Java HTTP Port Find getAvailablePortsFromRange(int portMin, int portMax, int numberOfPorts)

Description

Returns a List of available ports within a given port range.

License

Open Source License

Parameter

Parameter	Description
portMin	lower bound of the port range
portMax	upper bound of the port range
numberOfPorts	number of available ports required

Return

list of available ports

Declaration

public static List<Integer> getAvailablePortsFromRange(int portMin, int portMax, int numberOfPorts) 

Method Source Code

//package com.java2s;
/*// ww  w .  j  av a2 s. c o m
 * Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. licenses this file to you under the Apache License,
 * Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

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

import java.util.ArrayList;
import java.util.List;

public class Main {
    /**
     * Returns a {@link List} of available ports within a given port range.
     *
     * @param portMin       lower bound of the port range
     * @param portMax       upper bound of the port range
     * @param numberOfPorts number of available ports required
     * @return list of available ports
     */
    public static List<Integer> getAvailablePortsFromRange(int portMin, int portMax, int numberOfPorts) {
        List<Integer> availablePorts = new ArrayList<>();

        int port = portMin;
        int portCount = 0;

        while ((portCount < numberOfPorts) && (port <= portMax)) {
            if (isPortAvailable(port)) {
                availablePorts.add(port);
                portCount++;
            }
            port++;
        }

        return availablePorts;
    }

    /**
     * Checks if the specified {@code port} number is available or closed.
     *
     * @param port the port number
     * @return true if the specified {@code port} is available or closed else false
     */
    public static boolean isPortAvailable(final int port) {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(port);
            serverSocket.setReuseAddress(true);
            return true;
        } catch (final IOException ignored) {
        } finally {
            if (serverSocket != null) {
                try {
                    serverSocket.close();
                } catch (IOException ignored) {
                }
            }
        }
        return false;
    }
}

Related

1. getAvailablePort(int prefferedPort)
2. getAvailablePort(int randomAttempts)
3. getAvailablePort(int startPort)
4. getAvailablePort(String hostname, String portRange)
5. getAvailablePorts(int basePort, int portCount)
6. getAvialablePort(final int basePort)
7. getCorrectHostnamePort(String hostPort)
8. getEffectivePort(String scheme, int specifiedPort)
9. getEphemeralPort()