org.sape.carbon.core.config.node
Class NestedConfigurationDocument

java.lang.Object
  |
  +--org.sape.carbon.core.config.node.AbstractNode
        |
        +--org.sape.carbon.core.config.node.AbstractConfigurationDocument
              |
              +--org.sape.carbon.core.config.node.NestedConfigurationDocument

All Implemented Interfaces:

ConfigurationDocument, Node

public class NestedConfigurationDocument

extends AbstractConfigurationDocument

ConfigurationDocument implementation for configurations nested within other ConfigurationDocuments. Parents of this Node can only be AbsractConfigurationDocuments. Copyright 2002 Sapient

Since:

carbon 1.1

Version:

$Revision: 1.12 $($Author: dvoet $ / $Date: 2003/12/11 18:43:31 $)

Author:

Douglas Voet, Sep 11, 2002

Field Summary

Fields inherited from class org.sape.carbon.core.config.node.AbstractConfigurationDocument

configuration

Fields inherited from class org.sape.carbon.core.config.node.AbstractNode

childNodes, nodeListeners

Fields inherited from interface org.sape.carbon.core.config.node.Node

DELIMITER

Constructor Summary

protected

NestedConfigurationDocument(AbstractConfigurationDocument parent, String name) This should only be called by NestedConfigurationDocumentFactory

Method Summary

protected boolean	backingDataExists() Method called from the refresh method to see if the backing data still exists.
protected void	destroyBackingData() This method is called by remove to destroy the data backing this node in the data source.
private Configuration	getConfiguration() Helper method to get the configuration for this node.
boolean	isRemoved() Used to tell whether or not the backing data of a node has been removed.
void	onChange() Called by parent documents when the have changed in order for this node to notify its listeners that a change has occured
protected InputStream	openInputStream() This should never be called.
protected OutputStream	openOutputStream() This should never be called.
Configuration	readConfiguration() This implementation uses the ConfigurationFormatService to read from the backing data store.
void	writeConfiguration(Configuration config) This implementation uses the ConfigurationFormatService to write to the backing data store.

Methods inherited from class org.sape.carbon.core.config.node.AbstractConfigurationDocument

addNestedConfigurationDocument, closeInputStream, closeOutputStream, getAllChildNames, getFormatService, getNestedNodeFactory, issueNodeModifiedEvent, loadChild, notifyNestedDocuments, refresh, remove, writeChildReferences

Methods inherited from class org.sape.carbon.core.config.node.AbstractNode

addNodeListener, addNodeListener, addNodeListener, containsChild, fetchChild, fetchChildren, getAbsoluteName, getAddOrLoadChildLock, getAllowsChildren, getName, getParent, getReadOrAlterNodeLock, issueChildLoadedEvent, issueNodeRemovedEvent, removeRemovedChildren, setRemoved, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.sape.carbon.core.config.node.Node

addNodeListener, addNodeListener, containsChild, fetchChild, fetchChildren, getAbsoluteName, getAllowsChildren, getName, getParent

Constructor Detail

NestedConfigurationDocument

protected NestedConfigurationDocument(AbstractConfigurationDocument parent,
                                      String name)

This should only be called by NestedConfigurationDocumentFactory

Parameters:

parent -

name -

Method Detail

readConfiguration

public Configuration readConfiguration()
                                throws NodeIOException,
                                       ConfigurationFormatException

Description copied from class: AbstractConfigurationDocument

This implementation uses the ConfigurationFormatService to read from the backing data store. It calls the abstract method openInputStream to open an InputStream to read the Configuration from then closes it before it exits.

This method is synchronized to prevent multiple readers from loading the Configuration at once and to make sure that no one is writing a new Configuration while someone else is reading.

Specified by:

readConfiguration in interface ConfigurationDocument

Overrides:

readConfiguration in class AbstractConfigurationDocument

Returns:

the Configuration object within this ConfigurationDocument

Throws:

NodeIOException - indicates a generic exception writing the configuration

ConfigurationFormatException - indicates an error formating the config document

See Also:

ConfigurationDocument.readConfiguration()

writeConfiguration

public void writeConfiguration(Configuration config)
                        throws NodeIOException,
                               ConfigurationFormatException

Description copied from class: AbstractConfigurationDocument

This implementation uses the ConfigurationFormatService to write to the backing data store. It calls the abstract method openOutpuStream to open an OutputStream to write the Configuration to then closes it before it exits.

This method is synchronized internally to prevent multiple writes from saving Configurations concurrently and to make sure that no one is writing a new Configuration while someone else is reading.

Specified by:

writeConfiguration in interface ConfigurationDocument

Overrides:

writeConfiguration in class AbstractConfigurationDocument

Parameters:

config - the Configuration to write to the backing data store

Throws:

NodeIOException - indicates a generic exception writing the configuration

ConfigurationFormatException - indicates an error formating the config document

See Also:

ConfigurationDocument.writeConfiguration(Configuration)

onChange

public void onChange()

Called by parent documents when the have changed in order for this node to notify its listeners that a change has occured

openInputStream

protected InputStream openInputStream()
                               throws IOException

This should never be called. If it is, this class was not written correctly. All reads should be done via parent's document

Specified by:

openInputStream in class AbstractConfigurationDocument

Returns:

never returns

Throws:

IOException - never thrown

UnsupportedOperationException - always thrown to indicate this method is not supported.

openOutputStream

protected OutputStream openOutputStream()
                                 throws IOException

This should never be called. If it is, this class was not written correctly. All writes should be done via parent's document

Specified by:

openOutputStream in class AbstractConfigurationDocument

Returns:

never returns

Throws:

IOException - never thrown

UnsupportedOperationException - always thrown to indicate this method is not supported.

destroyBackingData

protected void destroyBackingData()
                           throws NodeRemovalException

Description copied from class: AbstractNode

This method is called by remove to destroy the data backing this node in the data source. Implementations of this method should remove all traces of the Node's existence

Specified by:

destroyBackingData in class AbstractNode

Throws:

NodeRemovalException - indicates an error removing the node

See Also:

AbstractNode.destroyBackingData()

backingDataExists

protected boolean backingDataExists()

Description copied from class: AbstractNode

Method called from the refresh method to see if the backing data still exists. If it exists, the isRemoved flag is set to false, if it does not, the isRemoved flag is set to true.

Specified by:

backingDataExists in class AbstractNode

Returns:

boolean true if the backing date exists, false otherwise

See Also:

AbstractNode.backingDataExists()

isRemoved

public boolean isRemoved()

Description copied from interface: Node

Used to tell whether or not the backing data of a node has been removed.

Specified by:

isRemoved in interface Node

Overrides:

isRemoved in class AbstractNode

Returns:

true if the backing data of a node has been removed

See Also:

Node.isRemoved()

getConfiguration

private Configuration getConfiguration()
                                throws NodeIOException,
                                       ConfigurationFormatException

Helper method to get the configuration for this node.

Returns:

the configuration document

Throws:

NodeIOException - indicates an error reading the node

ConfigurationFormatException - indicates an error with the configuration document