DataConfiguration.java

/*
 * 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;

import java.awt.Color;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.function.Supplier;

import org.apache.commons.configuration2.convert.ConversionHandler;
import org.apache.commons.configuration2.convert.DefaultConversionHandler;
import org.apache.commons.configuration2.ex.ConversionException;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;

/**
 * Decorator providing additional getters for any Configuration. This extended Configuration supports more types:
 * <ul>
 * <li>{@link java.net.URL}</li>
 * <li>{@link java.util.Locale}</li>
 * <li>{@link java.util.Date}</li>
 * <li>{@link java.util.Calendar}</li>
 * <li>{@link java.awt.Color}</li>
 * <li>{@link java.net.InetAddress}</li>
 * <li>{@code javax.mail.internet.InternetAddress} (requires Javamail in the classpath)</li>
 * <li>{@code jakarta.mail.internet.InternetAddress} (requires Javamail 2.+ in the classpath)</li>
 * <li>{@link Enum}</li>
 * </ul>
 *
 * Lists and arrays are available for all types.<br>
 * Note that this class is only a thin wrapper over functionality already provided by {@link AbstractConfiguration}.
 * Basically, the generic {@code get()}, and {@code getCollection()} methods are used to actually perform data
 * conversions.
 *
 * <p>
 * <strong>Example</strong>
 * </p>
 *
 * Configuration file {@code config.properties}:
 *
 * <pre>
 * title.color = #0000FF
 * remote.host = 192.168.0.53
 * default.locales = fr,en,de
 * email.contact = dev@test.org, tester@test.org
 * </pre>
 *
 * Usage:
 *
 * <pre>
 * DataConfiguration config = new DataConfiguration(new PropertiesConfiguration("config.properties"));
 *
 * // retrieve a property using a specialized getter
 * Color color = config.getColor("title.color");
 *
 * // retrieve a property using a generic getter
 * InetAddress host = (InetAddress) config.get(InetAddress.class, "remote.host");
 * Locale[] locales = (Locale[]) config.getArray(Locale.class, "default.locales");
 * List contacts = config.getList(InternetAddress.class, "email.contact");
 * </pre>
 *
 * <p>
 * <strong>Dates</strong>
 * </p>
 *
 * Date objects are expected to be formatted with the pattern {@code yyyy-MM-dd HH:mm:ss}. This default format can be
 * changed by specifying another format in the getters, or by putting a date format in the configuration under the key
 * {@code org.apache.commons.configuration.format.date}. Alternatively, the date format can also be specified via the
 * {@code ConversionHandler} used by a configuration instance:
 *
 * <pre>
 * DefaultConversionHandler handler = new DefaultConversionHandler();
 * handler.setDateFormat("mm/dd/yyyy");
 * config.setConversionHandler(handler);
 * </pre>
 *
 * @since 1.1
 */
public class DataConfiguration extends AbstractConfiguration {

    /**
     * A specialized {@code ConversionHandler} implementation which allows overriding the date format pattern. This class
     * takes care that the format pattern can be defined as a property of the wrapped configuration or temporarily passed
     * when calling a conversion method.
     */
    private final class DataConversionHandler extends DefaultConversionHandler {
        /**
         * {@inheritDoc} This implementation checks for a defined data format in the following order:
         * <ul>
         * <li>If a temporary date format is set for the current call, it is used.</li>
         * <li>If a date format is specified in this configuration using the {@code DATE_FORMAT_KEY} property, it is used.</li>
         * <li>Otherwise, the date format set for the original conversion handler is used if available.</li>
         * </ul>
         */
        @Override
        public String getDateFormat() {
            if (StringUtils.isNotEmpty(TEMP_DATE_FORMAT.get())) {
                return TEMP_DATE_FORMAT.get();
            }
            if (containsKey(DATE_FORMAT_KEY)) {
                return getDefaultDateFormat();
            }

            final DefaultConversionHandler orgHandler = getOriginalConversionHandler();
            return orgHandler != null ? orgHandler.getDateFormat() : null;
        }
    }

    /** The key of the property storing the user-defined date format. */
    public static final String DATE_FORMAT_KEY = "org.apache.commons.configuration.format.date";

    /** The default format for dates. */
    public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";

    /** Empty array constant. */
    private static final URL[] EMPTY_URL_ARRAY = {};

    /** Empty array constant. */
    private static final URI[] EMPTY_URI_ARRAY = {};

    /** Empty array constant. */
    private static final Locale[] EMPTY_LOCALE_ARRAY = {};

    /** Empty array constant. */
    private static final Date[] EMPTY_DATE_ARRAY = {};

    /** Empty array constant. */
    private static final Color[] EMPTY_COLOR_ARRAY = {};

    /** Empty array constant. */
    private static final Calendar[] EMPTY_CALENDARD_ARRAY = {};

    /** Empty array constant. */
    private static final BigInteger[] EMPTY_BIG_INTEGER_ARRAY = {};

    /** Empty array constant. */
    private static final BigDecimal[] EMPTY_BIG_DECIMAL_ARRAY = {};

    /** Stores temporary date formats. */
    private static final ThreadLocal<String> TEMP_DATE_FORMAT = new ThreadLocal<>();

    /** Stores the wrapped configuration. */
    private final Configuration configuration;

    /** A special conversion handler object used by this configuration. */
    private final ConversionHandler dataConversionHandler;

    /**
     * Creates a new instance of {@code DataConfiguration} and sets the wrapped configuration.
     *
     * @param configuration the wrapped configuration
     */
    public DataConfiguration(final Configuration configuration) {
        this.configuration = Objects.requireNonNull(configuration, "configuration");
        this.dataConversionHandler = new DataConversionHandler();
    }

    @Override
    protected void addPropertyDirect(final String key, final Object value) {
        if (configuration instanceof AbstractConfiguration) {
            ((AbstractConfiguration) configuration).addPropertyDirect(key, value);
        } else {
            configuration.addProperty(key, value);
        }
    }

    @Override
    protected void addPropertyInternal(final String key, final Object obj) {
        configuration.addProperty(key, obj);
    }

    private <R> R applyTempDateFormat(final String format, final Supplier<R> supplier) {
        TEMP_DATE_FORMAT.set(format);
        try {
            return supplier.get();
        } finally {
            TEMP_DATE_FORMAT.remove();
        }
    }

    @Override
    protected void clearPropertyDirect(final String key) {
        configuration.clearProperty(key);
    }

    @Override
    protected boolean containsKeyInternal(final String key) {
        return configuration.containsKey(key);
    }

    /**
     * Tests whether this configuration contains one or more matches to this value. This operation stops at first
     * match but may be more expensive than the containsKey method.
     * @since 2.11.0
     */
    @Override
    protected boolean containsValueInternal(final Object value) {
        return configuration.containsValue(value);
    }

    /**
     * Gets an array of BigDecimals associated with the given configuration key. If the key doesn't map to an existing object
     * an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated BigDecimal array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigDecimals.
     */
    public BigDecimal[] getBigDecimalArray(final String key) {
        return getBigDecimalArray(key, EMPTY_BIG_DECIMAL_ARRAY);
    }

    /**
     * Gets an array of BigDecimals associated with the given configuration key. If the key doesn't map to an existing object
     * an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated BigDecimal array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigDecimals.
     */
    public BigDecimal[] getBigDecimalArray(final String key, final BigDecimal... defaultValue) {
        return get(BigDecimal[].class, key, defaultValue);
    }

    /**
     * Gets a list of BigDecimals associated with the given configuration key. If the key doesn't map to an existing object
     * an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated BigDecimal list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigDecimals.
     */
    public List<BigDecimal> getBigDecimalList(final String key) {
        return getBigDecimalList(key, new ArrayList<>());
    }

    /**
     * Gets a list of BigDecimals associated with the given configuration key. If the key doesn't map to an existing object,
     * the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of BigDecimals.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigDecimals.
     */
    public List<BigDecimal> getBigDecimalList(final String key, final List<BigDecimal> defaultValue) {
        return getList(BigDecimal.class, key, defaultValue);
    }

    /**
     * Gets an array of BigIntegers associated with the given configuration key. If the key doesn't map to an existing object
     * an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated BigInteger array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigIntegers.
     */
    public BigInteger[] getBigIntegerArray(final String key) {
        return getBigIntegerArray(key, EMPTY_BIG_INTEGER_ARRAY);
    }

    /**
     * Gets an array of BigIntegers associated with the given configuration key. If the key doesn't map to an existing object
     * an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated BigInteger array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigIntegers.
     */
    public BigInteger[] getBigIntegerArray(final String key, final BigInteger... defaultValue) {
        return get(BigInteger[].class, key, defaultValue);
    }

    /**
     * Gets a list of BigIntegers associated with the given configuration key. If the key doesn't map to an existing object
     * an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated BigInteger list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigIntegers.
     */
    public List<BigInteger> getBigIntegerList(final String key) {
        return getBigIntegerList(key, new ArrayList<>());
    }

    /**
     * Gets a list of BigIntegers associated with the given configuration key. If the key doesn't map to an existing object,
     * the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of BigIntegers.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of BigIntegers.
     */
    public List<BigInteger> getBigIntegerList(final String key, final List<BigInteger> defaultValue) {
        return getList(BigInteger.class, key, defaultValue);
    }

    /**
     * Gets an array of boolean primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated boolean array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of booleans.
     */
    public boolean[] getBooleanArray(final String key) {
        return (boolean[]) getArray(Boolean.TYPE, key);
    }

    /**
     * Gets an array of boolean primitives associated with the given configuration key. If the key doesn't map to an existing
     * object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated boolean array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of booleans.
     */
    public boolean[] getBooleanArray(final String key, final boolean... defaultValue) {
        return get(boolean[].class, key, defaultValue);
    }

    /**
     * Gets a list of Boolean objects associated with the given configuration key. If the key doesn't map to an existing
     * object an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Boolean list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of booleans.
     */
    public List<Boolean> getBooleanList(final String key) {
        return getBooleanList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Boolean objects associated with the given configuration key. If the key doesn't map to an existing
     * object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Booleans.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of booleans.
     */
    public List<Boolean> getBooleanList(final String key, final List<Boolean> defaultValue) {
        return getList(Boolean.class, key, defaultValue);
    }

    /**
     * Gets an array of byte primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated byte array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of bytes.
     */
    public byte[] getByteArray(final String key) {
        return getByteArray(key, ArrayUtils.EMPTY_BYTE_ARRAY);
    }

    /**
     * Gets an array of byte primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated byte array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of bytes.
     */
    public byte[] getByteArray(final String key, final byte... defaultValue) {
        return get(byte[].class, key, defaultValue);
    }

    /**
     * Gets a list of Byte objects associated with the given configuration key. If the key doesn't map to an existing object
     * an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Byte list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of bytes.
     */
    public List<Byte> getByteList(final String key) {
        return getByteList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Byte objects associated with the given configuration key. If the key doesn't map to an existing object,
     * the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Bytes.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of bytes.
     */
    public List<Byte> getByteList(final String key, final List<Byte> defaultValue) {
        return getList(Byte.class, key, defaultValue);
    }

    /**
     * Gets a Calendar associated with the given configuration key. If the property is a String, it will be parsed with the
     * format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern.
     *
     * @param key The configuration key.
     * @return The associated Calendar.
     * @throws ConversionException is thrown if the key maps to an object that is not a Calendar.
     */
    public Calendar getCalendar(final String key) {
        return get(Calendar.class, key);
    }

    /**
     * Gets a Calendar associated with the given configuration key. If the property is a String, it will be parsed with the
     * format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated Calendar.
     * @throws ConversionException is thrown if the key maps to an object that is not a Calendar.
     */
    public Calendar getCalendar(final String key, final Calendar defaultValue) {
        return getCalendar(key, defaultValue, null);
    }

    /**
     * Gets a Calendar associated with the given configuration key. If the property is a String, it will be parsed with the
     * specified format pattern. If the key doesn't map to an existing object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Calendar.
     * @throws ConversionException is thrown if the key maps to an object that is not a Calendar.
     */
    public Calendar getCalendar(final String key, final Calendar defaultValue, final String format) {
        return applyTempDateFormat(format, () -> get(Calendar.class, key, defaultValue));
    }

    /**
     * Gets a Calendar associated with the given configuration key. If the property is a String, it will be parsed with the
     * specified format pattern.
     *
     * @param key The configuration key.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Calendar
     * @throws ConversionException is thrown if the key maps to an object that is not a Calendar.
     */
    public Calendar getCalendar(final String key, final String format) {
        final Calendar value = getCalendar(key, null, format);
        if (value != null) {
            return value;
        }
        if (isThrowExceptionOnMissing()) {
            throw new NoSuchElementException('\'' + key + "' doesn't map to an existing object");
        }
        return null;
    }

    /**
     * Gets an array of Calendars associated with the given configuration key. If the property is a list of Strings, they
     * will be parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined
     * with the {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object an empty array is
     * returned.
     *
     * @param key The configuration key.
     * @return The associated Calendar array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public Calendar[] getCalendarArray(final String key) {
        return getCalendarArray(key, EMPTY_CALENDARD_ARRAY);
    }

    /**
     * Gets an array of Calendars associated with the given configuration key. If the property is a list of Strings, they
     * will be parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined
     * with the {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object an empty array is
     * returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated Calendar array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public Calendar[] getCalendarArray(final String key, final Calendar... defaultValue) {
        return getCalendarArray(key, defaultValue, null);
    }

    /**
     * Gets an array of Calendars associated with the given configuration key. If the property is a list of Strings, they
     * will be parsed with the specified format pattern. If the key doesn't map to an existing object, the default value is
     * returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Calendar array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public Calendar[] getCalendarArray(final String key, final Calendar[] defaultValue, final String format) {
        return applyTempDateFormat(format, () -> get(Calendar[].class, key, defaultValue));
    }

    /**
     * Gets an array of Calendars associated with the given configuration key. If the property is a list of Strings, they
     * will be parsed with the specified format pattern. If the key doesn't map to an existing object an empty array is
     * returned.
     *
     * @param key The configuration key.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Calendar array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public Calendar[] getCalendarArray(final String key, final String format) {
        return getCalendarArray(key, EMPTY_CALENDARD_ARRAY, format);
    }

    /**
     * Gets a list of Calendars associated with the given configuration key. If the property is a list of Strings, they will
     * be parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with
     * the {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Calendar list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public List<Calendar> getCalendarList(final String key) {
        return getCalendarList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Calendars associated with the given configuration key. If the property is a list of Strings, they will
     * be parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with
     * the {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object, the default value is
     * returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated Calendar list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public List<Calendar> getCalendarList(final String key, final List<Calendar> defaultValue) {
        return getCalendarList(key, defaultValue, null);
    }

    /**
     * Gets a list of Calendars associated with the given configuration key. If the property is a list of Strings, they will
     * be parsed with the specified format pattern. If the key doesn't map to an existing object, the default value is
     * returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Calendar list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public List<Calendar> getCalendarList(final String key, final List<Calendar> defaultValue, final String format) {
        return applyTempDateFormat(format, () -> getList(Calendar.class, key, defaultValue));
    }

    /**
     * Gets a list of Calendars associated with the given configuration key. If the property is a list of Strings, they will
     * be parsed with the specified format pattern. If the key doesn't map to an existing object an empty list is returned.
     *
     * @param key The configuration key.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Calendar list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Calendars.
     */
    public List<Calendar> getCalendarList(final String key, final String format) {
        return getCalendarList(key, new ArrayList<>(), format);
    }

    /**
     * Gets a Color associated with the given configuration key.
     *
     * @param key The configuration key.
     * @return The associated Color.
     * @throws ConversionException is thrown if the key maps to an object that is not a Color.
     */
    public Color getColor(final String key) {
        return get(Color.class, key);
    }

    /**
     * Gets a Color associated with the given configuration key. If the key doesn't map to an existing object, the default
     * value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated Color.
     * @throws ConversionException is thrown if the key maps to an object that is not a Color.
     */
    public Color getColor(final String key, final Color defaultValue) {
        return get(Color.class, key, defaultValue);
    }

    /**
     * Gets an array of Colors associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated Color array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Colors.
     */
    public Color[] getColorArray(final String key) {
        return getColorArray(key, EMPTY_COLOR_ARRAY);
    }

    /**
     * Gets an array of Colors associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated Color array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Colors.
     */
    public Color[] getColorArray(final String key, final Color... defaultValue) {
        return get(Color[].class, key, defaultValue);
    }

    /**
     * Gets a list of Colors associated with the given configuration key. If the key doesn't map to an existing object an
     * empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Color list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Colors.
     */
    public List<Color> getColorList(final String key) {
        return getColorList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Colors associated with the given configuration key. If the key doesn't map to an existing object, the
     * default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Colors.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Colors.
     */
    public List<Color> getColorList(final String key, final List<Color> defaultValue) {
        return getList(Color.class, key, defaultValue);
    }

    /**
     * Gets the configuration decorated by this DataConfiguration.
     *
     * @return the wrapped configuration
     */
    public Configuration getConfiguration() {
        return configuration;
    }

    /**
     * {@inheritDoc} This implementation returns the special conversion handler used by this configuration instance.
     */
    @Override
    public ConversionHandler getConversionHandler() {
        return dataConversionHandler;
    }

    /**
     * Gets a Date associated with the given configuration key. If the property is a String, it will be parsed with the
     * format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern.
     *
     * @param key The configuration key.
     * @return The associated Date.
     * @throws ConversionException is thrown if the key maps to an object that is not a Date.
     */
    public Date getDate(final String key) {
        return get(Date.class, key);
    }

    /**
     * Gets a Date associated with the given configuration key. If the property is a String, it will be parsed with the
     * format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated Date.
     * @throws ConversionException is thrown if the key maps to an object that is not a Date.
     */
    public Date getDate(final String key, final Date defaultValue) {
        return getDate(key, defaultValue, null);
    }

    /**
     * Gets a Date associated with the given configuration key. If the property is a String, it will be parsed with the
     * specified format pattern. If the key doesn't map to an existing object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Date.
     * @throws ConversionException is thrown if the key maps to an object that is not a Date.
     */
    public Date getDate(final String key, final Date defaultValue, final String format) {
        return applyTempDateFormat(format, () -> get(Date.class, key, defaultValue));
    }

    /**
     * Gets a Date associated with the given configuration key. If the property is a String, it will be parsed with the
     * specified format pattern.
     *
     * @param key The configuration key.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Date
     * @throws ConversionException is thrown if the key maps to an object that is not a Date.
     */
    public Date getDate(final String key, final String format) {
        final Date value = getDate(key, null, format);
        if (value != null) {
            return value;
        }
        if (isThrowExceptionOnMissing()) {
            throw new NoSuchElementException('\'' + key + "' doesn't map to an existing object");
        }
        return null;
    }

    /**
     * Gets an array of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated Date array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public Date[] getDateArray(final String key) {
        return getDateArray(key, EMPTY_DATE_ARRAY);
    }

    /**
     * Gets an array of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated Date array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public Date[] getDateArray(final String key, final Date... defaultValue) {
        return getDateArray(key, defaultValue, null);
    }

    /**
     * Gets an array of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the specified format pattern. If the key doesn't map to an existing object, the default value is
     * returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Date array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public Date[] getDateArray(final String key, final Date[] defaultValue, final String format) {
        return applyTempDateFormat(format, () -> get(Date[].class, key, defaultValue));
    }

    /**
     * Gets an array of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the specified format pattern. If the key doesn't map to an existing object an empty array is returned.
     *
     * @param key The configuration key.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Date array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public Date[] getDateArray(final String key, final String format) {
        return getDateArray(key, EMPTY_DATE_ARRAY, format);
    }

    /**
     * Gets a list of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object, a new list is returned.
     *
     * @param key The configuration key.
     * @return The associated Date list if the key is found. If the key doesn't map to an existing object, a new list is returned.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public List<Date> getDateList(final String key) {
        return getDateList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the format defined by the user in the {@link #DATE_FORMAT_KEY} property, or if it's not defined with the
     * {@link #DEFAULT_DATE_FORMAT} pattern. If the key doesn't map to an existing object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated Date list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public List<Date> getDateList(final String key, final List<Date> defaultValue) {
        return getDateList(key, defaultValue, null);
    }

    /**
     * Gets a list of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the specified format pattern. If the key doesn't map to an existing object, the default value is
     * returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Date list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public List<Date> getDateList(final String key, final List<Date> defaultValue, final String format) {
        return applyTempDateFormat(format, () -> getList(Date.class, key, defaultValue));
    }

    /**
     * Gets a list of Dates associated with the given configuration key. If the property is a list of Strings, they will be
     * parsed with the specified format pattern. If the key doesn't map to an existing object an empty list is returned.
     *
     * @param key The configuration key.
     * @param format The non-localized {@link java.text.DateFormat} pattern.
     * @return The associated Date list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Dates.
     */
    public List<Date> getDateList(final String key, final String format) {
        return getDateList(key, new ArrayList<>(), format);
    }

    /**
     * Gets the date format specified by the user in the DATE_FORMAT_KEY property, or the default format otherwise.
     *
     * @return the default date format
     */
    private String getDefaultDateFormat() {
        return getString(DATE_FORMAT_KEY, DEFAULT_DATE_FORMAT);
    }

    /**
     * Gets an array of double primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated double array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of doubles.
     */
    public double[] getDoubleArray(final String key) {
        return getDoubleArray(key, ArrayUtils.EMPTY_DOUBLE_ARRAY);
    }

    /**
     * Gets an array of double primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated double array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of doubles.
     */
    public double[] getDoubleArray(final String key, final double... defaultValue) {
        return get(double[].class, key, defaultValue);
    }

    /**
     * Gets a list of Double objects associated with the given configuration key. If the key doesn't map to an existing
     * object an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Double list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of doubles.
     */
    public List<Double> getDoubleList(final String key) {
        return getDoubleList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Double objects associated with the given configuration key. If the key doesn't map to an existing
     * object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Doubles.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of doubles.
     */
    public List<Double> getDoubleList(final String key, final List<Double> defaultValue) {
        return getList(Double.class, key, defaultValue);
    }

    /**
     * Gets an array of float primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated float array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of floats.
     */
    public float[] getFloatArray(final String key) {
        return getFloatArray(key, ArrayUtils.EMPTY_FLOAT_ARRAY);
    }

    /**
     * Gets an array of float primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated float array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of floats.
     */
    public float[] getFloatArray(final String key, final float... defaultValue) {
        return get(float[].class, key, defaultValue);
    }

    /**
     * Gets a list of Float objects associated with the given configuration key. If the key doesn't map to an existing object
     * an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Float list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of floats.
     */
    public List<Float> getFloatList(final String key) {
        return getFloatList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Float objects associated with the given configuration key. If the key doesn't map to an existing
     * object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Floats.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of floats.
     */
    public List<Float> getFloatList(final String key, final List<Float> defaultValue) {
        return getList(Float.class, key, defaultValue);
    }

    /**
     * Gets an array of int primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated int array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of integers.
     */
    public int[] getIntArray(final String key) {
        return getIntArray(key, ArrayUtils.EMPTY_INT_ARRAY);
    }

    /**
     * Gets an array of int primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated int array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of integers.
     */
    public int[] getIntArray(final String key, final int... defaultValue) {
        return get(int[].class, key, defaultValue);
    }

    /**
     * Gets a list of Integer objects associated with the given configuration key. If the key doesn't map to an existing
     * object an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Integer list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of integers.
     */
    public List<Integer> getIntegerList(final String key) {
        return getIntegerList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Integer objects associated with the given configuration key. If the key doesn't map to an existing
     * object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Integers.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of integers.
     */
    public List<Integer> getIntegerList(final String key, final List<Integer> defaultValue) {
        return getList(Integer.class, key, defaultValue);
    }

    @Override
    protected Iterator<String> getKeysInternal() {
        return configuration.getKeys();
    }

    /**
     * Gets a Locale associated with the given configuration key.
     *
     * @param key The configuration key.
     * @return The associated Locale.
     * @throws ConversionException is thrown if the key maps to an object that is not a Locale.
     */
    public Locale getLocale(final String key) {
        return get(Locale.class, key);
    }

    /**
     * Gets a Locale associated with the given configuration key. If the key doesn't map to an existing object, the default
     * value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated Locale.
     * @throws ConversionException is thrown if the key maps to an object that is not a Locale.
     */
    public Locale getLocale(final String key, final Locale defaultValue) {
        return get(Locale.class, key, defaultValue);
    }

    /**
     * Gets an array of Locales associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated Locale array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Locales.
     */
    public Locale[] getLocaleArray(final String key) {
        return getLocaleArray(key, EMPTY_LOCALE_ARRAY);
    }

    /**
     * Gets an array of Locales associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated Locale array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Locales.
     */
    public Locale[] getLocaleArray(final String key, final Locale... defaultValue) {
        return get(Locale[].class, key, defaultValue);
    }

    /**
     * Gets a list of Locales associated with the given configuration key. If the key doesn't map to an existing object an
     * empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Locale list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Locales.
     */
    public List<Locale> getLocaleList(final String key) {
        return getLocaleList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Locales associated with the given configuration key. If the key doesn't map to an existing object, the
     * default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Locales.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of Locales.
     */
    public List<Locale> getLocaleList(final String key, final List<Locale> defaultValue) {
        return getList(Locale.class, key, defaultValue);
    }

    /**
     * Gets an array of long primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated long array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of longs.
     */
    public long[] getLongArray(final String key) {
        return getLongArray(key, ArrayUtils.EMPTY_LONG_ARRAY);
    }

    /**
     * Gets an array of long primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated long array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of longs.
     */
    public long[] getLongArray(final String key, final long... defaultValue) {
        return get(long[].class, key, defaultValue);
    }

    /**
     * Gets a list of Long objects associated with the given configuration key. If the key doesn't map to an existing object
     * an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Long list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of longs.
     */
    public List<Long> getLongList(final String key) {
        return getLongList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Long objects associated with the given configuration key. If the key doesn't map to an existing object,
     * the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Longs.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of longs.
     */
    public List<Long> getLongList(final String key, final List<Long> defaultValue) {
        return getList(Long.class, key, defaultValue);
    }

    /**
     * Gets the original conversion handler set for this configuration. If this is not a
     * {@code DefaultConversionHandler}, result is <strong>null</strong>.
     *
     * @return the original conversion handler or <strong>null</strong>
     */
    private DefaultConversionHandler getOriginalConversionHandler() {
        final ConversionHandler handler = super.getConversionHandler();
        return (DefaultConversionHandler) (handler instanceof DefaultConversionHandler ? handler : null);
    }

    @Override
    protected Object getPropertyInternal(final String key) {
        return configuration.getProperty(key);
    }

    /**
     * Gets an array of short primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated short array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of shorts.
     */
    public short[] getShortArray(final String key) {
        return getShortArray(key, ArrayUtils.EMPTY_SHORT_ARRAY);
    }

    /**
     * Gets an array of short primitives associated with the given configuration key. If the key doesn't map to an existing
     * object an empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated short array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of shorts.
     */
    public short[] getShortArray(final String key, final short... defaultValue) {
        return get(short[].class, key, defaultValue);
    }

    /**
     * Gets a list of Short objects associated with the given configuration key. If the key doesn't map to an existing object
     * an empty list is returned.
     *
     * @param key The configuration key.
     * @return The associated Short list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of shorts.
     */
    public List<Short> getShortList(final String key) {
        return getShortList(key, new ArrayList<>());
    }

    /**
     * Gets a list of Short objects associated with the given configuration key. If the key doesn't map to an existing
     * object, the default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of Shorts.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of shorts.
     */
    public List<Short> getShortList(final String key, final List<Short> defaultValue) {
        return getList(Short.class, key, defaultValue);
    }

    /**
     * Gets an URI associated with the given configuration key.
     *
     * @param key The configuration key.
     * @return The associated URI.
     * @throws ConversionException is thrown if the key maps to an object that is not an URI.
     */
    public URI getURI(final String key) {
        return get(URI.class, key);
    }

    /**
     * Gets an URI associated with the given configuration key. If the key doesn't map to an existing object, the default
     * value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated URI.
     * @throws ConversionException is thrown if the key maps to an object that is not an URI.
     */
    public URI getURI(final String key, final URI defaultValue) {
        return get(URI.class, key, defaultValue);
    }

    /**
     * Gets an array of URIs associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated URI array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URIs.
     */
    public URI[] getURIArray(final String key) {
        return getURIArray(key, EMPTY_URI_ARRAY);
    }

    /**
     * Gets an array of URIs associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated URI array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URIs.
     */
    public URI[] getURIArray(final String key, final URI... defaultValue) {
        return get(URI[].class, key, defaultValue);
    }

    /**
     * Gets a list of URIs associated with the given configuration key. If the key doesn't map to an existing object an empty
     * list is returned.
     *
     * @param key The configuration key.
     * @return The associated URI list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URIs.
     */
    public List<URI> getURIList(final String key) {
        return getURIList(key, new ArrayList<>());
    }

    /**
     * Gets a list of URIs associated with the given configuration key. If the key doesn't map to an existing object, the
     * default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of URIs.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URIs.
     */
    public List<URI> getURIList(final String key, final List<URI> defaultValue) {
        return getList(URI.class, key, defaultValue);
    }

    /**
     * Gets an URL associated with the given configuration key.
     *
     * @param key The configuration key.
     * @return The associated URL.
     * @throws ConversionException is thrown if the key maps to an object that is not an URL.
     */
    public URL getURL(final String key) {
        return get(URL.class, key);
    }

    /**
     * Gets an URL associated with the given configuration key. If the key doesn't map to an existing object, the default
     * value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated URL.
     * @throws ConversionException is thrown if the key maps to an object that is not an URL.
     */
    public URL getURL(final String key, final URL defaultValue) {
        return get(URL.class, key, defaultValue);
    }

    /**
     * Gets an array of URLs associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @return The associated URL array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URLs.
     */
    public URL[] getURLArray(final String key) {
        return getURLArray(key, EMPTY_URL_ARRAY);
    }

    /**
     * Gets an array of URLs associated with the given configuration key. If the key doesn't map to an existing object an
     * empty array is returned.
     *
     * @param key The configuration key.
     * @param defaultValue the default value, which will be returned if the property is not found
     * @return The associated URL array if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URLs.
     */
    public URL[] getURLArray(final String key, final URL... defaultValue) {
        return get(URL[].class, key, defaultValue);
    }

    /**
     * Gets a list of URLs associated with the given configuration key. If the key doesn't map to an existing object an empty
     * list is returned.
     *
     * @param key The configuration key.
     * @return The associated URL list if the key is found.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URLs.
     */
    public List<URL> getURLList(final String key) {
        return getURLList(key, new ArrayList<>());
    }

    /**
     * Gets a list of URLs associated with the given configuration key. If the key doesn't map to an existing object, the
     * default value is returned.
     *
     * @param key The configuration key.
     * @param defaultValue The default value.
     * @return The associated List of URLs.
     * @throws ConversionException is thrown if the key maps to an object that is not a list of URLs.
     */
    public List<URL> getURLList(final String key, final List<URL> defaultValue) {
        return getList(URL.class, key, defaultValue);
    }

    @Override
    protected boolean isEmptyInternal() {
        return configuration.isEmpty();
    }

    @Override
    protected void setPropertyInternal(final String key, final Object value) {
        configuration.setProperty(key, value);
    }
}