package org.codehaus.plexus.configuration;
import org.codehaus.plexus.configuration.xml.XmlPlexusConfiguration;
/*
* Copyright 2001-2006 Codehaus Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @todo This merger explicity uses the XML implementation of the plexus configuration but
* it must work for configurations coming from any source.
*/
public class PlexusConfigurationMerger
{
// -----------------------------------+-----------------------------------------------------------------
// E L E M E N T |
// -----------------------------------+-----------------------------------------------------------------
// load-on-start | user
// -----------------------------------+-----------------------------------------------------------------
// system-properties | user
// -----------------------------------+-----------------------------------------------------------------
// configurations-directory | user
// -----------------------------------+-----------------------------------------------------------------
// logging | user wins
// -----------------------------------+-----------------------------------------------------------------
// component-repository | user wins
// -----------------------------------+-----------------------------------------------------------------
// resources | user wins, but system resources show through
// -----------------------------------+-----------------------------------------------------------------
// component-manager-manager | user wins, but system resources show through
// -----------------------------------+-----------------------------------------------------------------
// component-discoverer-manager | user wins, but system resources show through
// -----------------------------------+-----------------------------------------------------------------
// component-factory-manager | user wins, but system resources show through
// -----------------------------------+-----------------------------------------------------------------
// lifecycle-handler-manager | user wins, but system lifecycles show through
// -----------------------------------+-----------------------------------------------------------------
// component-composer-manager | user wins, but system lifecycles show through
// -----------------------------------+-----------------------------------------------------------------
// components | user
// -----------------------------------+-----------------------------------------------------------------
public static PlexusConfiguration merge( PlexusConfiguration user, PlexusConfiguration system )
{
PlexusConfiguration mergedConfiguration = new XmlPlexusConfiguration( "plexus" );
// ----------------------------------------------------------------------
// Load on start
// ----------------------------------------------------------------------
PlexusConfiguration loadOnStart = user.getChild( "load-on-start" );
if ( loadOnStart.getChildCount() != 0 )
{
mergedConfiguration.addChild( loadOnStart );
}
// ----------------------------------------------------------------------
// System properties
// ----------------------------------------------------------------------
PlexusConfiguration systemProperties = user.getChild( "system-properties" );
if ( systemProperties.getChildCount() != 0 )
{
mergedConfiguration.addChild( systemProperties );
}
// ----------------------------------------------------------------------
// Configurations directory
// ----------------------------------------------------------------------
PlexusConfiguration[] configurationsDirectories = user.getChildren( "configurations-directory" );
if ( configurationsDirectories.length != 0 )
{
for ( int i = 0; i < configurationsDirectories.length; i++ )
{
mergedConfiguration.addChild( configurationsDirectories[i] );
}
}
// ----------------------------------------------------------------------
// Logging
// ----------------------------------------------------------------------
PlexusConfiguration logging = user.getChild( "logging" );
if ( logging.getChildCount() != 0 )
{
mergedConfiguration.addChild( logging );
}
else
{
mergedConfiguration.addChild( system.getChild( "logging" ) );
}
// ----------------------------------------------------------------------
// Container initialization phases
// ----------------------------------------------------------------------
mergedConfiguration.addChild( system.getChild( "container-initialization") );
mergedConfiguration.addChild( system.getChild( "component-lookup-manager") );
// ----------------------------------------------------------------------
// Component repository
// ----------------------------------------------------------------------
PlexusConfiguration componentRepository = user.getChild( "component-repository" );
if ( componentRepository.getChildCount() != 0 )
{
mergedConfiguration.addChild( componentRepository );
}
else
{
mergedConfiguration.addChild( system.getChild( "component-repository" ) );
}
// ----------------------------------------------------------------------
// Resources
// ----------------------------------------------------------------------
copyResources( system, mergedConfiguration );
copyResources( user, mergedConfiguration );
// ----------------------------------------------------------------------
// Component manager manager
// ----------------------------------------------------------------------
PlexusConfiguration componentManagerManager = user.getChild( "component-manager-manager" );
if ( componentManagerManager.getChildCount() != 0 )
{
mergedConfiguration.addChild( componentManagerManager );
copyComponentManagers( system.getChild( "component-manager-manager" ), componentManagerManager );
}
else
{
mergedConfiguration.addChild( system.getChild( "component-manager-manager" ) );
}
// ----------------------------------------------------------------------
// Component discoverer manager
// ----------------------------------------------------------------------
PlexusConfiguration componentDiscovererManager = user.getChild( "component-discoverer-manager" );
if ( componentDiscovererManager.getChildCount() != 0 )
{
mergedConfiguration.addChild( componentDiscovererManager );
copyComponentDiscoverers( system.getChild( "component-discoverer-manager" ), componentDiscovererManager );
}
else
{
mergedConfiguration.addChild( system.getChild( "component-discoverer-manager" ) );
}
// ----------------------------------------------------------------------
// Component factory manager
// ----------------------------------------------------------------------
PlexusConfiguration componentFactoryManager = user.getChild( "component-factory-manager" );
if ( componentFactoryManager.getChildCount() != 0 )
{
mergedConfiguration.addChild( componentFactoryManager );
copyComponentFactories( system.getChild( "component-factory-manager" ), componentFactoryManager );
}
else
{
mergedConfiguration.addChild( system.getChild( "component-factory-manager" ) );
}
// ----------------------------------------------------------------------
// Lifecycle handler managers
// ----------------------------------------------------------------------
PlexusConfiguration lifecycleHandlerManager = user.getChild( "lifecycle-handler-manager" );
if ( lifecycleHandlerManager.getChildCount() != 0 )
{
mergedConfiguration.addChild( lifecycleHandlerManager );
copyLifecycles( system.getChild( "lifecycle-handler-manager" ), lifecycleHandlerManager );
}
else
{
mergedConfiguration.addChild( system.getChild( "lifecycle-handler-manager" ) );
}
// ----------------------------------------------------------------------
// Component factory manager
// ----------------------------------------------------------------------
PlexusConfiguration componentComposerManager = user.getChild( "component-composer-manager" );
if ( componentComposerManager.getChildCount() != 0 )
{
mergedConfiguration.addChild( componentComposerManager );
copyComponentComposers( system.getChild( "component-composer-manager" ), componentComposerManager );
}
else
{
mergedConfiguration.addChild( system.getChild( "component-composer-manager" ) );
}
// ----------------------------------------------------------------------
// Components
// ----------------------------------------------------------------------
// We grab the system components first and then add the user defined
// components so that user defined components will win. When component
// descriptors are processed the last definition wins because the component
// descriptors are stored in a Map in the component repository.
// ----------------------------------------------------------------------
PlexusConfiguration components = system.getChild( "components" );
mergedConfiguration.addChild( components );
copyComponents( user.getChild( "components" ), components );
return mergedConfiguration;
}
private static void copyResources( PlexusConfiguration source, PlexusConfiguration destination )
{
PlexusConfiguration handlers[] = source.getChild( "resources" ).getChildren();
PlexusConfiguration dest = destination.getChild( "resources" );
for ( int i = 0; i < handlers.length; i++ )
{
dest.addChild( handlers[i] );
}
}
private static void copyComponentManagers( PlexusConfiguration source, PlexusConfiguration destination )
{
try
{
PlexusConfiguration id = destination.getChild( "default-component-manager-id" );
String sid = source.getChild( "default-component-manager-id" ).getValue();
if ( id.getValue() == null )
{
id.setValue( sid );
}
}
catch ( PlexusConfigurationException e )
{
// do nothing
}
PlexusConfiguration handlers[] = source.getChild( "component-managers" ).getChildren( "component-manager" );
PlexusConfiguration dest = destination.getChild( "component-managers" );
for ( int i = 0; i < handlers.length; i++ )
{
dest.addChild( handlers[i] );
}
}
private static void copyComponentDiscoverers( PlexusConfiguration source, PlexusConfiguration destination )
{
PlexusConfiguration handlers[] = source.getChild( "component-discoverers" ).getChildren( "component-discoverer" );
PlexusConfiguration dest = destination.getChild( "component-discoverers" );
for ( int i = 0; i < handlers.length; i++ )
{
dest.addChild( handlers[i] );
}
}
private static void copyComponentFactories( PlexusConfiguration source, PlexusConfiguration destination )
{
PlexusConfiguration handlers[] = source.getChild( "component-factories" ).getChildren( "component-factory" );
PlexusConfiguration dest = destination.getChild( "component-factories" );
for ( int i = 0; i < handlers.length; i++ )
{
dest.addChild( handlers[i] );
}
}
private static void copyComponentComposers( PlexusConfiguration source, PlexusConfiguration destination )
{
try
{
PlexusConfiguration id = destination.getChild( "default-component-composer-id" );
String sid = source.getChild( "default-component-composer-id" ).getValue();
if ( id.getValue() == null )
{
id.setValue( sid );
}
}
catch ( PlexusConfigurationException e )
{
// do nothing
}
PlexusConfiguration composers[] = source.getChild( "component-composers" ).getChildren( "component-composer" );
PlexusConfiguration dest = destination.getChild( "component-composers" );
for ( int i = 0; i < composers.length; i++ )
{
dest.addChild( composers[i] );
}
}
private static void copyLifecycles( PlexusConfiguration source, PlexusConfiguration destination )
{
PlexusConfiguration handlers[] = source.getChild( "lifecycle-handlers" ).getChildren( "lifecycle-handler" );
PlexusConfiguration dest = destination.getChild( "lifecycle-handlers" );
for ( int i = 0; i < handlers.length; i++ )
{
dest.addChild( handlers[i] );
}
}
private static void copyComponents( PlexusConfiguration source, PlexusConfiguration destination )
{
PlexusConfiguration components[] = source.getChildren( "component" );
for ( int i = 0; i < components.length; i++ )
{
destination.addChild( components[i] );
}
}
}