Java HTTP Port Find freePort()

Description

free Port

License

Open Source License

Declaration

static int freePort() 

Method Source Code

//package com.java2s;
/*/*from  w  ww.j a  v a 2  s  .  c  o  m*/
 * SonarQube, open source software quality management tool.
 * Copyright (C) 2008-2014 SonarSource
 * mailto:contact AT sonarsource DOT com
 *
 * SonarQube is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * SonarQube 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 this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

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

public class Main {
    static int freePort() {
        for (int index = 0; index < 5; index++) {
            try {
                ServerSocket socket = new ServerSocket(0);
                int unusedPort = socket.getLocalPort();
                socket.close();
                if (isValidPort(unusedPort)) {
                    return unusedPort;
                }

            } catch (IOException e) {
                throw new IllegalStateException("Can not find an open network port", e);
            }
        }
        throw new IllegalStateException("Can not find an open network port");
    }

    private static boolean isValidPort(int port) {
        return port > 1023;
    }
}

Related

1. findUnusedPort(int preferredPort)
2. findUnusedPorts(int numPorts)
3. freePort()
4. freePort()
5. freePort()
6. freePort()
7. freePort(int suggestedPort)
8. get(int port, String applicationRoot, String resource, String path)
9. getAllHostNames(String hostName, int portNumber, String bindingUser)