/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.commons.configuration.builder.combined;
import java.util.Arrays;
import java.util.Collection;
import org.apache.commons.configuration.CombinedConfiguration;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.builder.BasicBuilderParameters;
import org.apache.commons.configuration.builder.BasicConfigurationBuilder;
import org.apache.commons.configuration.builder.BuilderParameters;
/**
* <p>
* A specialized {@code ConfigurationBuilderProvider} implementation which deals
* with combined configuration builders.
* </p>
* <p>
* This class is used to support {@code <configuration>} elements in
* configuration definition files. The provider creates another
* {@link CombinedConfigurationBuilder} which inherits some of the properties
* from its parent builder.
* </p>
*
* @version $Id: CombinedConfigurationBuilderProvider.java 1502845 2013-07-13 19:27:19Z oheger $
* @since 2.0
*/
public class CombinedConfigurationBuilderProvider extends
BaseConfigurationBuilderProvider
{
/** Constant for the name of the supported builder class. */
private static final String BUILDER_CLASS =
"org.apache.commons.configuration.builder.combined.CombinedConfigurationBuilder";
/** Constant for the name of the supported reloading builder class. */
private static final String RELOADING_BUILDER_CLASS =
"org.apache.commons.configuration.builder.combined.ReloadingCombinedConfigurationBuilder";
/** Constant for the name of the supported configuration class. */
private static final String CONFIGURATION_CLASS =
"org.apache.commons.configuration.CombinedConfiguration";
/** Constant for the combined configuration builder parameters class. */
private static final String COMBINED_PARAMS =
"org.apache.commons.configuration.builder.combined.CombinedBuilderParametersImpl";
/** Constant for the name of the file-based builder parameters class. */
private static final String FILE_PARAMS =
"org.apache.commons.configuration.builder.FileBasedBuilderParametersImpl";
/**
* Creates a new instance of {@code CombinedConfigurationBuilderProvider}.
*/
public CombinedConfigurationBuilderProvider()
{
super(BUILDER_CLASS, RELOADING_BUILDER_CLASS, CONFIGURATION_CLASS,
Arrays.asList(COMBINED_PARAMS, FILE_PARAMS));
}
/**
* {@inheritDoc} This implementation creates the result builder object
* directly, not using reflection. (The reflection-based approach of the
* base class does not work here because a combined configuration builder
* has constructors with a different signature.) It also performs some
* additional initializations.
*/
@Override
protected BasicConfigurationBuilder<? extends Configuration> createBuilder(
ConfigurationDeclaration decl, Collection<BuilderParameters> params)
throws Exception
{
CombinedConfigurationBuilder builder;
if (decl.isReload())
{
builder = new ReloadingCombinedConfigurationBuilder();
}
else
{
builder = new CombinedConfigurationBuilder();
}
decl.getConfigurationBuilder().initChildEventListeners(builder);
return builder;
}
/**
* {@inheritDoc} This implementation pre-fills basic parameters from the
* basic properties of the parent builder's result configuration.
*/
@Override
protected void initializeParameterObjects(ConfigurationDeclaration decl,
Collection<BuilderParameters> params) throws Exception
{
// we know that the first object is the combined builder parameters
// object
BasicBuilderParameters basicParams =
(BasicBuilderParameters) params.iterator().next();
setUpBasicParameters(decl.getConfigurationBuilder()
.getConfigurationUnderConstruction(), basicParams);
// now properties set explicitly can be overridden
super.initializeParameterObjects(decl, params);
}
/**
* Populates the specified parameters object with properties from the given
* configuration. This method is used to set default values for basic
* properties based on the result configuration of the parent builder.
*
* @param config the configuration whose properties are to be copied
* @param params the target parameters object
*/
private static void setUpBasicParameters(CombinedConfiguration config,
BasicBuilderParameters params)
{
params.setListDelimiterHandler(config.getListDelimiterHandler())
.setLogger(config.getLogger())
.setThrowExceptionOnMissing(config.isThrowExceptionOnMissing());
}
}