Here you can find the source of getEphemeralPort()
public static int getEphemeralPort()
//package com.java2s; /**/*www . j a v a 2 s . c o m*/ * Kodo Kojo - Software factory done right * Copyright ? 2016 Kodo Kojo (infos@kodokojo.io) * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ import java.io.IOException; import java.net.InetSocketAddress; import java.net.ServerSocket; public class Main { public static int getEphemeralPort() { int port = 0; try { ServerSocket serverSocket = new ServerSocket(0); port = ((InetSocketAddress) serverSocket.getLocalSocketAddress()).getPort(); serverSocket.close(); } catch (IOException e) { e.printStackTrace(); } return port; } }