InetAddressConverter.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.beanutils2.converters;

import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * {@link org.apache.commons.beanutils2.Converter} implementation that handles conversion to and from {@link InetAddress}.
 *
 * @since 2.0.0
 * @see <a href="https://en.wikipedia.org/wiki/Inet_address">IP Address on Wikipedia</a>
 */
public class InetAddressConverter extends AbstractConverter<InetAddress> {

    /**
     * Construct a <strong>{@link InetAddress}</strong> <em>Converter</em> that throws a {@code ConversionException} if an error occurs.
     */
    public InetAddressConverter() {
    }

    /**
     * Constructs a {@link org.apache.commons.beanutils2.Converter} that will return the specified default value if a conversion error occurs.
     *
     * @param defaultValue The default value to be returned if the value to be converted is missing or an error occurs converting the value.
     */
    public InetAddressConverter(final InetAddress defaultValue) {
        super(defaultValue);
    }

    /**
     * Converts the specified input object into an output object of the specified type.
     *
     * @param type  Data type to which this value should be converted.
     * @param value The String property value to convert.
     * @return An {@link InetAddress} which represents the configuration property value.
     * @throws NullPointerException     If the value is null.
     * @throws IllegalArgumentException If a host name was specified and the IP address couldn't be obtained.
     */
    @Override
    protected <T> T convertToType(final Class<T> type, final Object value) throws Throwable {
        if (InetAddress.class.isAssignableFrom(type)) {
            final String stringValue = toString(value);

            try {
                return type.cast(InetAddress.getByName(stringValue));
            } catch (final UnknownHostException ex) {
                throw new IllegalArgumentException("Unable to get IP address of the named host.", ex);
            }
        }

        throw conversionException(type, value);
    }

    /**
     * Gets the default type this {@code Converter} handles.
     *
     * @return The default type this {@code Converter} handles.
     * @since 2.0.0
     */
    @Override
    protected Class<InetAddress> getDefaultType() {
        return InetAddress.class;
    }
}