/*
 * 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.configuration2.builder.combined;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

import org.apache.commons.configuration2.FileBasedConfiguration;
import org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.ReloadingFileBasedConfigurationBuilder;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.reloading.CombinedReloadingController;
import org.apache.commons.configuration2.reloading.ReloadingController;
import org.apache.commons.configuration2.reloading.ReloadingControllerSupport;

A specialized MultiFileConfigurationBuilder implementation which adds support for reloading.

This class - as its super class - allows operating on multiple configuration files whose file names are determined using a file name pattern and a ConfigurationInterpolator object. It provides the following additional features:

  • Configuration builder for managed configurations have reloading support. So reloading is possible for all configuration sources loaded by this builder instance.
  • A ReloadingController is provided which can be used to trigger reload checks on all managed configurations.

Although this builder manages an arbitrary number of child configurations, to clients only a single configuration is visible - the one selected by the evaluation of the file name pattern. Builder reset notifications triggered by the reloading mechanism do not really take this fact into account; they are not limited to the currently selected child configuration, but occur for each of the managed configuration.

Type parameters:
  • <T> – the concrete type of Configuration objects created by this builder
Since:2.0
/** * <p> * A specialized {@code MultiFileConfigurationBuilder} implementation which adds * support for reloading. * </p> * <p> * This class - as its super class - allows operating on multiple configuration * files whose file names are determined using a file name pattern and a * {@code ConfigurationInterpolator} object. It provides the following * additional features: * </p> * <ul> * <li>Configuration builder for managed configurations have reloading support. * So reloading is possible for all configuration sources loaded by this builder * instance.</li> * <li>A {@link ReloadingController} is provided which can be used to trigger * reload checks on all managed configurations.</li> * </ul> * <p> * Although this builder manages an arbitrary number of child configurations, to * clients only a single configuration is visible - the one selected by the * evaluation of the file name pattern. Builder reset notifications triggered by * the reloading mechanism do not really take this fact into account; they are * not limited to the currently selected child configuration, but occur for each * of the managed configuration. * </p> * * @since 2.0 * @param <T> the concrete type of {@code Configuration} objects created by this * builder */
public class ReloadingMultiFileConfigurationBuilder<T extends FileBasedConfiguration> extends MultiFileConfigurationBuilder<T> implements ReloadingControllerSupport {
The reloading controller used by this builder.
/** The reloading controller used by this builder. */
private final ReloadingController reloadingController = createReloadingController();
Creates a new instance of ReloadingMultiFileConfigurationBuilder and sets initialization parameters and a flag whether initialization failures should be ignored.
Params:
  • resCls – the result configuration class
  • params – a map with initialization parameters
  • allowFailOnInit – a flag whether initialization errors should be ignored
Throws:
/** * Creates a new instance of {@code ReloadingMultiFileConfigurationBuilder} * and sets initialization parameters and a flag whether initialization * failures should be ignored. * * @param resCls the result configuration class * @param params a map with initialization parameters * @param allowFailOnInit a flag whether initialization errors should be * ignored * @throws IllegalArgumentException if the result class is <b>null</b> */
public ReloadingMultiFileConfigurationBuilder(final Class<T> resCls, final Map<String, Object> params, final boolean allowFailOnInit) { super(resCls, params, allowFailOnInit); }
Creates a new instance of ReloadingMultiFileConfigurationBuilder and sets initialization parameters.
Params:
  • resCls – the result configuration class
  • params – a map with initialization parameters
Throws:
/** * Creates a new instance of {@code ReloadingMultiFileConfigurationBuilder} * and sets initialization parameters. * * @param resCls the result configuration class * @param params a map with initialization parameters * @throws IllegalArgumentException if the result class is <b>null</b> */
public ReloadingMultiFileConfigurationBuilder(final Class<T> resCls, final Map<String, Object> params) { super(resCls, params); }
Creates a new instance of ReloadingMultiFileConfigurationBuilder without setting initialization parameters.
Params:
  • resCls – the result configuration class
Throws:
/** * Creates a new instance of {@code ReloadingMultiFileConfigurationBuilder} * without setting initialization parameters. * * @param resCls the result configuration class * @throws IllegalArgumentException if the result class is <b>null</b> */
public ReloadingMultiFileConfigurationBuilder(final Class<T> resCls) { super(resCls); }
{@inheritDoc} This implementation returns a special ReloadingController that delegates to the reloading controllers of the managed builders created so far.
/** * {@inheritDoc} This implementation returns a special * {@code ReloadingController} that delegates to the reloading controllers * of the managed builders created so far. */
@Override public ReloadingController getReloadingController() { return reloadingController; }
{@inheritDoc} This implementation returns a file-based configuration builder with reloading support.
/** * {@inheritDoc} This implementation returns a file-based configuration * builder with reloading support. */
@Override protected FileBasedConfigurationBuilder<T> createManagedBuilder( final String fileName, final Map<String, Object> params) throws ConfigurationException { return new ReloadingFileBasedConfigurationBuilder<>(getResultClass(), params, isAllowFailOnInit()); }
Creates the reloading controller used by this builder. This method creates a specialized CombinedReloadingController which operates on the reloading controllers of the managed builders created so far.
Returns:the newly created ReloadingController
/** * Creates the reloading controller used by this builder. This method * creates a specialized {@link CombinedReloadingController} which operates * on the reloading controllers of the managed builders created so far. * * @return the newly created {@code ReloadingController} */
private ReloadingController createReloadingController() { final Set<ReloadingController> empty = Collections.emptySet(); return new CombinedReloadingController(empty) { @Override public Collection<ReloadingController> getSubControllers() { final Collection<FileBasedConfigurationBuilder<T>> builders = getManagedBuilders().values(); final Collection<ReloadingController> controllers = new ArrayList<>(builders.size()); for (final FileBasedConfigurationBuilder<T> b : builders) { controllers.add(((ReloadingControllerSupport) b) .getReloadingController()); } return controllers; } }; } }