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, 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 implement getInfo(), and 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():

Type	Data	Description
addChild	Container	Child container added to this Container.
addValve	Valve	Valve added to this Container.
removeChild	Container	Child container removed from this Container.
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. TODO: Review synchronisation around background processing. See bug 47024.

Author:

Craig R. McClanahan

Nested Class Summary

protected class	ContainerBase.ContainerBackgroundProcessor Private thread class to invoke the backgroundProcess method of this container and its children after a fixed delay.
protected static class	ContainerBase.NoopAccessLog
protected class	ContainerBase.PrivilegedAddChild Perform addChild with the permissions of this class.

Field Summary

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 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 ArrayList<ContainerListener>	listeners The container event listeners for this Container.
protected Loader	loader The Loader implementation with which this Container is associated.
protected Log	logger The Logger implementation with which this Container is associated.
protected String	logName Associated logger name.
protected Manager	manager The Manager implementation with which this Container is associated.
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 Realm	realm The Realm with which this Container is associated.
protected DirContext	resources The resources DirContext 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 PropertyChangeSupport	support The property change support for this component.

Fields inherited from class org.apache.catalina.util.LifecycleMBeanBase

mserver

Fields inherited from interface org.apache.catalina.Container

ADD_CHILD_EVENT, ADD_MAPPER_EVENT, ADD_VALVE_EVENT, REMOVE_CHILD_EVENT, REMOVE_MAPPER_EVENT, REMOVE_VALVE_EVENT

Fields inherited from interface org.apache.catalina.Lifecycle

AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, DESTROY_EVENT, INIT_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

ContainerBase()

Method Summary

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() Identify the AccessLog to use to log a request/response that was destined for this container but was handled earlier in the processing chain so that the request/response still appears in the correct access logs.
int	getBackgroundProcessorDelay() Get the delay between the invocation of the backgroundProcess method on this container and its children.
ObjectName[]	getChildren()
Cluster	getCluster() Return the Cluster with which this Container is associated.
protected String	getDomainInternal() Method implemented by sub-classes to identify the domain in which MBeans should be registered.
String	getInfo() Return descriptive information about this Container implementation and the corresponding version number, in the format <description>/<version>.
Loader	getLoader() Return the Loader with which this Container is associated.
Log	getLogger() Return the Logger for this Container.
Manager	getManager() Return the Manager with which this Container is associated.
Object	getMappingObject() Return an object which may be utilized for mapping to this component.
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.
DirContext	getResources() Return the resources DirContext object with which this Container is associated.
boolean	getStartChildren() Return if children of this container will be started automatically when they are added to this container.
void	invoke(Request request, Response response) Process the specified Request, to produce the corresponding Response, by invoking the first Valve in our pipeline (if any), or the basic Valve otherwise.
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.
protected String	logName() Return the abbreviated name of this container for logging messages
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	setLoader(Loader loader) Set the Loader with which this Container is associated.
void	setManager(Manager manager) Set the Manager 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	setResources(DirContext resources) Set the resources DirContext object 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.
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.

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

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

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

addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, init, removeLifecycleListener, setState, setState, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.catalina.Container

getObjectName

Methods inherited from interface org.apache.catalina.Lifecycle

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

Field Detail

children

protected HashMap<String,Container> children

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

backgroundProcessorDelay

protected int backgroundProcessorDelay

The processor delay for this component.

listeners

protected ArrayList<ContainerListener> listeners

The container event listeners for this Container.

loader

protected Loader loader

The Loader implementation with which this Container is associated.

logger

protected Log logger

The Logger implementation with which this Container is associated.

logName

protected String logName

Associated logger name.

manager

protected Manager manager

The Manager implementation with which this Container is associated.

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 Pipeline pipeline

The Pipeline object with which this Container is associated.

realm

protected Realm realm

The Realm with which this Container is associated.

resources

protected DirContext resources

The resources DirContext 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 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.

Constructor Detail

ContainerBase

public ContainerBase()

Method Detail

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

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

getInfo

public String getInfo()

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

Specified by:

getInfo in interface Container

getLoader

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.

Specified by:

getLoader in interface Container

setLoader

public void setLoader(Loader loader)

Set the Loader with which this Container is associated.

Specified by:

setLoader in interface Container

Parameters:

loader - The newly associated loader

getLogger

public Log getLogger()

Return the Logger for this Container.

Specified by:

getLogger in interface Container

getManager

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.

Specified by:

getManager in interface Container

setManager

public void setManager(Manager manager)

Set the Manager with which this Container is associated.

Specified by:

setManager in interface Container

Parameters:

manager - The newly associated Manager

getMappingObject

public Object getMappingObject()

Return an object which may be utilized for mapping to this component.

Specified by:

getMappingObject in interface Container

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

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

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.

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

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

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

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

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

getResources

public DirContext getResources()

Return the resources DirContext object 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.

Specified by:

getResources in interface Container

setResources

public void setResources(DirContext resources)

Set the resources DirContext object with which this Container is associated.

Specified by:

setResources in interface Container

Parameters:

resources - The newly associated DirContext

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

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

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

invoke

public void invoke(Request request,
                   Response response)
            throws IOException,
                   javax.servlet.ServletException

Process the specified Request, to produce the corresponding Response, by invoking the first Valve in our pipeline (if any), or the basic Valve otherwise.

Specified by:

invoke in interface Container

Parameters:

request - Request to be processed

response - Response to be produced

Throws:

IllegalStateException - if neither a pipeline or a basic Valve have been configured for this Container

IOException - if an input/output error occurred while processing

javax.servlet.ServletException - if a ServletException was thrown while processing this request

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

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

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

Identify the AccessLog to use to log a request/response that was destined for this container but was handled earlier in the processing chain so that the request/response still appears in the correct access logs.

Specified by:

getAccessLog in interface 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

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

logName

protected String logName()

Return the abbreviated name of this container for logging messages

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.

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.