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.net.ServerSocket;
025
026public class NetworkUtils {
027
028  private NetworkUtils() {
029    // only static stuff
030  }
031
032  /**
033   * Get an unused port
034   */
035  public static int freePort() {
036    ServerSocket s = null;
037    try {
038      s = new ServerSocket(0);
039      return s.getLocalPort();
040    } catch (Exception e) {
041      throw new IllegalStateException("Can not find an open network port", e);
042    } finally {
043      IOUtils.closeQuietly(s);
044    }
045  }
046}