001 /*--------------------------------------------------------------------------+ 002 $Id: SocketUtils.java 28668 2010-06-23 14:46:45Z heineman $ 003 | | 004 | Copyright 2005-2010 Technische Universitaet Muenchen | 005 | | 006 | Licensed under the Apache License, Version 2.0 (the "License"); | 007 | you may not use this file except in compliance with the License. | 008 | You may obtain a copy of the License at | 009 | | 010 | http://www.apache.org/licenses/LICENSE-2.0 | 011 | | 012 | Unless required by applicable law or agreed to in writing, software | 013 | distributed under the License is distributed on an "AS IS" BASIS, | 014 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 015 | See the License for the specific language governing permissions and | 016 | limitations under the License. | 017 +--------------------------------------------------------------------------*/ 018 package edu.tum.cs.commons.net; 019 020 import java.io.IOException; 021 import java.net.ServerSocket; 022 023 /** 024 * Utility methods used in conjunction with sockets. 025 * 026 * @author hummelb 027 * @author $Author: heineman $ 028 * @version $Rev: 28668 $ 029 * @levd.rating GREEN Hash: 66E2820DADBD6636110BD951A76A091E 030 */ 031 public class SocketUtils { 032 033 /** Checks whether the given TCP port is available. */ 034 public static boolean isFreePort(int portNumber) { 035 try { 036 ServerSocket socket = new ServerSocket(portNumber); 037 socket.setReuseAddress(true); 038 socket.close(); 039 return true; 040 } catch (IOException e) { 041 return false; 042 } 043 } 044 045 /** Returns a new free TCP port number */ 046 public static int getFreePort() throws IOException { 047 ServerSocket socket = new ServerSocket(0); 048 socket.setReuseAddress(true); 049 int result = socket.getLocalPort(); 050 socket.close(); 051 return result; 052 } 053 054 }