org.sape.carbon.services.config.jar
Class JarConfigurationDocument

java.lang.Object
  |
  +--org.sape.carbon.core.config.node.AbstractNode
        |
        +--org.sape.carbon.core.config.node.AbstractConfigurationDocument
              |
              +--org.sape.carbon.services.config.jar.JarConfigurationDocument

All Implemented Interfaces:

ConfigurationDocument, Node

public class JarConfigurationDocument

extends AbstractConfigurationDocument

Implementation of ConfigurationDocument using entries within jar files as the backing datastore.

This implementation does not maintain an open jar file. It will open the jar file only when it needs to read or write and close it when it is done.

Copyright 2002 Sapient

Since:

carbon 1.0

Version:

$Revision: 1.2 $($Author: dvoet $ / $Date: 2003/05/05 21:21:09 $)

Author:

Douglas Voet, April 2002

Field Summary

private EnhancedJarFile	currentOpenJar Holds the enhanced jar being wrapped.
private String	jarEntryName Name of the jar entry.
private File	jarFile Holds the simple reference to the jar file.
private boolean	jarOpenForRead flags if the jar is open for read.
private org.apache.commons.logging.Log	log Provides a handle to Apache-commons logger
private ReadWriteLock	readWriteLock Holds a read/write lock for this jar.

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

JarConfigurationDocument(Node parent, String name, ConfigurationFormatService formatter, ReadWriteLock readWriteLock, File jarFile, String jarEntryName)
Constructor for JarConfigurationDocument.

Method Summary

protected boolean	backingDataExists() Method called from the refresh method to see if the backing data still exists.
protected void	closeInputStream(InputStream in) Closes the input stream.
private void	closeJar() Closes the jar file if it is open, releasing the lock based upon how it was opened.
protected void	closeOutputStream(OutputStream out) Closes the output stream.
protected void	destroyBackingData() This method is called by remove to destroy the data backing this node in the data source.
protected InputStream	openInputStream() This method should be overridden by classes implementing ConfigurationDocuments for specific data stores.
private EnhancedJarFile	openJar(boolean forRead) Opens the jar file.
protected OutputStream	openOutputStream() This method should be overridden by classes implementing ConfigurationDocuments for specific data stores.

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

addNestedConfigurationDocument, getAllChildNames, getFormatService, getNestedNodeFactory, issueNodeModifiedEvent, loadChild, notifyNestedDocuments, readConfiguration, refresh, remove, writeChildReferences, writeConfiguration

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

addNodeListener, addNodeListener, addNodeListener, containsChild, fetchChild, fetchChildren, getAbsoluteName, getAddOrLoadChildLock, getAllowsChildren, getName, getParent, getReadOrAlterNodeLock, isRemoved, 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, isRemoved

Field Detail

log

private org.apache.commons.logging.Log log

Provides a handle to Apache-commons logger

jarFile

private File jarFile

Holds the simple reference to the jar file.

jarEntryName

private String jarEntryName

Name of the jar entry.

currentOpenJar

private EnhancedJarFile currentOpenJar

Holds the enhanced jar being wrapped.

jarOpenForRead

private boolean jarOpenForRead

flags if the jar is open for read.

readWriteLock

private final ReadWriteLock readWriteLock

Holds a read/write lock for this jar.

Constructor Detail

JarConfigurationDocument

public JarConfigurationDocument(Node parent,
                                String name,
                                ConfigurationFormatService formatter,
                                ReadWriteLock readWriteLock,
                                File jarFile,
                                String jarEntryName)

Constructor for JarConfigurationDocument.

Parameters:

parent - the parent node of the configuration document

name - name of the configuration document

formatter - formatter to use on the document

readWriteLock - lock for the document

jarFile - jarfile the document is wrapping

jarEntryName - entry inside the jarfile

Method Detail

openInputStream

protected InputStream openInputStream()
                               throws IOException

Description copied from class: AbstractConfigurationDocument

This method should be overridden by classes implementing ConfigurationDocuments for specific data stores. The returned InputStream should be a stream of data that can be read by the ConfigurationFormatService and converted to a Configuration object.

This method is called by readConfiguration.

Specified by:

openInputStream in class AbstractConfigurationDocument

Returns:

InputStream the InputStream from which to read the Configuration object within this ConfigurationDocument

IOException

See Also:

AbstractConfigurationDocument.openInputStream()

closeInputStream

protected void closeInputStream(InputStream in)
                         throws IOException

Description copied from class: AbstractConfigurationDocument

Closes the input stream.

Overrides:

closeInputStream in class AbstractConfigurationDocument

Parameters:

in - the stream to open

IOException

See Also:

AbstractConfigurationDocument.closeInputStream(InputStream)

openOutputStream

protected OutputStream openOutputStream()
                                 throws IOException

Description copied from class: AbstractConfigurationDocument

This method should be overridden by classes implementing ConfigurationDocuments for specific data stores. The returned OutputStream should be a stream of data that can be written to by the ConfigurationFormatService.

This method is called by writeConfiguration.

Specified by:

openOutputStream in class AbstractConfigurationDocument

Returns:

OutputStream the OutputStream to which to write the Configuration object within this ConfigurationDocument

IOException

See Also:

AbstractConfigurationDocument.openOutputStream()

closeOutputStream

protected void closeOutputStream(OutputStream out)
                          throws IOException

Description copied from class: AbstractConfigurationDocument

Closes the output stream.

Overrides:

closeOutputStream in class AbstractConfigurationDocument

Parameters:

out - the stream to close

IOException

See Also:

AbstractConfigurationDocument.closeOutputStream(OutputStream)

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()

openJar

private EnhancedJarFile openJar(boolean forRead)
                         throws IOException

Opens the jar file. Based on the boolean value of forRead, a read or a write lock will be acquired.

Parameters:

forRead - if true a read lock will be acquired, if false, a write lock will be acquired

Returns:

the opened jar file

Throws:

IOException - indicates an error opening the jar

closeJar

private void closeJar()
               throws IOException

Closes the jar file if it is open, releasing the lock based upon how it was opened.

Throws:

IOException - indicates an error closing the jar