    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *     http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.configuration2;
    019
    020import java.util.ArrayList;
    021import java.util.Collection;
    022import java.util.Iterator;
    023import java.util.LinkedHashMap;
    024import java.util.List;
    025import java.util.Map;
    026
    027import org.apache.commons.configuration2.ex.ConfigurationRuntimeException;
    028
    029/**
    030 * Basic configuration class. Stores the configuration data but does not provide any load or save functions. If you want
    031 * to load your Configuration from a file use PropertiesConfiguration or XmlConfiguration.
    032 *
    033 * This class extends normal Java properties by adding the possibility to use the same key many times concatenating the
    034 * value strings instead of overwriting them.
    035 */
    036public class BaseConfiguration extends AbstractConfiguration implements Cloneable {
    037    /** Stores the configuration key-value pairs */
    038    private Map<String, Object> store = new LinkedHashMap<>();
    039
    040    /**
    041     * Adds a key/value pair to the map. This routine does no magic morphing. It ensures the keylist is maintained
    042     *
    043     * @param key key to use for mapping
    044     * @param value object to store
    045     */
    046    @Override
    047    protected void addPropertyDirect(final String key, final Object value) {
    048        final Object previousValue = getPropertyInternal(key);
    049
    050        if (previousValue == null) {
    051            store.put(key, value);
    052        } else if (previousValue instanceof List) {
    053            // safe to case because we have created the lists ourselves
    054            @SuppressWarnings("unchecked")
    055            final List<Object> valueList = (List<Object>) previousValue;
    056            // the value is added to the existing list
    057            valueList.add(value);
    058        } else {
    059            // the previous value is replaced by a list containing the previous value and the new value
    060            final List<Object> list = new ArrayList<>();
    061            list.add(previousValue);
    062            list.add(value);
    063
    064            store.put(key, list);
    065        }
    066    }
    067
    068    @Override
    069    protected void clearInternal() {
    070        store.clear();
    071    }
    072
    073    /**
    074     * Clear a property in the configuration.
    075     *
    076     * @param key the key to remove along with corresponding value.
    077     */
    078    @Override
    079    protected void clearPropertyDirect(final String key) {
    080        store.remove(key);
    081    }
    082
    083    /**
    084     * Creates a copy of this object. This implementation will create a deep clone, i.e. the map that stores the properties
    085     * is cloned, too. So changes performed at the copy won't affect the original and vice versa.
    086     *
    087     * @return the copy
    088     * @since 1.3
    089     */
    090    @Override
    091    public Object clone() {
    092        try {
    093            final BaseConfiguration copy = (BaseConfiguration) super.clone();
    094            cloneStore(copy);
    095            copy.cloneInterpolator(this);
    096
    097            return copy;
    098        } catch (final CloneNotSupportedException cex) {
    099            // should not happen
    100            throw new ConfigurationRuntimeException(cex);
    101        }
    102    }
    103
    104    /**
    105     * Clones the internal map with the data of this configuration.
    106     *
    107     * @param copy the copy created by the {@code clone()} method
    108     * @throws CloneNotSupportedException if the map cannot be cloned
    109     */
    110    private void cloneStore(final BaseConfiguration copy) throws CloneNotSupportedException {
    111        // This is safe because the type of the map is known
    112        @SuppressWarnings("unchecked")
    113        final Map<String, Object> clonedStore = (Map<String, Object>) ConfigurationUtils.clone(store);
    114        copy.store = clonedStore;
    115
    116        // Handle collections in the map; they have to be cloned, too
    117        store.forEach((k, v) -> {
    118            if (v instanceof Collection) {
    119                // This is safe because the collections were created by ourselves
    120                @SuppressWarnings("unchecked")
    121                final Collection<String> strList = (Collection<String>) v;
    122                copy.store.put(k, new ArrayList<>(strList));
    123            }
    124        });
    125    }
    126
    127    /**
    128     * check if the configuration contains the key
    129     *
    130     * @param key the configuration key
    131     *
    132     * @return {@code true} if Configuration contain given key, {@code false} otherwise.
    133     */
    134    @Override
    135    protected boolean containsKeyInternal(final String key) {
    136        return store.containsKey(key);
    137    }
    138
    139    /**
    140     * Tests whether this configuration contains one or more matches to this value. This operation stops at first
    141     * match but may be more expensive than the containsKey method.
    142     * @since 2.11.0
    143     */
    144    @Override
    145    protected boolean containsValueInternal(final Object value) {
    146        return store.containsValue(value);
    147    }
    148
    149    /**
    150     * Gets the list of the keys contained in the configuration repository.
    151     *
    152     * @return An Iterator.
    153     */
    154    @Override
    155    protected Iterator<String> getKeysInternal() {
    156        return store.keySet().iterator();
    157    }
    158
    159    /**
    160     * Read property from underlying map.
    161     *
    162     * @param key key to use for mapping
    163     *
    164     * @return object associated with the given configuration key.
    165     */
    166    @Override
    167    protected Object getPropertyInternal(final String key) {
    168        return store.get(key);
    169    }
    170
    171    /**
    172     * Check if the configuration is empty
    173     *
    174     * @return {@code true} if Configuration is empty, {@code false} otherwise.
    175     */
    176    @Override
    177    protected boolean isEmptyInternal() {
    178        return store.isEmpty();
    179    }
    180
    181    /**
    182     * {@inheritDoc} This implementation obtains the size directly from the map used as data store. So this is a rather
    183     * efficient implementation.
    184     */
    185    @Override
    186    protected int sizeInternal() {
    187        return store.size();
    188    }
    189}