Package org.apache.catalina
Interface Container
- All Superinterfaces:
Lifecycle
- All Known Implementing Classes:
ContainerBase
,FailedContext
,ReplicatedContext
,StandardContext
,StandardEngine
,StandardHost
,StandardWrapper
,Tomcat.ExistingStandardWrapper
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 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 theServletContext
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.
- Author:
- Craig R. McClanahan, Remy Maucherat
-
Nested Class Summary
Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle
Lifecycle.SingleUse
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Field Summary
Modifier and TypeFieldDescriptionstatic final String
The ContainerEvent event type sent when a child container is added byaddChild()
.static final String
The ContainerEvent event type sent when a valve is added byaddValve()
, if this Container supports pipelines.static final String
The ContainerEvent event type sent when a child container is removed byremoveChild()
.static final String
The ContainerEvent event type sent when a valve is removed byremoveValve()
, if this Container supports pipelines.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
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Method Summary
Modifier and TypeMethodDescriptionvoid
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
Add a property change listener to this component.void
Execute a periodic task, such as reloading, etc.Obtain a child Container by name.Obtain the child Containers associated with this Container.Obtain the 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.Obtain the AccessLog to use to log a request/response that is destined for this container.int
Get the delay between the invocation of the backgroundProcess method on this container and its children.Obtain the location of CATALINA_BASE.Obtain the location of CATALINA_HOME.Get the Cluster for this container.Obtain the JMX domain under which this container will be / has been registered.Obtain the log to which events for this container should be logged.Return the logger name that the container will use.Calculate the key properties string to be added to an object'sObjectName
to indicate that it is associated with this container.getName()
Return a name string (suitable for use by humans) that describes this Container.Obtain the JMX name for this container.Get the parent container.Get the parent class loader.Return the Pipeline object that manages the Valves associated with this Container.getRealm()
Obtain the Realm with which this Container is associated.int
Obtain the number of threads available for starting and stopping any children associated with this container.void
Log a request/response that was destined for this container but has been handled earlier in the processing chain so that the request/response still appears in the correct access logs.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
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
Set a name string (suitable for use by humans) that describes this Container.void
Set the parent Container to which this Container is being added as a child.void
setParentClassLoader
(ClassLoader parent) Set the parent class loader for this component.void
Set the Realm with which this Container is associated.void
setStartStopThreads
(int startStopThreads) Sets the number of threads available for starting and stopping any children associated with this container.Methods inherited from interface org.apache.catalina.Lifecycle
addLifecycleListener, destroy, findLifecycleListeners, getState, getStateName, init, removeLifecycleListener, start, stop
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Field Details
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ADD_CHILD_EVENT
The ContainerEvent event type sent when a child container is added byaddChild()
.- See Also:
-
ADD_VALVE_EVENT
The ContainerEvent event type sent when a valve is added byaddValve()
, if this Container supports pipelines.- See Also:
-
REMOVE_CHILD_EVENT
The ContainerEvent event type sent when a child container is removed byremoveChild()
.- See Also:
-
REMOVE_VALVE_EVENT
The ContainerEvent event type sent when a valve is removed byremoveValve()
, if this Container supports pipelines.- See Also:
-
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Method Details
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getLogger
Log getLogger()Obtain the log to which events for this container should be logged.- 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
.
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getLogName
String getLogName()Return the logger name that the container will use.- Returns:
- the abbreviated name of this container for logging messages
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getObjectName
ObjectName getObjectName()Obtain the JMX name for this container.- Returns:
- the JMX name associated with this container.
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getDomain
String getDomain()Obtain the JMX domain under which this container will be / has been registered.- Returns:
- The JMX domain name
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getMBeanKeyProperties
String getMBeanKeyProperties()Calculate the key properties string to be added to an object'sObjectName
to indicate that it is associated with this container.- Returns:
- A string suitable for appending to the ObjectName
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getPipeline
Pipeline getPipeline()Return the Pipeline object that manages the Valves associated with this Container.- Returns:
- The Pipeline
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getCluster
Cluster getCluster()Get the Cluster for this 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
.
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setCluster
Set the Cluster with which this Container is associated.- Parameters:
cluster
- the Cluster with which this Container is associated.
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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 positive (which would mean they are using their own thread). Setting this to a positive value will cause a thread to be spawned. After waiting the specified amount of time, the thread will invoke thebackgroundProcess()
method on this container and all children with non-positive delay values.- 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.
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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
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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.- Returns:
- The human readable name of this container.
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setName
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)
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getParent
Container getParent()Get the parent container.- Returns:
- Return the Container for which this Container is a child, if
there is one. If there is no defined parent, return
null
.
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setParent
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
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getParentClassLoader
ClassLoader getParentClassLoader()Get the parent class loader.- Returns:
- the parent class loader for this component. If not set, return
getParent()
.getParentClassLoader()
. If no parent has been set, return the system class loader.
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setParentClassLoader
Set the parent class loader for this component. ForContext
s 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
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getRealm
Realm getRealm()Obtain the Realm with which this Container is associated.- Returns:
- The associated Realm; if there is no associated Realm, the
Realm associated with the parent Container (if any); otherwise
return
null
.
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setRealm
Set the Realm with which this Container is associated.- Parameters:
realm
- The newly associated Realm
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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
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'ssetParent()
method must be called, with this Container as an argument. This method may thrown anIllegalArgumentException
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 thesetParent()
method of the child ContainerIllegalArgumentException
- if the new child does not have a name unique from that of existing children of this ContainerIllegalStateException
- if this Container does not support child Containers
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addContainerListener
Add a container event listener to this component.- Parameters:
listener
- The listener to add
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addPropertyChangeListener
Add a property change listener to this component.- Parameters:
listener
- The listener to add
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findChild
Obtain a child Container by name.- 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.
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findChildren
Container[] findChildren()Obtain the child Containers associated with this Container.- Returns:
- An array containing all children of this container. If this Container has no children, a zero-length array is returned.
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findContainerListeners
ContainerListener[] findContainerListeners()Obtain the container listeners associated with this 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.
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removeChild
Remove an existing child Container from association with this parent Container.- Parameters:
child
- Existing child Container to be removed
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removeContainerListener
Remove a container event listener from this component.- Parameters:
listener
- The listener to remove
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removePropertyChangeListener
Remove a property change listener from this component.- Parameters:
listener
- The listener to remove
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fireContainerEvent
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.- Parameters:
type
- Event typedata
- Event data
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logAccess
Log a request/response that was destined for this container but has been handled earlier in the processing chain so that the request/response still appears in the correct access logs.- Parameters:
request
- Request (associated with the response) to logresponse
- Response (associated with the request) to logtime
- 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
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getAccessLog
AccessLog getAccessLog()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.- Returns:
- The AccessLog to use for a request/response destined for this container
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getStartStopThreads
int getStartStopThreads()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.- Returns:
- The currently configured number of threads used to start/stop children associated with this container
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setStartStopThreads
void setStartStopThreads(int startStopThreads) 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.- Parameters:
startStopThreads
- The new number of threads to be used
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getCatalinaBase
File getCatalinaBase()Obtain the location of CATALINA_BASE.- Returns:
- The location of CATALINA_BASE.
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getCatalinaHome
File getCatalinaHome()Obtain the location of CATALINA_HOME.- Returns:
- The location of CATALINA_HOME.
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