(Logger logger)
        Set the Logger with which this Container is associated.
        Parameters:
        logger - The newly associated Logger

      • getManager

        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.

      • setManager

        void setManager​(Manager manager)
        Set the Manager with which this Container is associated.
        Parameters:
        manager - The newly associated Manager

      • getMappingObject

        Object getMappingObject()
        Return an object which may be utilized for mapping to this component.

      • getPipeline

        Pipeline getPipeline()
        Return the Pipeline object that manages the Valves associated with this Container.

      • hasCustomPipeline

        boolean hasCustomPipeline()
        Returns:
        true if this container was configured with a custom pipeline, false otherwise

      • getBackgroundProcessorDelay

        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.

      • setBackgroundProcessorDelay

        void setBackgroundProcessorDelay​(int delay)
        Set the delay between the invocation of the execute method on this container and its children.
        Parameters:
        delay - The delay in seconds between the invocation of backgroundProcess methods

      • getName

        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.

      • setName

        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.
        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)

      • getParent

        Container getParent()
        Return the Container for which this Container is a child, if there is one. If there is no defined parent, return null.

      • setParent

        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.
        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

        ClassLoader getParentClassLoader()
        Return the parent class loader (if any) for web applications.

      • setParentClassLoader

        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.
        Parameters:
        parent - The new parent class loader

      • getRealm

        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.

      • setRealm

        void setRealm​(Realm realm)
        Set the Realm with which this Container is associated.
        Parameters:
        realm - The newly associated Realm

      • getResources

        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.

      • setResources

        void setResources​(DirContext resources)
           throws Exception
        Set the Resources object with which this Container is associated.
        Parameters:
        resources - The newly associated Resources
        Throws:
        Exception

      • backgroundProcess

        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.

      • addChild

        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
        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

        void addContainerListener​(ContainerListener listener)
        Add a container event listener to this component.
        Parameters:
        listener - The listener to add

      • fireContainerEvent

        void fireContainerEvent​(String type,
                        Object data)
        Notifies all event listeners of this Container of the given event.
        Parameters:
        type - Event type
        data - Event data

      • addPropertyChangeListener

        void addPropertyChangeListener​(PropertyChangeListener listener)
        Add a property change listener to this component.
        Parameters:
        listener - The listener to add

      • findChild

        Container findChild​(String name)
        Return the child Container, associated with this Container, with the specified name (if any); otherwise, return null
        Parameters:
        name - Name of the child Container to be retrieved

      • findChildren

        Container[] findChildren()
        Return the set of children Containers associated with this Container. If this Container has no children, a zero-length array is returned.

      • findContainerListeners

        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.

      • invoke

        void invoke​(Request request,
            Response response)
     throws IOException,
            jakarta.servlet.ServletException
        Process the specified Request, and generate the corresponding Response, according to the design of this particular Container.
        Parameters:
        request - Request to be processed
        response - Response to be produced
        Throws:
        IOException - if an input/output error occurred while processing
        jakarta.servlet.ServletException - if a ServletException was thrown while processing this request

      • removeChild

        void removeChild​(Container child)
        Remove an existing child Container from association with this parent Container.
        Parameters:
        child - Existing child Container to be removed

      • removeContainerListener

        void removeContainerListener​(ContainerListener listener)
        Remove a container event listener from this component.
        Parameters:
        listener - The listener to remove

      • removePropertyChangeListener

        void removePropertyChangeListener​(PropertyChangeListener listener)
        Remove a property change listener from this component.
        Parameters:
        listener - The listener to remove

      • isCheckIfRequestIsSecure

        boolean isCheckIfRequestIsSecure()
        Indicates whether the request will be checked to see if it is secure before adding Pragma and Cache-control headers when proxy caching has been disabled.
        Returns:
        true if the check is required; false otherwise.

      • setCheckIfRequestIsSecure

        void setCheckIfRequestIsSecure​(boolean checkIfRequestIsSecure)
        Sets the checkIfRequestIsSecure property of this Container. Setting this property to true will check if the request is secure before adding Pragma and Cache-Control headers when proxy caching has been disabled.
        Parameters:
        checkIfRequestIsSecure - true if check is required, false otherwise