Java InetAddress Create getFreePort(InetAddress ipAddress)

Description

get Free Port

License

Open Source License

Declaration

public static int getFreePort(InetAddress ipAddress) 

Method Source Code

//package com.java2s;
/*/*from   w  w  w .  j a va2s . com*/
 * Copyright (c) 2015, Alachisoft. All Rights Reserved.
 *
 * Licensed 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.DatagramSocket;
import java.net.InetAddress;

import java.net.ServerSocket;

public class Main {
    public static int getFreePort(InetAddress ipAddress) {
        int port = getFreeTCPPort(ipAddress);
        int retry = 20;
        while (retry > 0) {
            if (isUDPPortFree(port, ipAddress)) {
                return port;
            }
            retry -= 1;
        }
        return 0;
    }

    public static int getFreeTCPPort(InetAddress ipAddress) {
        ServerSocket ss = null;
        try {
            ss = new ServerSocket(0);
            return ss.getLocalPort();
        } catch (IOException iOE) {
        } finally {
            if (ss != null) {
                try {
                    ss.close();
                } catch (IOException e) {
                }
            }
        }
        return 0;
    }

    public static boolean isUDPPortFree(int port, InetAddress addr) {
        DatagramSocket ds = null;
        try {
            ds = new DatagramSocket(port, addr);
            //ds.setReuseAddress(true);
            return true;
        } catch (IOException io) {
        } finally {
            if (ds != null) {
                ds.close();
            }
        }
        return false;
    }
}

Related

1. getClassPart(InetAddress ip, int partNumber)
2. getConnectionAddress(InetAddress addr)
3. getDestinationInetAddress(URI uri)
4. getExternalAddresses(InetAddress[] addresses)
5. getFQDN(final InetAddress addr)
6. getFreeSocket(InetAddress bindAddress, int portRangeStart, int portRangeEnd)
7. getFreeTCPPort(InetAddress ipAddress)
8. getFullHostName(InetAddress netAddress)
9. getHashFromAddress(final InetAddress address)