001 /* 002 * SonarQube, open source software quality management tool. 003 * Copyright (C) 2008-2014 SonarSource 004 * mailto:contact AT sonarsource DOT com 005 * 006 * SonarQube is free software; you can redistribute it and/or 007 * modify it under the terms of the GNU Lesser General Public 008 * License as published by the Free Software Foundation; either 009 * version 3 of the License, or (at your option) any later version. 010 * 011 * SonarQube is distributed in the hope that it will be useful, 012 * but WITHOUT ANY WARRANTY; without even the implied warranty of 013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 * Lesser General Public License for more details. 015 * 016 * You should have received a copy of the GNU Lesser General Public License 017 * along with this program; if not, write to the Free Software Foundation, 018 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 019 */ 020 package org.sonar.process; 021 022 import java.net.Inet4Address; 023 import java.net.InetAddress; 024 import java.net.NetworkInterface; 025 import java.net.SocketException; 026 import java.util.Enumeration; 027 028 public class LoopbackAddress { 029 030 private static InetAddress instance; 031 032 private LoopbackAddress() { 033 // only static stuff 034 } 035 036 /** 037 * Quite similar to {@code InetAddress.getLoopbackAddress()} which was introduced in Java 7. This 038 * method aims to support Java 6. It returns an IPv4 address, but not IPv6 in order to 039 * support {@code -Djava.net.preferIPv4Stack=true} which is recommended for Elasticsearch. 040 */ 041 public static InetAddress get() { 042 if (instance == null) { 043 try { 044 instance = doGet(NetworkInterface.getNetworkInterfaces()); 045 } catch (SocketException e) { 046 throw new IllegalStateException("Fail to browse network interfaces", e); 047 } 048 049 } 050 return instance; 051 } 052 053 static InetAddress doGet(Enumeration<NetworkInterface> ifaces) { 054 InetAddress result = null; 055 while (ifaces.hasMoreElements() && result == null) { 056 NetworkInterface iface = ifaces.nextElement(); 057 Enumeration<InetAddress> addresses = iface.getInetAddresses(); 058 while (addresses.hasMoreElements()) { 059 InetAddress addr = addresses.nextElement(); 060 if (addr.isLoopbackAddress() && addr instanceof Inet4Address) { 061 result = addr; 062 break; 063 } 064 } 065 } 066 if (result == null) { 067 throw new IllegalStateException("Impossible to get a IPv4 loopback address"); 068 } 069 return result; 070 } 071 }