001/*
002 * #%L
003 * Netarchivesuite - common
004 * %%
005 * Copyright (C) 2005 - 2014 The Royal Danish Library, the Danish State and University Library,
006 *             the National Library of France and the Austrian National Library.
007 * %%
008 * This program is free software: you can redistribute it and/or modify
009 * it under the terms of the GNU Lesser General Public License as
010 * published by the Free Software Foundation, either version 2.1 of the
011 * License, or (at your option) any later version.
012 *
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Lesser Public License for more details.
017 *
018 * You should have received a copy of the GNU General Lesser Public
019 * License along with this program.  If not, see
020 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
021 * #L%
022 */
023package dk.netarkivet.common.distribute.bitrepository;
024
025import java.net.InetAddress;
026import java.net.UnknownHostException;
027
028import org.apache.commons.lang.StringUtils;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * Provide the hostname of the machine on which the program is running.
034 */
035public class HostNameUtils {
036    /** Logging mechanism. */
037    private static Logger logger = LoggerFactory.getLogger(HostNameUtils.class);
038
039    /**
040     * disallow construction by making this private.
041     */
042    private HostNameUtils() {
043    }
044
045    /**
046     * @return the hostname of the machine as a {@link String}
047     */
048    public static String getHostName() {
049        try {
050            //Trying to get hostname through InetAddress
051            final InetAddress iAddress = InetAddress.getLocalHost();
052            String hostName = iAddress.getHostName();
053
054            //Trying to do better and get Canonical hostname
055            final String canonicalHostName = iAddress.getCanonicalHostName();
056
057            if (StringUtils.isNotEmpty(canonicalHostName)) {
058                logger.info("Local hostname (provided  by getCanonicalHostName): {}", canonicalHostName);
059                return canonicalHostName;
060            } else if (StringUtils.isNotEmpty(hostName)) {
061                logger.info("Local hostname (provided  by iAddress): {}", hostName);
062                return hostName;
063            }
064
065        } catch (UnknownHostException  e) {
066            logger.info("Failed finding hostname the standard Java way, returning: localhost", e);
067        }
068        return "localhost";
069    }
070}