Java tutorial
/* * ------------------------------------------------------------------------------ * Hermes FTP Server * Copyright (c) 2005-2014 Lars Behnke * ------------------------------------------------------------------------------ * * This file is part of Hermes FTP Server. * * Hermes FTP Server is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Hermes FTP Server 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Hermes FTP Server; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * ------------------------------------------------------------------------------ */ package com.apporiented.hermesftp.utils; import java.net.Inet6Address; import java.net.InetAddress; import java.net.NetworkInterface; import java.net.SocketException; import java.net.UnknownHostException; import java.util.Enumeration; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Utility methods that facilitate networking. * * @author Lars Behnke */ public final class NetUtils { private static final String REGEX_POINT = "\\."; private static final String REGEX_COLON = ":"; private static final int QUADRUPLE_LEN = 4; private static final int OCTUPLE_LEN = 8; private static Log log = LogFactory.getLog(NetUtils.class); /** * Hidden constructor. */ private NetUtils() { super(); } /** * Returns the machine's network address. * * @param fallBackToLocalhost True if loopback address should be used if * there is no net. * @return The ip address. */ public static InetAddress getMachineAddress(boolean fallBackToLocalhost) { InetAddress result = null; try { Enumeration<NetworkInterface> nis = NetworkInterface.getNetworkInterfaces(); while (nis.hasMoreElements()) { NetworkInterface ni = nis.nextElement(); InetAddress ia = getMachineAddress(ni); if (ia != null) { result = ia; break; } } if (result == null) { result = InetAddress.getLocalHost(); } } catch (SocketException e) { log.error(e); } catch (UnknownHostException e) { log.error(e); } return result; } /** * Checks the IP protocol version (IPv4 or IPv6) * * @param addr The address to check. * @return True, if IPv6. */ public static boolean isIPv6(InetAddress addr) { return addr instanceof Inet6Address; } /** * Returns the network address of a particular network interface. * * @param ni The network interface. * @return The machine address of a particular network interface. */ public static InetAddress getMachineAddress(NetworkInterface ni) { Enumeration<InetAddress> addrs = ni.getInetAddresses(); InetAddress mAddr = null; while (addrs.hasMoreElements()) { InetAddress addr = addrs.nextElement(); if (addr.isSiteLocalAddress()) { mAddr = addr; } } return mAddr; } /** * Checks if SSL is available. * * @return True, if SSL is available. */ public static boolean isSSLAvailable() { // TODO search for better check. Avoid using com.sun.* packages. try { Class.forName("com.sun.net.ssl.internal.ssl.Provider"); log.info("JSSE installed."); return true; } catch (ClassNotFoundException e) { log.error("JSSE is NOT installed correctly!"); return false; } } /** * Checks if the passed IP address complies to a given pattern. * * @param ipTemplateList String list of patterns. Wild cards are allowed: 192.168.*.*, 127.0.0.1, !85.0.0.0 * @param addr The IP address to check. * @return True, if the passed IP address matches at least one of the * patterns. */ public static boolean checkIPMatch(String ipTemplateList, InetAddress addr) { if (isIPv6(addr)) { return checkIPv6Match(ipTemplateList, addr.getHostAddress()); } else { return checkIPv4Match(ipTemplateList, addr.getHostAddress()); } } /** * Checks if the passed IPv4 complies to a given pattern. * * @param ipTemplateList String list of patterns. Wild cards are allowed: 192.168.*.*, 127.0.0.1, !85.0.0.0 * @param ipStr The IP address to check. * @return True, if the passed IP address matches at least one of the * patterns. */ public static boolean checkIPv4Match(String ipTemplateList, String ipStr) { String[] chk = ipStr.split(REGEX_POINT); if (chk.length != QUADRUPLE_LEN) { throw new IllegalArgumentException("Illegal IPv4 address: " + ipStr); } boolean inverse = false; String[] ipTemplateArr = ipTemplateList.split(","); for (String anIpTemplateArr : ipTemplateArr) { String t; if (anIpTemplateArr.trim().startsWith("!")) { t = anIpTemplateArr.substring(1).trim(); inverse = true; } else { t = anIpTemplateArr.trim(); } String[] tmpl = t.split(REGEX_POINT); boolean match = true; for (int j = 0; j < tmpl.length; j++) { match &= ("*".equals(tmpl[j].trim())) || (tmpl[j].trim().equals(chk[j].trim())) ^ inverse; } if (match) { return true; } } return false; } /** * Checks if the passed IPv6 complies to a given pattern. * * @param ipTemplateList String list of patterns. Wild cards are allowed. * @param ipStr The IP address to check. * @return True, if the passed IP address matches at least one of the * patterns. */ public static boolean checkIPv6Match(String ipTemplateList, String ipStr) { String[] chk = ipStr.split(REGEX_COLON); if (chk.length != OCTUPLE_LEN) { throw new IllegalArgumentException("Illegal IPv6 address: " + ipStr); } boolean inverse = false; String[] ipTemplateArr = ipTemplateList.split(","); for (String anIpTemplateArr : ipTemplateArr) { String t; if (anIpTemplateArr.trim().startsWith("!")) { t = anIpTemplateArr.substring(1).trim(); inverse = true; } else { t = anIpTemplateArr.trim(); } String[] tmpl = t.split(REGEX_COLON); boolean match = true; for (int j = 0; j < tmpl.length; j++) { match &= ("*".equals(tmpl[j].trim())) || (tmpl[j].trim().equals(chk[j].trim())) ^ inverse; } if (match) { return true; } } return false; } }