| /******************************************************************************* |
| * Copyright (c) 2000, 2015 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.launching; |
| |
| |
| import java.io.IOException; |
| import java.net.ConnectException; |
| import java.net.ServerSocket; |
| import java.net.Socket; |
| import java.util.Random; |
| |
| /** |
| * Utility class to find a port to debug on. |
| * @noinstantiate This class is not intended to be instantiated by clients. |
| * @noextend This class is not intended to be subclassed by clients. |
| */ |
| public class SocketUtil { |
| private static final Random fgRandom= new Random(System.currentTimeMillis()); |
| |
| /** |
| * Returns a free port number on the specified host within the given range, |
| * or -1 if none found. |
| * |
| * @param host name or IP address of host on which to find a free port |
| * @param searchFrom the port number from which to start searching |
| * @param searchTo the port number at which to stop searching |
| * @return a free port in the specified range, or -1 of none found |
| * @deprecated Use <code>findFreePort()</code> instead. It is possible that this |
| * method can return a port that is already in use since the implementation does |
| * not bind to the given port to ensure that it is free. |
| */ |
| @Deprecated |
| public static int findUnusedLocalPort(String host, int searchFrom, int searchTo) { |
| |
| for (int i= 0; i < 10; i++) { |
| int port= getRandomPort(searchFrom, searchTo); |
| try (Socket s = new Socket(host, port)) { |
| s.getLocalPort(); // avoid warning on s being unused |
| } catch (ConnectException e) { |
| return port; |
| } catch (IOException e) { |
| } |
| } |
| return -1; |
| } |
| |
| private static int getRandomPort(int low, int high) { |
| return (int)(fgRandom.nextFloat() * (high-low)) + low; |
| } |
| |
| /** |
| * Returns a free port number on localhost, or -1 if unable to find a free port. |
| * |
| * @return a free port number on localhost, or -1 if unable to find a free port |
| * @since 3.0 |
| */ |
| public static int findFreePort() { |
| try (ServerSocket socket = new ServerSocket(0)) { |
| return socket.getLocalPort(); |
| } catch (IOException e) { |
| } |
| return -1; |
| } |
| } |