org.everit.json.schema.internal.IPAddressValidator Maven / Gradle / Ivy

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/*
 * Copyright (C) 2011 Everit Kft. (http://www.everit.org)
 *
 * Licensed 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.everit.json.schema.internal;

import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.net.InetAddresses;

import java.net.InetAddress;

/**
 * Common superclass for {@link IPV4Validator} and {@link IPV6Validator}.
 */
public class IPAddressValidator {

    /**
     * Creates an {@link InetAddress} instance if possible and returns it, or on failure it returns
     * {@code Optional.empty()}.
     *
     * @param subject the string to be validated.
     * @return the optional validation failure message
     */
    protected Optional asInetAddress(final String subject) {
        try {
            if (InetAddresses.isInetAddress(subject)) {
                return Optional.of(InetAddresses.forString(subject));
            } else {
                return Optional.absent();
            }
        } catch (NullPointerException e) {
            return Optional.absent();
        }
    }

    /**
     * Checks an IP address.
     *
     * @param subject        the string to be validated.
     * @param expectedLength the expected length of {@code subject} - it is validated if
     *                       {@link #asInetAddress(String)} validation succeeds.
     * @param failureFormat  the {@link String#format(String, Object...) string format} of the validation failue
     *                       message. The format string will receive only the {@code subject} parameter (so it has
     *                       to be referred as {@code %s} in the format string
     * @return the optional validation failure message
     */
    protected Optional checkIpAddress(final String subject, final int expectedLength,
            final String failureFormat) {
        Optional inetAddressOptional = asInetAddress(subject);

        if (inetAddressOptional.isPresent() && inetAddressOptional.get().getAddress().length != expectedLength) {
            inetAddressOptional = Optional.absent();
        }

        return inetAddressOptional
                .transform(new Function>() {
                    @Override
                    public Optional apply(InetAddress input) {
                        return emptyString();
                    }
                })
                .or(Optional.of(String.format(failureFormat, subject)));
    }

    private Optional emptyString() {
        return Optional.absent();
    }

}