Here you can find the source of isIPv6(final String ip)
public static boolean isIPv6(final String ip)
//package com.java2s; /*/*from ww w . j a va2 s .c o m*/ * * MariaDB Client for Java * * Copyright (c) 2012-2014 Monty Program Ab. * Copyright (c) 2015-2017 MariaDB Ab. * * This library is free software; you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free * Software Foundation; either version 2.1 of the License, or (at your option) * any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License * for more details. * * You should have received a copy of the GNU Lesser General Public License along * with this library; if not, write to Monty Program Ab info@montyprogram.com. * * This particular MariaDB Client for Java file is work * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to * the following copyright and notice provisions: * * Copyright (c) 2009-2011, Marcus Eriksson * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list * of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, this * list of conditions and the following disclaimer in the documentation and/or * other materials provided with the distribution. * * Neither the name of the driver nor the names of its contributors may not be * used to endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * */ import java.util.regex.Pattern; public class Main { private static final Pattern IP_V6 = Pattern.compile("^[0-9a-fA-F]{1,4}(:[0-9a-fA-F]{1,4}){7}$"); private static final Pattern IP_V6_COMPRESSED = Pattern.compile( "^(([0-9A-Fa-f]{1,4}(:[0-9A-Fa-f]{1,4}){0,5})?)" + "::(([0-9A-Fa-f]{1,4}(:[0-9A-Fa-f]{1,4}){0,5})?)$"); public static boolean isIPv6(final String ip) { return IP_V6.matcher(ip).matches() || IP_V6_COMPRESSED.matcher(ip).matches(); } }