001/**
002 * Java Web Archive Toolkit - Software to read and validate ARC, WARC
003 * and GZip files. (http://jwat.org/)
004 * Copyright 2011-2012 Netarkivet.dk (http://netarkivet.dk/)
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.jwat.common;
019
020import java.net.InetAddress;
021import java.net.UnknownHostException;
022import java.util.regex.Pattern;
023
024/**
025 * IP address parser and format validator for Ipv4 and Ipv6.
026 *
027 * @author lbihanic, selghissassi
028 */
029public final class IPAddressParser {
030
031    /** Regular expression for Ipv4 or Ipv6 address. */
032    private static final String IP_ADDRESS_REG_EXP =
033        "([0-9a-fA-F]{0,4}:){0,6}("                 // Optional IPv6 start
034        + "([0-9a-fA-F]{0,4}:[0-9a-fA-F]{1,4})|"    // True IPv6 address or
035        + "(([0-9]{1,3}\\.){3}[0-9]{1,3}))";        // Standalone or mixed IPv4 address
036
037    /** IpAddress compiled regex pattern. */
038    private static final Pattern IP_ADDRESS_PATTERN
039                                        = Pattern.compile(IP_ADDRESS_REG_EXP);
040
041    /**
042     * Checks the validity of an IP address.
043     * Supports both IP v4 and IP v6 formats.
044     * @param ipAddress the IP address
045     * @return the inetAddress of the IP address if valid, if not, null is returned
046     */
047    public static InetAddress getAddress(String ipAddress){
048        boolean isValid = (ipAddress == null) ? false
049                            : IP_ADDRESS_PATTERN.matcher(ipAddress).matches();
050        InetAddress inetAddress = null;
051        if(isValid){
052            try {
053                inetAddress = InetAddress.getByName(ipAddress);
054            } catch (UnknownHostException e) {
055                isValid = false;
056            }
057        }
058        return (isValid) ? inetAddress : null;
059    }
060
061    /**
062     * No constructor for this utility class, static access only.
063     */
064    protected IPAddressParser() {
065    }
066
067}