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 */
020package org.sonar.process;
021
022import org.apache.commons.io.IOUtils;
023
024import java.io.IOException;
025import java.net.InetSocketAddress;
026import java.net.ServerSocket;
027
028public class NetworkUtils {
029
030  private NetworkUtils() {
031    // only static stuff
032  }
033
034  /**
035   * Get an unused port
036   */
037  public static int freePort() {
038    ServerSocket socket = null;
039    try  {
040      socket = new ServerSocket();
041      socket.setReuseAddress(true);
042      socket.bind(new InetSocketAddress(0));
043      return socket.getLocalPort();
044
045    } catch (IOException e) {
046      throw new IllegalStateException("Can not find a free network port", e);
047
048    } finally {
049      IOUtils.closeQuietly(socket);
050    }
051  }
052}