org.sape.carbon.core.config
Class DefaultRootConfigurationService

java.lang.Object
  |
  +--org.sape.carbon.core.config.DefaultRootConfigurationService

All Implemented Interfaces:

ConfigurationService

public class DefaultRootConfigurationService

extends Object

implements ConfigurationService

Implementation of RootConfigurationService that traverses the node tree to fetch and store configuration data. Copyright 2001 Sapient

Since:

carbon 1.0

Version:

$Revision: 1.43 $($Author: dvoet $ / $Date: 2003/12/11 18:43:31 $)

Author:

Greg Hinkle, December 2001

Field Summary

private ConfigurationCache	cache Cache storing previously accessed configuration objects.
private org.apache.commons.logging.Log	log Provides a handle to Apache-commons logger
private Node	rootNode Handle to the root node used by this ConfigurationService.

Constructor Summary

protected

DefaultRootConfigurationService(ConfigurationDocument configurationDocument) protected constructor prevents direct instantiation by classes other than the DefaultConfigurationServiceFactory but does not prevent extension.

Method Summary

void	addNodeListener(String nodeName, ConfigurationEventListener listener) Adds a listener to the specified node.
void	addNodeListener(String nodeName, NodeEventListener listener) Adds a listener to the specified node.
Configuration	createConfiguration(Class configurationType) This method is the primary interface to create new instances of Configuration Objects.
Configuration	fetchConfiguration(String configurationName) Returns a Configuration object that contains all of the configuration data in the ConfigurationDocument located by configurationName.
Node	fetchNode(String nodeName) Traverses the internal node hierachy and returns the named node
Configuration	fetchWritableConfiguration(String configurationName) Returns a Configuration object that contains all of the configuration data in the ConfigurationDocument located by configurationName.
private String	getRemainingTokens(StringTokenizer tokenizer) Assembles the remaining tokens into a string, used for error messages.
private void	initialize(ConfigurationDocument rootConfigurationDoc) Reads a LinkNodeConfiguration from the rootConfigurationDoc and uses the configured LinkNodeFactoryClass to create a new Node that is then set as the root node for the ConfigurationService.
boolean	nodeExists(String nodeName) Returns true if the node exists in the configuration repository and false if it does not exist.
private Node	recursiveNodeTraversal(Node node, StringTokenizer tokenizer) Returns the Node found by recursively fetching the next node name from tokenizer and scaling the node tree.
private void	recursiveStoreConfiguration(Node node, Configuration config, StringTokenizer tokenizer) Traverses down the node adding the sub-nodes.
private boolean	recursiveTraverseNodeTreeForNodeExists(Node node, StringTokenizer tokenizer) Returns true if a node is found by recursively tokenizing the configurationName by '/' characters and scaling the node tree.
void	storeConfiguration(String configurationName, Configuration config) The storeConfiguration method persists configuration data contained in config to the underlying ConfigurationDocument named by configurationName.
private Node	traverseNodeTree(String configurationName) Returns the Node found by recursively tokenizing the configurationName by '/' characters and scaling the node tree.
private boolean	traverseNodeTreeForNodeExists(String configurationName) Returns true if a node is found by recursively tokenizing the configurationName by '/' characters and scaling the node tree.

Methods inherited from class java.lang.Object

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

Field Detail

log

private org.apache.commons.logging.Log log

Provides a handle to Apache-commons logger

rootNode

private Node rootNode

Handle to the root node used by this ConfigurationService.

cache

private ConfigurationCache cache

Cache storing previously accessed configuration objects.

Since:

carbon 1.1

Constructor Detail

DefaultRootConfigurationService

protected DefaultRootConfigurationService(ConfigurationDocument configurationDocument)

protected constructor prevents direct instantiation by classes other than the DefaultConfigurationServiceFactory but does not prevent extension.

Parameters:

configurationDocument - the configuration document being loaded

Method Detail

fetchConfiguration

public Configuration fetchConfiguration(String configurationName)

Description copied from interface: ConfigurationService

Returns a Configuration object that contains all of the configuration data in the ConfigurationDocument located by configurationName.

The returned configuration may be a shared object that is read-only. If it is, the configuration's writable flag is set to false and exceptions will be thrown if an attempt is made to modify the object.

Specified by:

fetchConfiguration in interface ConfigurationService

Parameters:

configurationName - The name of the requested configuration

Returns:

Configuration object that may be used to access discrete configuration data.

See Also:

ConfigurationService.fetchConfiguration(java.lang.String)

fetchWritableConfiguration

public Configuration fetchWritableConfiguration(String configurationName)

Description copied from interface: ConfigurationService

Returns a Configuration object that contains all of the configuration data in the ConfigurationDocument located by configurationName.

The returned configuration is a mutable object and not thread-safe. All access to this object should be in a single threaded or synchronized context. To commit the changes that have been made to this object use the storeConfiguration method.

Specified by:

fetchWritableConfiguration in interface ConfigurationService

Parameters:

configurationName - The name of the requested configuration

Returns:

Configuration object that may be used to access discrete configuration data.

See Also:

ConfigurationService.fetchWritableConfiguration(java.lang.String)

storeConfiguration

public void storeConfiguration(String configurationName,
                               Configuration config)
                        throws ConfigurationStoreException

Description copied from interface: ConfigurationService

The storeConfiguration method persists configuration data contained in config to the underlying ConfigurationDocument named by configurationName. If the ConfigurationDocument does not exist, it is created along with all of its parent Nodes.

Specified by:

storeConfiguration in interface ConfigurationService

Parameters:

configurationName - The name of the Configuration Document where the configuration data should be stored.

config - Configuration data to be persisted to the underlying data store.

Throws:

ConfigurationStoreException - data can not be written to the backing store.

See Also:

ConfigurationService.storeConfiguration(java.lang.String, org.sape.carbon.core.config.Configuration)

createConfiguration

public Configuration createConfiguration(Class configurationType)

Description copied from interface: ConfigurationService

This method is the primary interface to create new instances of Configuration Objects. This method is capable of creating an empty configuration object for an interface that extends the Configuration interface.

Specified by:

createConfiguration in interface ConfigurationService

Parameters:

configurationType - The Class of the configuration type to be created

Returns:

an empty instance of a configuration object implementing the provided class.

See Also:

ConfigurationService.createConfiguration(java.lang.Class)

fetchNode

public Node fetchNode(String nodeName)
               throws NodeNotFoundException

Description copied from interface: ConfigurationService

Traverses the internal node hierachy and returns the named node

Specified by:

fetchNode in interface ConfigurationService

Parameters:

nodeName - the '/' delimeted path to the node

Returns:

The node specifed by nodeName.

Throws:

NodeNotFoundException - when the cannot be found.

See Also:

ConfigurationService.fetchNode(java.lang.String)

addNodeListener

public void addNodeListener(String nodeName,
                            NodeEventListener listener)
                     throws NodeNotFoundException

Description copied from interface: ConfigurationService

Adds a listener to the specified node.

Specified by:

addNodeListener in interface ConfigurationService

Parameters:

nodeName - the '/' delimeted path to the node

listener - the object that will be notified of NodeEvents

Throws:

NodeNotFoundException - if nodeName does not exist

See Also:

ConfigurationService.addNodeListener(String, NodeEventListener)

addNodeListener

public void addNodeListener(String nodeName,
                            ConfigurationEventListener listener)
                     throws NodeNotFoundException

Description copied from interface: ConfigurationService

Adds a listener to the specified node.

Specified by:

addNodeListener in interface ConfigurationService

Parameters:

nodeName - the '/' delimeted path to the node

listener - the object that will be notified of NodeEvents

Throws:

NodeNotFoundException - if nodeName does not exist

See Also:

ConfigurationService.addNodeListener(String, ConfigurationEventListener)

nodeExists

public boolean nodeExists(String nodeName)

Description copied from interface: ConfigurationService

Returns true if the node exists in the configuration repository and false if it does not exist. This is meant to be an alternative to getting Node not found exceptions when you have nodes that aren't required.

Specified by:

nodeExists in interface ConfigurationService

Parameters:

nodeName - the '/' delimeted path to the node

Returns:

if the node exists

See Also:

ConfigurationService.nodeExists(java.lang.String)

initialize

private void initialize(ConfigurationDocument rootConfigurationDoc)

Reads a LinkNodeConfiguration from the rootConfigurationDoc and uses the configured LinkNodeFactoryClass to create a new Node that is then set as the root node for the ConfigurationService.

Parameters:

rootConfigurationDoc - Contains data required to initialize this instance of ConfigurationService and its root node.

See Also:

LinkNode, LinkNodeConfiguration

traverseNodeTree

private Node traverseNodeTree(String configurationName)
                       throws NodeNotFoundException

Returns the Node found by recursively tokenizing the configurationName by '/' characters and scaling the node tree.

Parameters:

configurationName - The full logical name of the configuration to be fetched, such as /nodeA/nodeB/configuration1.

Returns:

The node corresponding to configurationName.

Throws:

NodeNotFoundException - when a node can not be fetched.

recursiveNodeTraversal

private Node recursiveNodeTraversal(Node node,
                                    StringTokenizer tokenizer)
                             throws NodeNotFoundException

Returns the Node found by recursively fetching the next node name from tokenizer and scaling the node tree.

Parameters:

node - the current parent node in the node traversal.

tokenizer - The StringTokenizer used to access the next node to be traversed.

Returns:

The node corresponding to the final token in tokenizer.

Throws:

NodeNotFoundException - when a node can not be fetched.

traverseNodeTreeForNodeExists

private boolean traverseNodeTreeForNodeExists(String configurationName)

Returns true if a node is found by recursively tokenizing the configurationName by '/' characters and scaling the node tree.

Parameters:

configurationName - The full logical name of the configuration to be fetched, such as /nodeA/nodeB/configuration1.

Returns:

true if the node exists or false otherwise

Since:

carbon 1.1

recursiveTraverseNodeTreeForNodeExists

private boolean recursiveTraverseNodeTreeForNodeExists(Node node,
                                                       StringTokenizer tokenizer)

Returns true if a node is found by recursively tokenizing the configurationName by '/' characters and scaling the node tree.

Parameters:

node - the current parent node in the node traversal.

tokenizer - The StringTokenizer used to access the next node to be traversed.

Returns:

true if the node exists or false otherwise

Since:

carbon 1.1

recursiveStoreConfiguration

private void recursiveStoreConfiguration(Node node,
                                         Configuration config,
                                         StringTokenizer tokenizer)
                                  throws NodeCreationException,
                                         NodeIOException,
                                         ConfigurationFormatException

Traverses down the node adding the sub-nodes.

Parameters:

node - the node to add the children to

config - configuration to store

tokenizer - tokenizer of the full node name

Throws:

NodeCreationException - indicates an error creating the node

NodeIOException - indicates an error reading the node

ConfigurationFormatException - indicates an error in format of the configuration

getRemainingTokens

private String getRemainingTokens(StringTokenizer tokenizer)

Assembles the remaining tokens into a string, used for error messages.

Parameters:

tokenizer - the tokenizer to pull tokens from

Returns:

the remaining tokens delimited by Node.DELIMITER