socketutil.java

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/*
 * Copyright (C) 2007 ETH Zurich
 *
 * This file is part of Fosstrak (www.fosstrak.org).
 *
 * Fosstrak is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software Foundation.
 *
 * Fosstrak 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Fosstrak; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

package org.fosstrak.reader.rprm.core.msg.util;

import java.io.IOException;
import java.net.ServerSocket;

/**
 * Utility class for socket related stuff.
 * 
 * @author Andreas F黵er, ETH Zurich Switzerland, Winter 2005/06
 *
 */

public class SocketUtil {
	/**
	 * Returns a free port number on localhost, or -1 if unable to find a free port.
	 * 
	 * @return a free port number > 1024 on localhost, or -1 if unable to find a free port
	 */
	public static int findFreePort() {
		ServerSocket socket= null;
		try {
			socket= new ServerSocket(0);
			return socket.getLocalPort();
		} catch (IOException e) { 
		} finally {
			if (socket != null) {
				try {
					socket.close();
				} catch (IOException e) {
				}
			}
		}
		return -1;		
	}	
}